diff --git a/installers/charm/osm-ro/.gitignore b/installers/charm/osm-ro/.gitignore
new file mode 100644
index 0000000..87d0a58
--- /dev/null
+++ b/installers/charm/osm-ro/.gitignore
@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+venv/
+build/
+*.charm
+.tox/
+.coverage
+coverage.xml
+__pycache__/
+*.py[cod]
+.vscode
\ No newline at end of file
diff --git a/installers/charm/osm-ro/.jujuignore b/installers/charm/osm-ro/.jujuignore
new file mode 100644
index 0000000..17c7a8b
--- /dev/null
+++ b/installers/charm/osm-ro/.jujuignore
@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+/venv
+*.py[cod]
+*.charm
diff --git a/installers/charm/osm-ro/CONTRIBUTING.md b/installers/charm/osm-ro/CONTRIBUTING.md
new file mode 100644
index 0000000..61f2a0a
--- /dev/null
+++ b/installers/charm/osm-ro/CONTRIBUTING.md
@@ -0,0 +1,78 @@
+<!-- Copyright 2022 Canonical Ltd.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may
+not use this file except in compliance with the License. You may obtain
+a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations
+under the License.
+
+For those usages not covered by the Apache License, Version 2.0 please
+contact: legal@canonical.com
+
+To get in touch with the maintainers, please contact:
+osm-charmers@lists.launchpad.net -->
+
+# Contributing
+
+## Overview
+
+This documents explains the processes and practices recommended for contributing enhancements to
+this operator.
+
+- Generally, before developing enhancements to this charm, you should consider [opening an issue
+  ](https://osm.etsi.org/bugzilla/enter_bug.cgi?product=OSM) explaining your use case. (Component=devops, version=master)
+- If you would like to chat with us about your use-cases or proposed implementation, you can reach
+  us at [OSM Juju public channel](https://opensourcemano.slack.com/archives/C027KJGPECA).
+- Familiarising yourself with the [Charmed Operator Framework](https://juju.is/docs/sdk) library
+  will help you a lot when working on new features or bug fixes.
+- All enhancements require review before being merged. Code review typically examines
+  - code quality
+  - test coverage
+  - user experience for Juju administrators this charm.
+- Please help us out in ensuring easy to review branches by rebasing your gerrit patch onto
+  the `master` branch.
+
+## Developing
+
+You can use the environments created by `tox` for development:
+
+```shell
+tox --notest -e unit
+source .tox/unit/bin/activate
+```
+
+### Testing
+
+```shell
+tox -e fmt           # update your code according to linting rules
+tox -e lint          # code style
+tox -e unit          # unit tests
+tox -e integration   # integration tests
+tox                  # runs 'lint' and 'unit' environments
+```
+
+## Build charm
+
+Build the charm in this git repository using:
+
+```shell
+charmcraft pack
+```
+
+### Deploy
+
+```bash
+# Create a model
+juju add-model dev
+# Enable DEBUG logging
+juju model-config logging-config="<root>=INFO;unit=DEBUG"
+# Deploy the charm
+juju deploy ./osm-ro_ubuntu-22.04-amd64.charm \
+    --resource ro-image=opensourcemano/ro:testing-daily --series jammy
+```
diff --git a/installers/charm/osm-ro/LICENSE b/installers/charm/osm-ro/LICENSE
new file mode 100644
index 0000000..7e9d504
--- /dev/null
+++ b/installers/charm/osm-ro/LICENSE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
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+      "Licensor" shall mean the copyright owner or entity authorized by
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+      "Legal Entity" shall mean the union of the acting entity and all
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      transformation or translation of a Source form, including but
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+
+      "Work" shall mean the work of authorship, whether in Source or
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+      "Contribution" shall mean any work of authorship, including
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+   4. Redistribution. You may reproduce and distribute copies of the
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+      meet the following conditions:
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+      (a) You must give any other recipients of the Work or
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+
+      (b) You must cause any modified files to carry prominent notices
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+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright 2022 Canonical Ltd.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/installers/charm/osm-ro/README.md b/installers/charm/osm-ro/README.md
new file mode 100644
index 0000000..44250f9
--- /dev/null
+++ b/installers/charm/osm-ro/README.md
@@ -0,0 +1,42 @@
+<!-- Copyright 2022 Canonical Ltd.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may
+not use this file except in compliance with the License. You may obtain
+a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations
+under the License.
+
+For those usages not covered by the Apache License, Version 2.0 please
+contact: legal@canonical.com
+
+To get in touch with the maintainers, please contact:
+osm-charmers@lists.launchpad.net -->
+
+<!-- 
+Avoid using this README file for information that is maintained or published elsewhere, e.g.:
+
+* metadata.yaml > published on Charmhub
+* documentation > published on (or linked to from) Charmhub
+* detailed contribution guide > documentation or CONTRIBUTING.md
+
+Use links instead. 
+-->
+
+# OSM RO
+
+Charmhub package name: osm-ro
+More information: https://charmhub.io/osm-ro
+
+## Other resources
+
+* [Read more](https://osm.etsi.org/docs/user-guide/latest/) 
+
+* [Contributing](https://osm.etsi.org/gitweb/?p=osm/devops.git;a=blob;f=installers/charm/osm-ro/CONTRIBUTING.md)
+
+* See the [Juju SDK documentation](https://juju.is/docs/sdk) for more information about developing and improving charms.
diff --git a/installers/charm/osm-ro/actions.yaml b/installers/charm/osm-ro/actions.yaml
new file mode 100644
index 0000000..0d73468
--- /dev/null
+++ b/installers/charm/osm-ro/actions.yaml
@@ -0,0 +1,26 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+#
+# This file populates the Actions tab on Charmhub.
+# See https://juju.is/docs/some-url-to-be-determined/ for a checklist and guidance.
+
+get-debug-mode-information:
+  description: Get information to debug the container
diff --git a/installers/charm/osm-ro/charmcraft.yaml b/installers/charm/osm-ro/charmcraft.yaml
new file mode 100644
index 0000000..f5e3ff3
--- /dev/null
+++ b/installers/charm/osm-ro/charmcraft.yaml
@@ -0,0 +1,36 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+
+type: charm
+bases:
+  - build-on:
+      - name: "ubuntu"
+        channel: "22.04"
+    run-on:
+      - name: "ubuntu"
+        channel: "22.04"
+
+parts:
+  charm:
+    # build-packages:
+    #   - git
+    prime:
+      - files/*
diff --git a/installers/charm/osm-ro/config.yaml b/installers/charm/osm-ro/config.yaml
new file mode 100644
index 0000000..036eecd
--- /dev/null
+++ b/installers/charm/osm-ro/config.yaml
@@ -0,0 +1,103 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+#
+# This file populates the Configure tab on Charmhub.
+# See https://juju.is/docs/some-url-to-be-determined/ for a checklist and guidance.
+
+options:
+  log-level:
+    default: "INFO"
+    description: |
+      Set the Logging Level.
+
+      Options:
+        - TRACE
+        - DEBUG
+        - INFO
+        - WARN
+        - ERROR
+        - FATAL
+    type: string
+  database-commonkey:
+    description: Database COMMON KEY
+    type: string
+    default: osm
+  certificates:
+    type: string
+    description: |
+      comma-separated list of <name>:<content> certificates.
+      Where:
+        name: name of the file for the certificate
+        content: base64 content of the certificate
+      The path for the files is /certs.
+
+  # Debug-mode options
+  debug-mode:
+    type: boolean
+    description: |
+      Great for OSM Developers! (Not recommended for production deployments)
+        
+      This action activates the Debug Mode, which sets up the container to be ready for debugging.
+      As part of the setup, SSH is enabled and a VSCode workspace file is automatically populated.
+
+      After enabling the debug-mode, execute the following command to get the information you need
+      to start debugging:
+        `juju run-action <unit name> get-debug-mode-information --wait`
+      
+      The previous command returns the command you need to execute, and the SSH password that was set.
+
+      See also:
+        - https://charmhub.io/osm-ro/configure#ro-hostpath
+        - https://charmhub.io/osm-ro/configure#common-hostpath
+    default: false
+  ro-hostpath:
+    type: string
+    description: |
+      Set this config to the local path of the ro module to persist the changes done during the
+      debug-mode session.
+
+      Example:
+        $ git clone "https://osm.etsi.org/gerrit/osm/RO" /home/ubuntu/ro
+        $ juju config ro ro-hostpath=/home/ubuntu/ro
+
+      This configuration only applies if option `debug-mode` is set to true. 
+
+  common-hostpath:
+    type: string
+    description: |
+      Set this config to the local path of the common module to persist the changes done during the
+      debug-mode session.
+
+      Example:
+        $ git clone "https://osm.etsi.org/gerrit/osm/common" /home/ubuntu/common
+        $ juju config ro common-hostpath=/home/ubuntu/common
+
+      This configuration only applies if option `debug-mode` is set to true.
+
+  period_refresh_active:
+    type: int
+    description: |
+      Updates the VNF status from VIM for every given period of time seconds.
+      Values equal or greater than 60 is allowed.
+      Disable the updates from VIM by setting -1.
+      Example:
+        $ juju config ro period_refresh_active=-1
+        $ juju config ro period_refresh_active=100
diff --git a/installers/charm/osm-ro/files/vscode-workspace.json b/installers/charm/osm-ro/files/vscode-workspace.json
new file mode 100644
index 0000000..5ab0913
--- /dev/null
+++ b/installers/charm/osm-ro/files/vscode-workspace.json
@@ -0,0 +1,34 @@
+{
+    "folders": [
+        {"path": "/usr/lib/python3/dist-packages/osm_ng_ro"},
+        {"path": "/usr/lib/python3/dist-packages/osm_common"},
+        {"path": "/usr/lib/python3/dist-packages/osm_ro_plugin"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_arista_cloudvision"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_dpb"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_dynpac"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_floodlightof"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_ietfl2vpn"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_juniper_contrail"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_odlof"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_onos_vpls"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rosdn_onosof"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rovim_aws"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rovim_azure"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rovim_gcp"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rovim_openstack"},
+        {"path": "/usr/lib/python3/dist-packages/osm_rovim_vmware"},
+    ],
+    "launch": {
+        "configurations": [
+            {
+                "module": "osm_ng_ro.ro_main",
+                "name": "NG RO",
+                "request": "launch",
+                "type": "python",
+                "justMyCode": false,
+            }
+        ],
+        "version": "0.2.0",
+    },
+    "settings": {},
+}
\ No newline at end of file
diff --git a/installers/charm/osm-ro/lib/charms/data_platform_libs/v0/data_interfaces.py b/installers/charm/osm-ro/lib/charms/data_platform_libs/v0/data_interfaces.py
new file mode 100644
index 0000000..b3da5aa
--- /dev/null
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@@ -0,0 +1,1130 @@
+# Copyright 2023 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Library to manage the relation for the data-platform products.
+
+This library contains the Requires and Provides classes for handling the relation
+between an application and multiple managed application supported by the data-team:
+MySQL, Postgresql, MongoDB, Redis,  and Kakfa.
+
+### Database (MySQL, Postgresql, MongoDB, and Redis)
+
+#### Requires Charm
+This library is a uniform interface to a selection of common database
+metadata, with added custom events that add convenience to database management,
+and methods to consume the application related data.
+
+
+Following an example of using the DatabaseCreatedEvent, in the context of the
+application charm code:
+
+```python
+
+from charms.data_platform_libs.v0.data_interfaces import (
+    DatabaseCreatedEvent,
+    DatabaseRequires,
+)
+
+class ApplicationCharm(CharmBase):
+    # Application charm that connects to database charms.
+
+    def __init__(self, *args):
+        super().__init__(*args)
+
+        # Charm events defined in the database requires charm library.
+        self.database = DatabaseRequires(self, relation_name="database", database_name="database")
+        self.framework.observe(self.database.on.database_created, self._on_database_created)
+
+    def _on_database_created(self, event: DatabaseCreatedEvent) -> None:
+        # Handle the created database
+
+        # Create configuration file for app
+        config_file = self._render_app_config_file(
+            event.username,
+            event.password,
+            event.endpoints,
+        )
+
+        # Start application with rendered configuration
+        self._start_application(config_file)
+
+        # Set active status
+        self.unit.status = ActiveStatus("received database credentials")
+```
+
+As shown above, the library provides some custom events to handle specific situations,
+which are listed below:
+
+-  database_created: event emitted when the requested database is created.
+-  endpoints_changed: event emitted when the read/write endpoints of the database have changed.
+-  read_only_endpoints_changed: event emitted when the read-only endpoints of the database
+  have changed. Event is not triggered if read/write endpoints changed too.
+
+If it is needed to connect multiple database clusters to the same relation endpoint
+the application charm can implement the same code as if it would connect to only
+one database cluster (like the above code example).
+
+To differentiate multiple clusters connected to the same relation endpoint
+the application charm can use the name of the remote application:
+
+```python
+
+def _on_database_created(self, event: DatabaseCreatedEvent) -> None:
+    # Get the remote app name of the cluster that triggered this event
+    cluster = event.relation.app.name
+```
+
+It is also possible to provide an alias for each different database cluster/relation.
+
+So, it is possible to differentiate the clusters in two ways.
+The first is to use the remote application name, i.e., `event.relation.app.name`, as above.
+
+The second way is to use different event handlers to handle each cluster events.
+The implementation would be something like the following code:
+
+```python
+
+from charms.data_platform_libs.v0.data_interfaces import (
+    DatabaseCreatedEvent,
+    DatabaseRequires,
+)
+
+class ApplicationCharm(CharmBase):
+    # Application charm that connects to database charms.
+
+    def __init__(self, *args):
+        super().__init__(*args)
+
+        # Define the cluster aliases and one handler for each cluster database created event.
+        self.database = DatabaseRequires(
+            self,
+            relation_name="database",
+            database_name="database",
+            relations_aliases = ["cluster1", "cluster2"],
+        )
+        self.framework.observe(
+            self.database.on.cluster1_database_created, self._on_cluster1_database_created
+        )
+        self.framework.observe(
+            self.database.on.cluster2_database_created, self._on_cluster2_database_created
+        )
+
+    def _on_cluster1_database_created(self, event: DatabaseCreatedEvent) -> None:
+        # Handle the created database on the cluster named cluster1
+
+        # Create configuration file for app
+        config_file = self._render_app_config_file(
+            event.username,
+            event.password,
+            event.endpoints,
+        )
+        ...
+
+    def _on_cluster2_database_created(self, event: DatabaseCreatedEvent) -> None:
+        # Handle the created database on the cluster named cluster2
+
+        # Create configuration file for app
+        config_file = self._render_app_config_file(
+            event.username,
+            event.password,
+            event.endpoints,
+        )
+        ...
+
+```
+
+### Provider Charm
+
+Following an example of using the DatabaseRequestedEvent, in the context of the
+database charm code:
+
+```python
+from charms.data_platform_libs.v0.data_interfaces import DatabaseProvides
+
+class SampleCharm(CharmBase):
+
+    def __init__(self, *args):
+        super().__init__(*args)
+        # Charm events defined in the database provides charm library.
+        self.provided_database = DatabaseProvides(self, relation_name="database")
+        self.framework.observe(self.provided_database.on.database_requested,
+            self._on_database_requested)
+        # Database generic helper
+        self.database = DatabaseHelper()
+
+    def _on_database_requested(self, event: DatabaseRequestedEvent) -> None:
+        # Handle the event triggered by a new database requested in the relation
+        # Retrieve the database name using the charm library.
+        db_name = event.database
+        # generate a new user credential
+        username = self.database.generate_user()
+        password = self.database.generate_password()
+        # set the credentials for the relation
+        self.provided_database.set_credentials(event.relation.id, username, password)
+        # set other variables for the relation event.set_tls("False")
+```
+As shown above, the library provides a custom event (database_requested) to handle
+the situation when an application charm requests a new database to be created.
+It's preferred to subscribe to this event instead of relation changed event to avoid
+creating a new database when other information other than a database name is
+exchanged in the relation databag.
+
+### Kafka
+
+This library is the interface to use and interact with the Kafka charm. This library contains
+custom events that add convenience to manage Kafka, and provides methods to consume the
+application related data.
+
+#### Requirer Charm
+
+```python
+
+from charms.data_platform_libs.v0.data_interfaces import (
+    BootstrapServerChangedEvent,
+    KafkaRequires,
+    TopicCreatedEvent,
+)
+
+class ApplicationCharm(CharmBase):
+
+    def __init__(self, *args):
+        super().__init__(*args)
+        self.kafka = KafkaRequires(self, "kafka_client", "test-topic")
+        self.framework.observe(
+            self.kafka.on.bootstrap_server_changed, self._on_kafka_bootstrap_server_changed
+        )
+        self.framework.observe(
+            self.kafka.on.topic_created, self._on_kafka_topic_created
+        )
+
+    def _on_kafka_bootstrap_server_changed(self, event: BootstrapServerChangedEvent):
+        # Event triggered when a bootstrap server was changed for this application
+
+        new_bootstrap_server = event.bootstrap_server
+        ...
+
+    def _on_kafka_topic_created(self, event: TopicCreatedEvent):
+        # Event triggered when a topic was created for this application
+        username = event.username
+        password = event.password
+        tls = event.tls
+        tls_ca= event.tls_ca
+        bootstrap_server event.bootstrap_server
+        consumer_group_prefic = event.consumer_group_prefix
+        zookeeper_uris = event.zookeeper_uris
+        ...
+
+```
+
+As shown above, the library provides some custom events to handle specific situations,
+which are listed below:
+
+- topic_created: event emitted when the requested topic is created.
+- bootstrap_server_changed: event emitted when the bootstrap server have changed.
+- credential_changed: event emitted when the credentials of Kafka changed.
+
+### Provider Charm
+
+Following the previous example, this is an example of the provider charm.
+
+```python
+class SampleCharm(CharmBase):
+
+from charms.data_platform_libs.v0.data_interfaces import (
+    KafkaProvides,
+    TopicRequestedEvent,
+)
+
+    def __init__(self, *args):
+        super().__init__(*args)
+
+        # Default charm events.
+        self.framework.observe(self.on.start, self._on_start)
+
+        # Charm events defined in the Kafka Provides charm library.
+        self.kafka_provider = KafkaProvides(self, relation_name="kafka_client")
+        self.framework.observe(self.kafka_provider.on.topic_requested, self._on_topic_requested)
+        # Kafka generic helper
+        self.kafka = KafkaHelper()
+
+    def _on_topic_requested(self, event: TopicRequestedEvent):
+        # Handle the on_topic_requested event.
+
+        topic = event.topic
+        relation_id = event.relation.id
+        # set connection info in the databag relation
+        self.kafka_provider.set_bootstrap_server(relation_id, self.kafka.get_bootstrap_server())
+        self.kafka_provider.set_credentials(relation_id, username=username, password=password)
+        self.kafka_provider.set_consumer_group_prefix(relation_id, ...)
+        self.kafka_provider.set_tls(relation_id, "False")
+        self.kafka_provider.set_zookeeper_uris(relation_id, ...)
+
+```
+As shown above, the library provides a custom event (topic_requested) to handle
+the situation when an application charm requests a new topic to be created.
+It is preferred to subscribe to this event instead of relation changed event to avoid
+creating a new topic when other information other than a topic name is
+exchanged in the relation databag.
+"""
+
+import json
+import logging
+from abc import ABC, abstractmethod
+from collections import namedtuple
+from datetime import datetime
+from typing import List, Optional
+
+from ops.charm import (
+    CharmBase,
+    CharmEvents,
+    RelationChangedEvent,
+    RelationEvent,
+    RelationJoinedEvent,
+)
+from ops.framework import EventSource, Object
+from ops.model import Relation
+
+# The unique Charmhub library identifier, never change it
+LIBID = "6c3e6b6680d64e9c89e611d1a15f65be"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 7
+
+PYDEPS = ["ops>=2.0.0"]
+
+logger = logging.getLogger(__name__)
+
+Diff = namedtuple("Diff", "added changed deleted")
+Diff.__doc__ = """
+A tuple for storing the diff between two data mappings.
+
+added - keys that were added
+changed - keys that still exist but have new values
+deleted - key that were deleted"""
+
+
+def diff(event: RelationChangedEvent, bucket: str) -> Diff:
+    """Retrieves the diff of the data in the relation changed databag.
+
+    Args:
+        event: relation changed event.
+        bucket: bucket of the databag (app or unit)
+
+    Returns:
+        a Diff instance containing the added, deleted and changed
+            keys from the event relation databag.
+    """
+    # Retrieve the old data from the data key in the application relation databag.
+    old_data = json.loads(event.relation.data[bucket].get("data", "{}"))
+    # Retrieve the new data from the event relation databag.
+    new_data = {
+        key: value for key, value in event.relation.data[event.app].items() if key != "data"
+    }
+
+    # These are the keys that were added to the databag and triggered this event.
+    added = new_data.keys() - old_data.keys()
+    # These are the keys that were removed from the databag and triggered this event.
+    deleted = old_data.keys() - new_data.keys()
+    # These are the keys that already existed in the databag,
+    # but had their values changed.
+    changed = {key for key in old_data.keys() & new_data.keys() if old_data[key] != new_data[key]}
+    # Convert the new_data to a serializable format and save it for a next diff check.
+    event.relation.data[bucket].update({"data": json.dumps(new_data)})
+
+    # Return the diff with all possible changes.
+    return Diff(added, changed, deleted)
+
+
+# Base DataProvides and DataRequires
+
+
+class DataProvides(Object, ABC):
+    """Base provides-side of the data products relation."""
+
+    def __init__(self, charm: CharmBase, relation_name: str) -> None:
+        super().__init__(charm, relation_name)
+        self.charm = charm
+        self.local_app = self.charm.model.app
+        self.local_unit = self.charm.unit
+        self.relation_name = relation_name
+        self.framework.observe(
+            charm.on[relation_name].relation_changed,
+            self._on_relation_changed,
+        )
+
+    def _diff(self, event: RelationChangedEvent) -> Diff:
+        """Retrieves the diff of the data in the relation changed databag.
+
+        Args:
+            event: relation changed event.
+
+        Returns:
+            a Diff instance containing the added, deleted and changed
+                keys from the event relation databag.
+        """
+        return diff(event, self.local_app)
+
+    @abstractmethod
+    def _on_relation_changed(self, event: RelationChangedEvent) -> None:
+        """Event emitted when the relation data has changed."""
+        raise NotImplementedError
+
+    def fetch_relation_data(self) -> dict:
+        """Retrieves data from relation.
+
+        This function can be used to retrieve data from a relation
+        in the charm code when outside an event callback.
+
+        Returns:
+            a dict of the values stored in the relation data bag
+                for all relation instances (indexed by the relation id).
+        """
+        data = {}
+        for relation in self.relations:
+            data[relation.id] = {
+                key: value for key, value in relation.data[relation.app].items() if key != "data"
+            }
+        return data
+
+    def _update_relation_data(self, relation_id: int, data: dict) -> None:
+        """Updates a set of key-value pairs in the relation.
+
+        This function writes in the application data bag, therefore,
+        only the leader unit can call it.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            data: dict containing the key-value pairs
+                that should be updated in the relation.
+        """
+        if self.local_unit.is_leader():
+            relation = self.charm.model.get_relation(self.relation_name, relation_id)
+            relation.data[self.local_app].update(data)
+
+    @property
+    def relations(self) -> List[Relation]:
+        """The list of Relation instances associated with this relation_name."""
+        return list(self.charm.model.relations[self.relation_name])
+
+    def set_credentials(self, relation_id: int, username: str, password: str) -> None:
+        """Set credentials.
+
+        This function writes in the application data bag, therefore,
+        only the leader unit can call it.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            username: user that was created.
+            password: password of the created user.
+        """
+        self._update_relation_data(
+            relation_id,
+            {
+                "username": username,
+                "password": password,
+            },
+        )
+
+    def set_tls(self, relation_id: int, tls: str) -> None:
+        """Set whether TLS is enabled.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            tls: whether tls is enabled (True or False).
+        """
+        self._update_relation_data(relation_id, {"tls": tls})
+
+    def set_tls_ca(self, relation_id: int, tls_ca: str) -> None:
+        """Set the TLS CA in the application relation databag.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            tls_ca: TLS certification authority.
+        """
+        self._update_relation_data(relation_id, {"tls_ca": tls_ca})
+
+
+class DataRequires(Object, ABC):
+    """Requires-side of the relation."""
+
+    def __init__(
+        self,
+        charm,
+        relation_name: str,
+        extra_user_roles: str = None,
+    ):
+        """Manager of base client relations."""
+        super().__init__(charm, relation_name)
+        self.charm = charm
+        self.extra_user_roles = extra_user_roles
+        self.local_app = self.charm.model.app
+        self.local_unit = self.charm.unit
+        self.relation_name = relation_name
+        self.framework.observe(
+            self.charm.on[relation_name].relation_joined, self._on_relation_joined_event
+        )
+        self.framework.observe(
+            self.charm.on[relation_name].relation_changed, self._on_relation_changed_event
+        )
+
+    @abstractmethod
+    def _on_relation_joined_event(self, event: RelationJoinedEvent) -> None:
+        """Event emitted when the application joins the relation."""
+        raise NotImplementedError
+
+    @abstractmethod
+    def _on_relation_changed_event(self, event: RelationChangedEvent) -> None:
+        raise NotImplementedError
+
+    def fetch_relation_data(self) -> dict:
+        """Retrieves data from relation.
+
+        This function can be used to retrieve data from a relation
+        in the charm code when outside an event callback.
+        Function cannot be used in `*-relation-broken` events and will raise an exception.
+
+        Returns:
+            a dict of the values stored in the relation data bag
+                for all relation instances (indexed by the relation ID).
+        """
+        data = {}
+        for relation in self.relations:
+            data[relation.id] = {
+                key: value for key, value in relation.data[relation.app].items() if key != "data"
+            }
+        return data
+
+    def _update_relation_data(self, relation_id: int, data: dict) -> None:
+        """Updates a set of key-value pairs in the relation.
+
+        This function writes in the application data bag, therefore,
+        only the leader unit can call it.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            data: dict containing the key-value pairs
+                that should be updated in the relation.
+        """
+        if self.local_unit.is_leader():
+            relation = self.charm.model.get_relation(self.relation_name, relation_id)
+            relation.data[self.local_app].update(data)
+
+    def _diff(self, event: RelationChangedEvent) -> Diff:
+        """Retrieves the diff of the data in the relation changed databag.
+
+        Args:
+            event: relation changed event.
+
+        Returns:
+            a Diff instance containing the added, deleted and changed
+                keys from the event relation databag.
+        """
+        return diff(event, self.local_unit)
+
+    @property
+    def relations(self) -> List[Relation]:
+        """The list of Relation instances associated with this relation_name."""
+        return [
+            relation
+            for relation in self.charm.model.relations[self.relation_name]
+            if self._is_relation_active(relation)
+        ]
+
+    @staticmethod
+    def _is_relation_active(relation: Relation):
+        try:
+            _ = repr(relation.data)
+            return True
+        except RuntimeError:
+            return False
+
+    @staticmethod
+    def _is_resource_created_for_relation(relation: Relation):
+        return (
+            "username" in relation.data[relation.app] and "password" in relation.data[relation.app]
+        )
+
+    def is_resource_created(self, relation_id: Optional[int] = None) -> bool:
+        """Check if the resource has been created.
+
+        This function can be used to check if the Provider answered with data in the charm code
+        when outside an event callback.
+
+        Args:
+            relation_id (int, optional): When provided the check is done only for the relation id
+                provided, otherwise the check is done for all relations
+
+        Returns:
+            True or False
+
+        Raises:
+            IndexError: If relation_id is provided but that relation does not exist
+        """
+        if relation_id is not None:
+            try:
+                relation = [relation for relation in self.relations if relation.id == relation_id][
+                    0
+                ]
+                return self._is_resource_created_for_relation(relation)
+            except IndexError:
+                raise IndexError(f"relation id {relation_id} cannot be accessed")
+        else:
+            return (
+                all(
+                    [
+                        self._is_resource_created_for_relation(relation)
+                        for relation in self.relations
+                    ]
+                )
+                if self.relations
+                else False
+            )
+
+
+# General events
+
+
+class ExtraRoleEvent(RelationEvent):
+    """Base class for data events."""
+
+    @property
+    def extra_user_roles(self) -> Optional[str]:
+        """Returns the extra user roles that were requested."""
+        return self.relation.data[self.relation.app].get("extra-user-roles")
+
+
+class AuthenticationEvent(RelationEvent):
+    """Base class for authentication fields for events."""
+
+    @property
+    def username(self) -> Optional[str]:
+        """Returns the created username."""
+        return self.relation.data[self.relation.app].get("username")
+
+    @property
+    def password(self) -> Optional[str]:
+        """Returns the password for the created user."""
+        return self.relation.data[self.relation.app].get("password")
+
+    @property
+    def tls(self) -> Optional[str]:
+        """Returns whether TLS is configured."""
+        return self.relation.data[self.relation.app].get("tls")
+
+    @property
+    def tls_ca(self) -> Optional[str]:
+        """Returns TLS CA."""
+        return self.relation.data[self.relation.app].get("tls-ca")
+
+
+# Database related events and fields
+
+
+class DatabaseProvidesEvent(RelationEvent):
+    """Base class for database events."""
+
+    @property
+    def database(self) -> Optional[str]:
+        """Returns the database that was requested."""
+        return self.relation.data[self.relation.app].get("database")
+
+
+class DatabaseRequestedEvent(DatabaseProvidesEvent, ExtraRoleEvent):
+    """Event emitted when a new database is requested for use on this relation."""
+
+
+class DatabaseProvidesEvents(CharmEvents):
+    """Database events.
+
+    This class defines the events that the database can emit.
+    """
+
+    database_requested = EventSource(DatabaseRequestedEvent)
+
+
+class DatabaseRequiresEvent(RelationEvent):
+    """Base class for database events."""
+
+    @property
+    def endpoints(self) -> Optional[str]:
+        """Returns a comma separated list of read/write endpoints."""
+        return self.relation.data[self.relation.app].get("endpoints")
+
+    @property
+    def read_only_endpoints(self) -> Optional[str]:
+        """Returns a comma separated list of read only endpoints."""
+        return self.relation.data[self.relation.app].get("read-only-endpoints")
+
+    @property
+    def replset(self) -> Optional[str]:
+        """Returns the replicaset name.
+
+        MongoDB only.
+        """
+        return self.relation.data[self.relation.app].get("replset")
+
+    @property
+    def uris(self) -> Optional[str]:
+        """Returns the connection URIs.
+
+        MongoDB, Redis, OpenSearch.
+        """
+        return self.relation.data[self.relation.app].get("uris")
+
+    @property
+    def version(self) -> Optional[str]:
+        """Returns the version of the database.
+
+        Version as informed by the database daemon.
+        """
+        return self.relation.data[self.relation.app].get("version")
+
+
+class DatabaseCreatedEvent(AuthenticationEvent, DatabaseRequiresEvent):
+    """Event emitted when a new database is created for use on this relation."""
+
+
+class DatabaseEndpointsChangedEvent(AuthenticationEvent, DatabaseRequiresEvent):
+    """Event emitted when the read/write endpoints are changed."""
+
+
+class DatabaseReadOnlyEndpointsChangedEvent(AuthenticationEvent, DatabaseRequiresEvent):
+    """Event emitted when the read only endpoints are changed."""
+
+
+class DatabaseRequiresEvents(CharmEvents):
+    """Database events.
+
+    This class defines the events that the database can emit.
+    """
+
+    database_created = EventSource(DatabaseCreatedEvent)
+    endpoints_changed = EventSource(DatabaseEndpointsChangedEvent)
+    read_only_endpoints_changed = EventSource(DatabaseReadOnlyEndpointsChangedEvent)
+
+
+# Database Provider and Requires
+
+
+class DatabaseProvides(DataProvides):
+    """Provider-side of the database relations."""
+
+    on = DatabaseProvidesEvents()
+
+    def __init__(self, charm: CharmBase, relation_name: str) -> None:
+        super().__init__(charm, relation_name)
+
+    def _on_relation_changed(self, event: RelationChangedEvent) -> None:
+        """Event emitted when the relation has changed."""
+        # Only the leader should handle this event.
+        if not self.local_unit.is_leader():
+            return
+
+        # Check which data has changed to emit customs events.
+        diff = self._diff(event)
+
+        # Emit a database requested event if the setup key (database name and optional
+        # extra user roles) was added to the relation databag by the application.
+        if "database" in diff.added:
+            self.on.database_requested.emit(event.relation, app=event.app, unit=event.unit)
+
+    def set_endpoints(self, relation_id: int, connection_strings: str) -> None:
+        """Set database primary connections.
+
+        This function writes in the application data bag, therefore,
+        only the leader unit can call it.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            connection_strings: database hosts and ports comma separated list.
+        """
+        self._update_relation_data(relation_id, {"endpoints": connection_strings})
+
+    def set_read_only_endpoints(self, relation_id: int, connection_strings: str) -> None:
+        """Set database replicas connection strings.
+
+        This function writes in the application data bag, therefore,
+        only the leader unit can call it.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            connection_strings: database hosts and ports comma separated list.
+        """
+        self._update_relation_data(relation_id, {"read-only-endpoints": connection_strings})
+
+    def set_replset(self, relation_id: int, replset: str) -> None:
+        """Set replica set name in the application relation databag.
+
+        MongoDB only.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            replset: replica set name.
+        """
+        self._update_relation_data(relation_id, {"replset": replset})
+
+    def set_uris(self, relation_id: int, uris: str) -> None:
+        """Set the database connection URIs in the application relation databag.
+
+        MongoDB, Redis, and OpenSearch only.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            uris: connection URIs.
+        """
+        self._update_relation_data(relation_id, {"uris": uris})
+
+    def set_version(self, relation_id: int, version: str) -> None:
+        """Set the database version in the application relation databag.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            version: database version.
+        """
+        self._update_relation_data(relation_id, {"version": version})
+
+
+class DatabaseRequires(DataRequires):
+    """Requires-side of the database relation."""
+
+    on = DatabaseRequiresEvents()
+
+    def __init__(
+        self,
+        charm,
+        relation_name: str,
+        database_name: str,
+        extra_user_roles: str = None,
+        relations_aliases: List[str] = None,
+    ):
+        """Manager of database client relations."""
+        super().__init__(charm, relation_name, extra_user_roles)
+        self.database = database_name
+        self.relations_aliases = relations_aliases
+
+        # Define custom event names for each alias.
+        if relations_aliases:
+            # Ensure the number of aliases does not exceed the maximum
+            # of connections allowed in the specific relation.
+            relation_connection_limit = self.charm.meta.requires[relation_name].limit
+            if len(relations_aliases) != relation_connection_limit:
+                raise ValueError(
+                    f"The number of aliases must match the maximum number of connections allowed in the relation. "
+                    f"Expected {relation_connection_limit}, got {len(relations_aliases)}"
+                )
+
+            for relation_alias in relations_aliases:
+                self.on.define_event(f"{relation_alias}_database_created", DatabaseCreatedEvent)
+                self.on.define_event(
+                    f"{relation_alias}_endpoints_changed", DatabaseEndpointsChangedEvent
+                )
+                self.on.define_event(
+                    f"{relation_alias}_read_only_endpoints_changed",
+                    DatabaseReadOnlyEndpointsChangedEvent,
+                )
+
+    def _assign_relation_alias(self, relation_id: int) -> None:
+        """Assigns an alias to a relation.
+
+        This function writes in the unit data bag.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+        """
+        # If no aliases were provided, return immediately.
+        if not self.relations_aliases:
+            return
+
+        # Return if an alias was already assigned to this relation
+        # (like when there are more than one unit joining the relation).
+        if (
+            self.charm.model.get_relation(self.relation_name, relation_id)
+            .data[self.local_unit]
+            .get("alias")
+        ):
+            return
+
+        # Retrieve the available aliases (the ones that weren't assigned to any relation).
+        available_aliases = self.relations_aliases[:]
+        for relation in self.charm.model.relations[self.relation_name]:
+            alias = relation.data[self.local_unit].get("alias")
+            if alias:
+                logger.debug("Alias %s was already assigned to relation %d", alias, relation.id)
+                available_aliases.remove(alias)
+
+        # Set the alias in the unit relation databag of the specific relation.
+        relation = self.charm.model.get_relation(self.relation_name, relation_id)
+        relation.data[self.local_unit].update({"alias": available_aliases[0]})
+
+    def _emit_aliased_event(self, event: RelationChangedEvent, event_name: str) -> None:
+        """Emit an aliased event to a particular relation if it has an alias.
+
+        Args:
+            event: the relation changed event that was received.
+            event_name: the name of the event to emit.
+        """
+        alias = self._get_relation_alias(event.relation.id)
+        if alias:
+            getattr(self.on, f"{alias}_{event_name}").emit(
+                event.relation, app=event.app, unit=event.unit
+            )
+
+    def _get_relation_alias(self, relation_id: int) -> Optional[str]:
+        """Returns the relation alias.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+
+        Returns:
+            the relation alias or None if the relation was not found.
+        """
+        for relation in self.charm.model.relations[self.relation_name]:
+            if relation.id == relation_id:
+                return relation.data[self.local_unit].get("alias")
+        return None
+
+    def _on_relation_joined_event(self, event: RelationJoinedEvent) -> None:
+        """Event emitted when the application joins the database relation."""
+        # If relations aliases were provided, assign one to the relation.
+        self._assign_relation_alias(event.relation.id)
+
+        # Sets both database and extra user roles in the relation
+        # if the roles are provided. Otherwise, sets only the database.
+        if self.extra_user_roles:
+            self._update_relation_data(
+                event.relation.id,
+                {
+                    "database": self.database,
+                    "extra-user-roles": self.extra_user_roles,
+                },
+            )
+        else:
+            self._update_relation_data(event.relation.id, {"database": self.database})
+
+    def _on_relation_changed_event(self, event: RelationChangedEvent) -> None:
+        """Event emitted when the database relation has changed."""
+        # Check which data has changed to emit customs events.
+        diff = self._diff(event)
+
+        # Check if the database is created
+        # (the database charm shared the credentials).
+        if "username" in diff.added and "password" in diff.added:
+            # Emit the default event (the one without an alias).
+            logger.info("database created at %s", datetime.now())
+            self.on.database_created.emit(event.relation, app=event.app, unit=event.unit)
+
+            # Emit the aliased event (if any).
+            self._emit_aliased_event(event, "database_created")
+
+            # To avoid unnecessary application restarts do not trigger
+            # “endpoints_changed“ event if “database_created“ is triggered.
+            return
+
+        # Emit an endpoints changed event if the database
+        # added or changed this info in the relation databag.
+        if "endpoints" in diff.added or "endpoints" in diff.changed:
+            # Emit the default event (the one without an alias).
+            logger.info("endpoints changed on %s", datetime.now())
+            self.on.endpoints_changed.emit(event.relation, app=event.app, unit=event.unit)
+
+            # Emit the aliased event (if any).
+            self._emit_aliased_event(event, "endpoints_changed")
+
+            # To avoid unnecessary application restarts do not trigger
+            # “read_only_endpoints_changed“ event if “endpoints_changed“ is triggered.
+            return
+
+        # Emit a read only endpoints changed event if the database
+        # added or changed this info in the relation databag.
+        if "read-only-endpoints" in diff.added or "read-only-endpoints" in diff.changed:
+            # Emit the default event (the one without an alias).
+            logger.info("read-only-endpoints changed on %s", datetime.now())
+            self.on.read_only_endpoints_changed.emit(
+                event.relation, app=event.app, unit=event.unit
+            )
+
+            # Emit the aliased event (if any).
+            self._emit_aliased_event(event, "read_only_endpoints_changed")
+
+
+# Kafka related events
+
+
+class KafkaProvidesEvent(RelationEvent):
+    """Base class for Kafka events."""
+
+    @property
+    def topic(self) -> Optional[str]:
+        """Returns the topic that was requested."""
+        return self.relation.data[self.relation.app].get("topic")
+
+
+class TopicRequestedEvent(KafkaProvidesEvent, ExtraRoleEvent):
+    """Event emitted when a new topic is requested for use on this relation."""
+
+
+class KafkaProvidesEvents(CharmEvents):
+    """Kafka events.
+
+    This class defines the events that the Kafka can emit.
+    """
+
+    topic_requested = EventSource(TopicRequestedEvent)
+
+
+class KafkaRequiresEvent(RelationEvent):
+    """Base class for Kafka events."""
+
+    @property
+    def bootstrap_server(self) -> Optional[str]:
+        """Returns a a comma-seperated list of broker uris."""
+        return self.relation.data[self.relation.app].get("endpoints")
+
+    @property
+    def consumer_group_prefix(self) -> Optional[str]:
+        """Returns the consumer-group-prefix."""
+        return self.relation.data[self.relation.app].get("consumer-group-prefix")
+
+    @property
+    def zookeeper_uris(self) -> Optional[str]:
+        """Returns a comma separated list of Zookeeper uris."""
+        return self.relation.data[self.relation.app].get("zookeeper-uris")
+
+
+class TopicCreatedEvent(AuthenticationEvent, KafkaRequiresEvent):
+    """Event emitted when a new topic is created for use on this relation."""
+
+
+class BootstrapServerChangedEvent(AuthenticationEvent, KafkaRequiresEvent):
+    """Event emitted when the bootstrap server is changed."""
+
+
+class KafkaRequiresEvents(CharmEvents):
+    """Kafka events.
+
+    This class defines the events that the Kafka can emit.
+    """
+
+    topic_created = EventSource(TopicCreatedEvent)
+    bootstrap_server_changed = EventSource(BootstrapServerChangedEvent)
+
+
+# Kafka Provides and Requires
+
+
+class KafkaProvides(DataProvides):
+    """Provider-side of the Kafka relation."""
+
+    on = KafkaProvidesEvents()
+
+    def __init__(self, charm: CharmBase, relation_name: str) -> None:
+        super().__init__(charm, relation_name)
+
+    def _on_relation_changed(self, event: RelationChangedEvent) -> None:
+        """Event emitted when the relation has changed."""
+        # Only the leader should handle this event.
+        if not self.local_unit.is_leader():
+            return
+
+        # Check which data has changed to emit customs events.
+        diff = self._diff(event)
+
+        # Emit a topic requested event if the setup key (topic name and optional
+        # extra user roles) was added to the relation databag by the application.
+        if "topic" in diff.added:
+            self.on.topic_requested.emit(event.relation, app=event.app, unit=event.unit)
+
+    def set_bootstrap_server(self, relation_id: int, bootstrap_server: str) -> None:
+        """Set the bootstrap server in the application relation databag.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            bootstrap_server: the bootstrap server address.
+        """
+        self._update_relation_data(relation_id, {"endpoints": bootstrap_server})
+
+    def set_consumer_group_prefix(self, relation_id: int, consumer_group_prefix: str) -> None:
+        """Set the consumer group prefix in the application relation databag.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            consumer_group_prefix: the consumer group prefix string.
+        """
+        self._update_relation_data(relation_id, {"consumer-group-prefix": consumer_group_prefix})
+
+    def set_zookeeper_uris(self, relation_id: int, zookeeper_uris: str) -> None:
+        """Set the zookeeper uris in the application relation databag.
+
+        Args:
+            relation_id: the identifier for a particular relation.
+            zookeeper_uris: comma-seperated list of ZooKeeper server uris.
+        """
+        self._update_relation_data(relation_id, {"zookeeper-uris": zookeeper_uris})
+
+
+class KafkaRequires(DataRequires):
+    """Requires-side of the Kafka relation."""
+
+    on = KafkaRequiresEvents()
+
+    def __init__(self, charm, relation_name: str, topic: str, extra_user_roles: str = None):
+        """Manager of Kafka client relations."""
+        # super().__init__(charm, relation_name)
+        super().__init__(charm, relation_name, extra_user_roles)
+        self.charm = charm
+        self.topic = topic
+
+    def _on_relation_joined_event(self, event: RelationJoinedEvent) -> None:
+        """Event emitted when the application joins the Kafka relation."""
+        # Sets both topic and extra user roles in the relation
+        # if the roles are provided. Otherwise, sets only the topic.
+        self._update_relation_data(
+            event.relation.id,
+            {
+                "topic": self.topic,
+                "extra-user-roles": self.extra_user_roles,
+            }
+            if self.extra_user_roles is not None
+            else {"topic": self.topic},
+        )
+
+    def _on_relation_changed_event(self, event: RelationChangedEvent) -> None:
+        """Event emitted when the Kafka relation has changed."""
+        # Check which data has changed to emit customs events.
+        diff = self._diff(event)
+
+        # Check if the topic is created
+        # (the Kafka charm shared the credentials).
+        if "username" in diff.added and "password" in diff.added:
+            # Emit the default event (the one without an alias).
+            logger.info("topic created at %s", datetime.now())
+            self.on.topic_created.emit(event.relation, app=event.app, unit=event.unit)
+
+            # To avoid unnecessary application restarts do not trigger
+            # “endpoints_changed“ event if “topic_created“ is triggered.
+            return
+
+        # Emit an endpoints (bootstap-server) changed event if the Kakfa endpoints
+        # added or changed this info in the relation databag.
+        if "endpoints" in diff.added or "endpoints" in diff.changed:
+            # Emit the default event (the one without an alias).
+            logger.info("endpoints changed on %s", datetime.now())
+            self.on.bootstrap_server_changed.emit(
+                event.relation, app=event.app, unit=event.unit
+            )  # here check if this is the right design
+            return
diff --git a/installers/charm/osm-ro/lib/charms/kafka_k8s/v0/kafka.py b/installers/charm/osm-ro/lib/charms/kafka_k8s/v0/kafka.py
new file mode 100644
index 0000000..aeb5edc
--- /dev/null
+++ b/installers/charm/osm-ro/lib/charms/kafka_k8s/v0/kafka.py
@@ -0,0 +1,200 @@
+# Copyright 2022 Canonical Ltd.
+# See LICENSE file for licensing details.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Kafka library.
+
+This [library](https://juju.is/docs/sdk/libraries) implements both sides of the
+`kafka` [interface](https://juju.is/docs/sdk/relations).
+
+The *provider* side of this interface is implemented by the
+[kafka-k8s Charmed Operator](https://charmhub.io/kafka-k8s).
+
+Any Charmed Operator that *requires* Kafka for providing its
+service should implement the *requirer* side of this interface.
+
+In a nutshell using this library to implement a Charmed Operator *requiring*
+Kafka would look like
+
+```
+$ charmcraft fetch-lib charms.kafka_k8s.v0.kafka
+```
+
+`metadata.yaml`:
+
+```
+requires:
+  kafka:
+    interface: kafka
+    limit: 1
+```
+
+`src/charm.py`:
+
+```
+from charms.kafka_k8s.v0.kafka import KafkaEvents, KafkaRequires
+from ops.charm import CharmBase
+
+
+class MyCharm(CharmBase):
+
+    on = KafkaEvents()
+
+    def __init__(self, *args):
+        super().__init__(*args)
+        self.kafka = KafkaRequires(self)
+        self.framework.observe(
+            self.on.kafka_available,
+            self._on_kafka_available,
+        )
+        self.framework.observe(
+            self.on["kafka"].relation_broken,
+            self._on_kafka_broken,
+        )
+
+    def _on_kafka_available(self, event):
+        # Get Kafka host and port
+        host: str = self.kafka.host
+        port: int = self.kafka.port
+        # host => "kafka-k8s"
+        # port => 9092
+
+    def _on_kafka_broken(self, event):
+        # Stop service
+        # ...
+        self.unit.status = BlockedStatus("need kafka relation")
+```
+
+You can file bugs
+[here](https://github.com/charmed-osm/kafka-k8s-operator/issues)!
+"""
+
+from typing import Optional
+
+from ops.charm import CharmBase, CharmEvents
+from ops.framework import EventBase, EventSource, Object
+
+# The unique Charmhub library identifier, never change it
+from ops.model import Relation
+
+LIBID = "eacc8c85082347c9aae740e0220b8376"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 4
+
+
+KAFKA_HOST_APP_KEY = "host"
+KAFKA_PORT_APP_KEY = "port"
+
+
+class _KafkaAvailableEvent(EventBase):
+    """Event emitted when Kafka is available."""
+
+
+class KafkaEvents(CharmEvents):
+    """Kafka events.
+
+    This class defines the events that Kafka can emit.
+
+    Events:
+        kafka_available (_KafkaAvailableEvent)
+    """
+
+    kafka_available = EventSource(_KafkaAvailableEvent)
+
+
+class KafkaRequires(Object):
+    """Requires-side of the Kafka relation."""
+
+    def __init__(self, charm: CharmBase, endpoint_name: str = "kafka") -> None:
+        super().__init__(charm, endpoint_name)
+        self.charm = charm
+        self._endpoint_name = endpoint_name
+
+        # Observe relation events
+        event_observe_mapping = {
+            charm.on[self._endpoint_name].relation_changed: self._on_relation_changed,
+        }
+        for event, observer in event_observe_mapping.items():
+            self.framework.observe(event, observer)
+
+    def _on_relation_changed(self, event) -> None:
+        if event.relation.app and all(
+            key in event.relation.data[event.relation.app]
+            for key in (KAFKA_HOST_APP_KEY, KAFKA_PORT_APP_KEY)
+        ):
+            self.charm.on.kafka_available.emit()
+
+    @property
+    def host(self) -> str:
+        """Get kafka hostname."""
+        relation: Relation = self.model.get_relation(self._endpoint_name)
+        return (
+            relation.data[relation.app].get(KAFKA_HOST_APP_KEY)
+            if relation and relation.app
+            else None
+        )
+
+    @property
+    def port(self) -> int:
+        """Get kafka port number."""
+        relation: Relation = self.model.get_relation(self._endpoint_name)
+        return (
+            int(relation.data[relation.app].get(KAFKA_PORT_APP_KEY))
+            if relation and relation.app
+            else None
+        )
+
+
+class KafkaProvides(Object):
+    """Provides-side of the Kafka relation."""
+
+    def __init__(self, charm: CharmBase, endpoint_name: str = "kafka") -> None:
+        super().__init__(charm, endpoint_name)
+        self._endpoint_name = endpoint_name
+
+    def set_host_info(self, host: str, port: int, relation: Optional[Relation] = None) -> None:
+        """Set Kafka host and port.
+
+        This function writes in the application data of the relation, therefore,
+        only the unit leader can call it.
+
+        Args:
+            host (str): Kafka hostname or IP address.
+            port (int): Kafka port.
+            relation (Optional[Relation]): Relation to update.
+                                           If not specified, all relations will be updated.
+
+        Raises:
+            Exception: if a non-leader unit calls this function.
+        """
+        if not self.model.unit.is_leader():
+            raise Exception("only the leader set host information.")
+
+        if relation:
+            self._update_relation_data(host, port, relation)
+            return
+
+        for relation in self.model.relations[self._endpoint_name]:
+            self._update_relation_data(host, port, relation)
+
+    def _update_relation_data(self, host: str, port: int, relation: Relation) -> None:
+        """Update data in relation if needed."""
+        relation.data[self.model.app][KAFKA_HOST_APP_KEY] = host
+        relation.data[self.model.app][KAFKA_PORT_APP_KEY] = str(port)
diff --git a/installers/charm/osm-ro/lib/charms/observability_libs/v1/kubernetes_service_patch.py b/installers/charm/osm-ro/lib/charms/observability_libs/v1/kubernetes_service_patch.py
new file mode 100644
index 0000000..506dbf0
--- /dev/null
+++ b/installers/charm/osm-ro/lib/charms/observability_libs/v1/kubernetes_service_patch.py
@@ -0,0 +1,291 @@
+# Copyright 2021 Canonical Ltd.
+# See LICENSE file for licensing details.
+#   http://www.apache.org/licenses/LICENSE-2.0
+
+"""# KubernetesServicePatch Library.
+
+This library is designed to enable developers to more simply patch the Kubernetes Service created
+by Juju during the deployment of a sidecar charm. When sidecar charms are deployed, Juju creates a
+service named after the application in the namespace (named after the Juju model). This service by
+default contains a "placeholder" port, which is 65536/TCP.
+
+When modifying the default set of resources managed by Juju, one must consider the lifecycle of the
+charm. In this case, any modifications to the default service (created during deployment), will be
+overwritten during a charm upgrade.
+
+When initialised, this library binds a handler to the parent charm's `install` and `upgrade_charm`
+events which applies the patch to the cluster. This should ensure that the service ports are
+correct throughout the charm's life.
+
+The constructor simply takes a reference to the parent charm, and a list of
+[`lightkube`](https://github.com/gtsystem/lightkube) ServicePorts that each define a port for the
+service. For information regarding the `lightkube` `ServicePort` model, please visit the
+`lightkube` [docs](https://gtsystem.github.io/lightkube-models/1.23/models/core_v1/#serviceport).
+
+Optionally, a name of the service (in case service name needs to be patched as well), labels,
+selectors, and annotations can be provided as keyword arguments.
+
+## Getting Started
+
+To get started using the library, you just need to fetch the library using `charmcraft`. **Note
+that you also need to add `lightkube` and `lightkube-models` to your charm's `requirements.txt`.**
+
+```shell
+cd some-charm
+charmcraft fetch-lib charms.observability_libs.v0.kubernetes_service_patch
+echo <<-EOF >> requirements.txt
+lightkube
+lightkube-models
+EOF
+```
+
+Then, to initialise the library:
+
+For `ClusterIP` services:
+
+```python
+# ...
+from charms.observability_libs.v0.kubernetes_service_patch import KubernetesServicePatch
+from lightkube.models.core_v1 import ServicePort
+
+class SomeCharm(CharmBase):
+  def __init__(self, *args):
+    # ...
+    port = ServicePort(443, name=f"{self.app.name}")
+    self.service_patcher = KubernetesServicePatch(self, [port])
+    # ...
+```
+
+For `LoadBalancer`/`NodePort` services:
+
+```python
+# ...
+from charms.observability_libs.v0.kubernetes_service_patch import KubernetesServicePatch
+from lightkube.models.core_v1 import ServicePort
+
+class SomeCharm(CharmBase):
+  def __init__(self, *args):
+    # ...
+    port = ServicePort(443, name=f"{self.app.name}", targetPort=443, nodePort=30666)
+    self.service_patcher = KubernetesServicePatch(
+        self, [port], "LoadBalancer"
+    )
+    # ...
+```
+
+Port protocols can also be specified. Valid protocols are `"TCP"`, `"UDP"`, and `"SCTP"`
+
+```python
+# ...
+from charms.observability_libs.v0.kubernetes_service_patch import KubernetesServicePatch
+from lightkube.models.core_v1 import ServicePort
+
+class SomeCharm(CharmBase):
+  def __init__(self, *args):
+    # ...
+    tcp = ServicePort(443, name=f"{self.app.name}-tcp", protocol="TCP")
+    udp = ServicePort(443, name=f"{self.app.name}-udp", protocol="UDP")
+    sctp = ServicePort(443, name=f"{self.app.name}-sctp", protocol="SCTP")
+    self.service_patcher = KubernetesServicePatch(self, [tcp, udp, sctp])
+    # ...
+```
+
+Additionally, you may wish to use mocks in your charm's unit testing to ensure that the library
+does not try to make any API calls, or open any files during testing that are unlikely to be
+present, and could break your tests. The easiest way to do this is during your test `setUp`:
+
+```python
+# ...
+
+@patch("charm.KubernetesServicePatch", lambda x, y: None)
+def setUp(self, *unused):
+    self.harness = Harness(SomeCharm)
+    # ...
+```
+"""
+
+import logging
+from types import MethodType
+from typing import List, Literal
+
+from lightkube import ApiError, Client
+from lightkube.models.core_v1 import ServicePort, ServiceSpec
+from lightkube.models.meta_v1 import ObjectMeta
+from lightkube.resources.core_v1 import Service
+from lightkube.types import PatchType
+from ops.charm import CharmBase
+from ops.framework import Object
+
+logger = logging.getLogger(__name__)
+
+# The unique Charmhub library identifier, never change it
+LIBID = "0042f86d0a874435adef581806cddbbb"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 1
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 1
+
+ServiceType = Literal["ClusterIP", "LoadBalancer"]
+
+
+class KubernetesServicePatch(Object):
+    """A utility for patching the Kubernetes service set up by Juju."""
+
+    def __init__(
+        self,
+        charm: CharmBase,
+        ports: List[ServicePort],
+        service_name: str = None,
+        service_type: ServiceType = "ClusterIP",
+        additional_labels: dict = None,
+        additional_selectors: dict = None,
+        additional_annotations: dict = None,
+    ):
+        """Constructor for KubernetesServicePatch.
+
+        Args:
+            charm: the charm that is instantiating the library.
+            ports: a list of ServicePorts
+            service_name: allows setting custom name to the patched service. If none given,
+                application name will be used.
+            service_type: desired type of K8s service. Default value is in line with ServiceSpec's
+                default value.
+            additional_labels: Labels to be added to the kubernetes service (by default only
+                "app.kubernetes.io/name" is set to the service name)
+            additional_selectors: Selectors to be added to the kubernetes service (by default only
+                "app.kubernetes.io/name" is set to the service name)
+            additional_annotations: Annotations to be added to the kubernetes service.
+        """
+        super().__init__(charm, "kubernetes-service-patch")
+        self.charm = charm
+        self.service_name = service_name if service_name else self._app
+        self.service = self._service_object(
+            ports,
+            service_name,
+            service_type,
+            additional_labels,
+            additional_selectors,
+            additional_annotations,
+        )
+
+        # Make mypy type checking happy that self._patch is a method
+        assert isinstance(self._patch, MethodType)
+        # Ensure this patch is applied during the 'install' and 'upgrade-charm' events
+        self.framework.observe(charm.on.install, self._patch)
+        self.framework.observe(charm.on.upgrade_charm, self._patch)
+
+    def _service_object(
+        self,
+        ports: List[ServicePort],
+        service_name: str = None,
+        service_type: ServiceType = "ClusterIP",
+        additional_labels: dict = None,
+        additional_selectors: dict = None,
+        additional_annotations: dict = None,
+    ) -> Service:
+        """Creates a valid Service representation.
+
+        Args:
+            ports: a list of ServicePorts
+            service_name: allows setting custom name to the patched service. If none given,
+                application name will be used.
+            service_type: desired type of K8s service. Default value is in line with ServiceSpec's
+                default value.
+            additional_labels: Labels to be added to the kubernetes service (by default only
+                "app.kubernetes.io/name" is set to the service name)
+            additional_selectors: Selectors to be added to the kubernetes service (by default only
+                "app.kubernetes.io/name" is set to the service name)
+            additional_annotations: Annotations to be added to the kubernetes service.
+
+        Returns:
+            Service: A valid representation of a Kubernetes Service with the correct ports.
+        """
+        if not service_name:
+            service_name = self._app
+        labels = {"app.kubernetes.io/name": self._app}
+        if additional_labels:
+            labels.update(additional_labels)
+        selector = {"app.kubernetes.io/name": self._app}
+        if additional_selectors:
+            selector.update(additional_selectors)
+        return Service(
+            apiVersion="v1",
+            kind="Service",
+            metadata=ObjectMeta(
+                namespace=self._namespace,
+                name=service_name,
+                labels=labels,
+                annotations=additional_annotations,  # type: ignore[arg-type]
+            ),
+            spec=ServiceSpec(
+                selector=selector,
+                ports=ports,
+                type=service_type,
+            ),
+        )
+
+    def _patch(self, _) -> None:
+        """Patch the Kubernetes service created by Juju to map the correct port.
+
+        Raises:
+            PatchFailed: if patching fails due to lack of permissions, or otherwise.
+        """
+        if not self.charm.unit.is_leader():
+            return
+
+        client = Client()
+        try:
+            if self.service_name != self._app:
+                self._delete_and_create_service(client)
+            client.patch(Service, self.service_name, self.service, patch_type=PatchType.MERGE)
+        except ApiError as e:
+            if e.status.code == 403:
+                logger.error("Kubernetes service patch failed: `juju trust` this application.")
+            else:
+                logger.error("Kubernetes service patch failed: %s", str(e))
+        else:
+            logger.info("Kubernetes service '%s' patched successfully", self._app)
+
+    def _delete_and_create_service(self, client: Client):
+        service = client.get(Service, self._app, namespace=self._namespace)
+        service.metadata.name = self.service_name  # type: ignore[attr-defined]
+        service.metadata.resourceVersion = service.metadata.uid = None  # type: ignore[attr-defined]   # noqa: E501
+        client.delete(Service, self._app, namespace=self._namespace)
+        client.create(service)
+
+    def is_patched(self) -> bool:
+        """Reports if the service patch has been applied.
+
+        Returns:
+            bool: A boolean indicating if the service patch has been applied.
+        """
+        client = Client()
+        # Get the relevant service from the cluster
+        service = client.get(Service, name=self.service_name, namespace=self._namespace)
+        # Construct a list of expected ports, should the patch be applied
+        expected_ports = [(p.port, p.targetPort) for p in self.service.spec.ports]
+        # Construct a list in the same manner, using the fetched service
+        fetched_ports = [(p.port, p.targetPort) for p in service.spec.ports]  # type: ignore[attr-defined]  # noqa: E501
+        return expected_ports == fetched_ports
+
+    @property
+    def _app(self) -> str:
+        """Name of the current Juju application.
+
+        Returns:
+            str: A string containing the name of the current Juju application.
+        """
+        return self.charm.app.name
+
+    @property
+    def _namespace(self) -> str:
+        """The Kubernetes namespace we're running in.
+
+        Returns:
+            str: A string containing the name of the current Kubernetes namespace.
+        """
+        with open("/var/run/secrets/kubernetes.io/serviceaccount/namespace", "r") as f:
+            return f.read().strip()
diff --git a/installers/charm/osm-ro/lib/charms/osm_libs/v0/utils.py b/installers/charm/osm-ro/lib/charms/osm_libs/v0/utils.py
new file mode 100644
index 0000000..d739ba6
--- /dev/null
+++ b/installers/charm/osm-ro/lib/charms/osm_libs/v0/utils.py
@@ -0,0 +1,544 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+# See LICENSE file for licensing details.
+#         http://www.apache.org/licenses/LICENSE-2.0
+"""OSM Utils Library.
+
+This library offers some utilities made for but not limited to Charmed OSM.
+
+# Getting started
+
+Execute the following command inside your Charmed Operator folder to fetch the library.
+
+```shell
+charmcraft fetch-lib charms.osm_libs.v0.utils
+```
+
+# CharmError Exception
+
+An exception that takes to arguments, the message and the StatusBase class, which are useful
+to set the status of the charm when the exception raises.
+
+Example:
+```shell
+from charms.osm_libs.v0.utils import CharmError
+
+class MyCharm(CharmBase):
+    def _on_config_changed(self, _):
+        try:
+            if not self.config.get("some-option"):
+                raise CharmError("need some-option", BlockedStatus)
+
+            if not self.mysql_ready:
+                raise CharmError("waiting for mysql", WaitingStatus)
+
+            # Do stuff...
+
+        exception CharmError as e:
+            self.unit.status = e.status
+```
+
+# Pebble validations
+
+The `check_container_ready` function checks that a container is ready,
+and therefore Pebble is ready.
+
+The `check_service_active` function checks that a service in a container is running.
+
+Both functions raise a CharmError if the validations fail.
+
+Example:
+```shell
+from charms.osm_libs.v0.utils import check_container_ready, check_service_active
+
+class MyCharm(CharmBase):
+    def _on_config_changed(self, _):
+        try:
+            container: Container = self.unit.get_container("my-container")
+            check_container_ready(container)
+            check_service_active(container, "my-service")
+            # Do stuff...
+
+        exception CharmError as e:
+            self.unit.status = e.status
+```
+
+# Debug-mode
+
+The debug-mode allows OSM developers to easily debug OSM modules.
+
+Example:
+```shell
+from charms.osm_libs.v0.utils import DebugMode
+
+class MyCharm(CharmBase):
+    _stored = StoredState()
+
+    def __init__(self, _):
+        # ...
+        container: Container = self.unit.get_container("my-container")
+        hostpaths = [
+            HostPath(
+                config="module-hostpath",
+                container_path="/usr/lib/python3/dist-packages/module"
+            ),
+        ]
+        vscode_workspace_path = "files/vscode-workspace.json"
+        self.debug_mode = DebugMode(
+            self,
+            self._stored,
+            container,
+            hostpaths,
+            vscode_workspace_path,
+        )
+
+    def _on_update_status(self, _):
+        if self.debug_mode.started:
+            return
+        # ...
+
+    def _get_debug_mode_information(self):
+        command = self.debug_mode.command
+        password = self.debug_mode.password
+        return command, password
+```
+
+# More
+
+- Get pod IP with `get_pod_ip()`
+"""
+from dataclasses import dataclass
+import logging
+import secrets
+import socket
+from pathlib import Path
+from typing import List
+
+from lightkube import Client
+from lightkube.models.core_v1 import HostPathVolumeSource, Volume, VolumeMount
+from lightkube.resources.apps_v1 import StatefulSet
+from ops.charm import CharmBase
+from ops.framework import Object, StoredState
+from ops.model import (
+    ActiveStatus,
+    BlockedStatus,
+    Container,
+    MaintenanceStatus,
+    StatusBase,
+    WaitingStatus,
+)
+from ops.pebble import ServiceStatus
+
+# The unique Charmhub library identifier, never change it
+LIBID = "e915908eebee4cdd972d484728adf984"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 5
+
+logger = logging.getLogger(__name__)
+
+
+class CharmError(Exception):
+    """Charm Error Exception."""
+
+    def __init__(self, message: str, status_class: StatusBase = BlockedStatus) -> None:
+        self.message = message
+        self.status_class = status_class
+        self.status = status_class(message)
+
+
+def check_container_ready(container: Container) -> None:
+    """Check Pebble has started in the container.
+
+    Args:
+        container (Container): Container to be checked.
+
+    Raises:
+        CharmError: if container is not ready.
+    """
+    if not container.can_connect():
+        raise CharmError("waiting for pebble to start", MaintenanceStatus)
+
+
+def check_service_active(container: Container, service_name: str) -> None:
+    """Check if the service is running.
+
+    Args:
+        container (Container): Container to be checked.
+        service_name (str): Name of the service to check.
+
+    Raises:
+        CharmError: if the service is not running.
+    """
+    if service_name not in container.get_plan().services:
+        raise CharmError(f"{service_name} service not configured yet", WaitingStatus)
+
+    if container.get_service(service_name).current != ServiceStatus.ACTIVE:
+        raise CharmError(f"{service_name} service is not running")
+
+
+def get_pod_ip() -> str:
+    """Get Kubernetes Pod IP.
+
+    Returns:
+        str: The IP of the Pod.
+    """
+    return socket.gethostbyname(socket.gethostname())
+
+
+_DEBUG_SCRIPT = r"""#!/bin/bash
+# Install SSH
+
+function download_code(){{
+    wget https://go.microsoft.com/fwlink/?LinkID=760868 -O code.deb
+}}
+
+function setup_envs(){{
+    grep "source /debug.envs" /root/.bashrc || echo "source /debug.envs" | tee -a /root/.bashrc
+}}
+function setup_ssh(){{
+    apt install ssh -y
+    cat /etc/ssh/sshd_config |
+        grep -E '^PermitRootLogin yes$$' || (
+        echo PermitRootLogin yes |
+        tee -a /etc/ssh/sshd_config
+    )
+    service ssh stop
+    sleep 3
+    service ssh start
+    usermod --password $(echo {} | openssl passwd -1 -stdin) root
+}}
+
+function setup_code(){{
+    apt install libasound2 -y
+    (dpkg -i code.deb || apt-get install -f -y || apt-get install -f -y) && echo Code installed successfully
+    code --install-extension ms-python.python --user-data-dir /root
+    mkdir -p /root/.vscode-server
+    cp -R /root/.vscode/extensions /root/.vscode-server/extensions
+}}
+
+export DEBIAN_FRONTEND=noninteractive
+apt update && apt install wget -y
+download_code &
+setup_ssh &
+setup_envs
+wait
+setup_code &
+wait
+"""
+
+
+@dataclass
+class SubModule:
+    """Represent RO Submodules."""
+    sub_module_path: str
+    container_path: str
+
+
+class HostPath:
+    """Represents a hostpath."""
+    def __init__(self, config: str, container_path: str, submodules: dict = None) -> None:
+        mount_path_items = config.split("-")
+        mount_path_items.reverse()
+        self.mount_path = "/" + "/".join(mount_path_items)
+        self.config = config
+        self.sub_module_dict = {}
+        if submodules:
+            for submodule in submodules.keys():
+                self.sub_module_dict[submodule] = SubModule(
+                    sub_module_path=self.mount_path + "/" + submodule + "/" + submodules[submodule].split("/")[-1],
+                    container_path=submodules[submodule],
+                )
+        else:
+            self.container_path = container_path
+            self.module_name = container_path.split("/")[-1]
+
+class DebugMode(Object):
+    """Class to handle the debug-mode."""
+
+    def __init__(
+        self,
+        charm: CharmBase,
+        stored: StoredState,
+        container: Container,
+        hostpaths: List[HostPath] = [],
+        vscode_workspace_path: str = "files/vscode-workspace.json",
+    ) -> None:
+        super().__init__(charm, "debug-mode")
+
+        self.charm = charm
+        self._stored = stored
+        self.hostpaths = hostpaths
+        self.vscode_workspace = Path(vscode_workspace_path).read_text()
+        self.container = container
+
+        self._stored.set_default(
+            debug_mode_started=False,
+            debug_mode_vscode_command=None,
+            debug_mode_password=None,
+        )
+
+        self.framework.observe(self.charm.on.config_changed, self._on_config_changed)
+        self.framework.observe(self.charm.on[container.name].pebble_ready, self._on_config_changed)
+        self.framework.observe(self.charm.on.update_status, self._on_update_status)
+
+    def _on_config_changed(self, _) -> None:
+        """Handler for the config-changed event."""
+        if not self.charm.unit.is_leader():
+            return
+
+        debug_mode_enabled = self.charm.config.get("debug-mode", False)
+        action = self.enable if debug_mode_enabled else self.disable
+        action()
+
+    def _on_update_status(self, _) -> None:
+        """Handler for the update-status event."""
+        if not self.charm.unit.is_leader() or not self.started:
+            return
+
+        self.charm.unit.status = ActiveStatus("debug-mode: ready")
+
+    @property
+    def started(self) -> bool:
+        """Indicates whether the debug-mode has started or not."""
+        return self._stored.debug_mode_started
+
+    @property
+    def command(self) -> str:
+        """Command to launch vscode."""
+        return self._stored.debug_mode_vscode_command
+
+    @property
+    def password(self) -> str:
+        """SSH password."""
+        return self._stored.debug_mode_password
+
+    def enable(self, service_name: str = None) -> None:
+        """Enable debug-mode.
+
+        This function mounts hostpaths of the OSM modules (if set), and
+        configures the container so it can be easily debugged. The setup
+        includes the configuration of SSH, environment variables, and
+        VSCode workspace and plugins.
+
+        Args:
+            service_name (str, optional): Pebble service name which has the desired environment
+                variables. Mandatory if there is more than one Pebble service configured.
+        """
+        hostpaths_to_reconfigure = self._hostpaths_to_reconfigure()
+        if self.started and not hostpaths_to_reconfigure:
+            self.charm.unit.status = ActiveStatus("debug-mode: ready")
+            return
+
+        logger.debug("enabling debug-mode")
+
+        # Mount hostpaths if set.
+        # If hostpaths are mounted, the statefulset will be restarted,
+        # and for that reason we return immediately. On restart, the hostpaths
+        # won't be mounted and then we can continue and setup the debug-mode.
+        if hostpaths_to_reconfigure:
+            self.charm.unit.status = MaintenanceStatus("debug-mode: configuring hostpaths")
+            self._configure_hostpaths(hostpaths_to_reconfigure)
+            return
+
+        self.charm.unit.status = MaintenanceStatus("debug-mode: starting")
+        password = secrets.token_hex(8)
+        self._setup_debug_mode(
+            password,
+            service_name,
+            mounted_hostpaths=[hp for hp in self.hostpaths if self.charm.config.get(hp.config)],
+        )
+
+        self._stored.debug_mode_vscode_command = self._get_vscode_command(get_pod_ip())
+        self._stored.debug_mode_password = password
+        self._stored.debug_mode_started = True
+        logger.info("debug-mode is ready")
+        self.charm.unit.status = ActiveStatus("debug-mode: ready")
+
+    def disable(self) -> None:
+        """Disable debug-mode."""
+        logger.debug("disabling debug-mode")
+        current_status = self.charm.unit.status
+        hostpaths_unmounted = self._unmount_hostpaths()
+
+        if not self._stored.debug_mode_started:
+            return
+        self._stored.debug_mode_started = False
+        self._stored.debug_mode_vscode_command = None
+        self._stored.debug_mode_password = None
+
+        if not hostpaths_unmounted:
+            self.charm.unit.status = current_status
+            self._restart()
+
+    def _hostpaths_to_reconfigure(self) -> List[HostPath]:
+        hostpaths_to_reconfigure: List[HostPath] = []
+        client = Client()
+        statefulset = client.get(StatefulSet, self.charm.app.name, namespace=self.charm.model.name)
+        volumes = statefulset.spec.template.spec.volumes
+
+        for hostpath in self.hostpaths:
+            hostpath_is_set = True if self.charm.config.get(hostpath.config) else False
+            hostpath_already_configured = next(
+                (True for volume in volumes if volume.name == hostpath.config), False
+            )
+            if hostpath_is_set != hostpath_already_configured:
+                hostpaths_to_reconfigure.append(hostpath)
+
+        return hostpaths_to_reconfigure
+
+    def _setup_debug_mode(
+        self,
+        password: str,
+        service_name: str = None,
+        mounted_hostpaths: List[HostPath] = [],
+    ) -> None:
+        services = self.container.get_plan().services
+        if not service_name and len(services) != 1:
+            raise Exception("Cannot start debug-mode: please set the service_name")
+
+        service = None
+        if not service_name:
+            service_name, service = services.popitem()
+        if not service:
+            service = services.get(service_name)
+
+        logger.debug(f"getting environment variables from service {service_name}")
+        environment = service.environment
+        environment_file_content = "\n".join(
+            [f'export {key}="{value}"' for key, value in environment.items()]
+        )
+        logger.debug(f"pushing environment file to {self.container.name} container")
+        self.container.push("/debug.envs", environment_file_content)
+
+        # Push VSCode workspace
+        logger.debug(f"pushing vscode workspace to {self.container.name} container")
+        self.container.push("/debug.code-workspace", self.vscode_workspace)
+
+        # Execute debugging script
+        logger.debug(f"pushing debug-mode setup script to {self.container.name} container")
+        self.container.push("/debug.sh", _DEBUG_SCRIPT.format(password), permissions=0o777)
+        logger.debug(f"executing debug-mode setup script in {self.container.name} container")
+        self.container.exec(["/debug.sh"]).wait_output()
+        logger.debug(f"stopping service {service_name} in {self.container.name} container")
+        self.container.stop(service_name)
+
+        # Add symlinks to mounted hostpaths
+        for hostpath in mounted_hostpaths:
+            logger.debug(f"adding symlink for {hostpath.config}")
+            if len(hostpath.sub_module_dict) > 0:
+                for sub_module in hostpath.sub_module_dict.keys():
+                    self.container.exec(["rm", "-rf", hostpath.sub_module_dict[sub_module].container_path]).wait_output()
+                    self.container.exec(
+                        [
+                            "ln",
+                            "-s",
+                            hostpath.sub_module_dict[sub_module].sub_module_path,
+                            hostpath.sub_module_dict[sub_module].container_path,
+                        ]
+                    )
+
+            else:
+                self.container.exec(["rm", "-rf", hostpath.container_path]).wait_output()
+                self.container.exec(
+                    [
+                        "ln",
+                        "-s",
+                        f"{hostpath.mount_path}/{hostpath.module_name}",
+                        hostpath.container_path,
+                    ]
+                )
+
+    def _configure_hostpaths(self, hostpaths: List[HostPath]):
+        client = Client()
+        statefulset = client.get(StatefulSet, self.charm.app.name, namespace=self.charm.model.name)
+
+        for hostpath in hostpaths:
+            if self.charm.config.get(hostpath.config):
+                self._add_hostpath_to_statefulset(hostpath, statefulset)
+            else:
+                self._delete_hostpath_from_statefulset(hostpath, statefulset)
+
+        client.replace(statefulset)
+
+    def _unmount_hostpaths(self) -> bool:
+        client = Client()
+        hostpath_unmounted = False
+        statefulset = client.get(StatefulSet, self.charm.app.name, namespace=self.charm.model.name)
+
+        for hostpath in self.hostpaths:
+            if self._delete_hostpath_from_statefulset(hostpath, statefulset):
+                hostpath_unmounted = True
+
+        if hostpath_unmounted:
+            client.replace(statefulset)
+
+        return hostpath_unmounted
+
+    def _add_hostpath_to_statefulset(self, hostpath: HostPath, statefulset: StatefulSet):
+        # Add volume
+        logger.debug(f"adding volume {hostpath.config} to {self.charm.app.name} statefulset")
+        volume = Volume(
+            hostpath.config,
+            hostPath=HostPathVolumeSource(
+                path=self.charm.config[hostpath.config],
+                type="Directory",
+            ),
+        )
+        statefulset.spec.template.spec.volumes.append(volume)
+
+        # Add volumeMount
+        for statefulset_container in statefulset.spec.template.spec.containers:
+            if statefulset_container.name != self.container.name:
+                continue
+
+            logger.debug(
+                f"adding volumeMount {hostpath.config} to {self.container.name} container"
+            )
+            statefulset_container.volumeMounts.append(
+                VolumeMount(mountPath=hostpath.mount_path, name=hostpath.config)
+            )
+
+    def _delete_hostpath_from_statefulset(self, hostpath: HostPath, statefulset: StatefulSet):
+        hostpath_unmounted = False
+        for volume in statefulset.spec.template.spec.volumes:
+
+            if hostpath.config != volume.name:
+                continue
+
+            # Remove volumeMount
+            for statefulset_container in statefulset.spec.template.spec.containers:
+                if statefulset_container.name != self.container.name:
+                    continue
+                for volume_mount in statefulset_container.volumeMounts:
+                    if volume_mount.name != hostpath.config:
+                        continue
+
+                    logger.debug(
+                        f"removing volumeMount {hostpath.config} from {self.container.name} container"
+                    )
+                    statefulset_container.volumeMounts.remove(volume_mount)
+
+            # Remove volume
+            logger.debug(
+                f"removing volume {hostpath.config} from {self.charm.app.name} statefulset"
+            )
+            statefulset.spec.template.spec.volumes.remove(volume)
+
+            hostpath_unmounted = True
+        return hostpath_unmounted
+
+    def _get_vscode_command(
+        self,
+        pod_ip: str,
+        user: str = "root",
+        workspace_path: str = "/debug.code-workspace",
+    ) -> str:
+        return f"code --remote ssh-remote+{user}@{pod_ip} {workspace_path}"
+
+    def _restart(self):
+        self.container.exec(["kill", "-HUP", "1"])
diff --git a/installers/charm/osm-ro/lib/charms/osm_ro/v0/ro.py b/installers/charm/osm-ro/lib/charms/osm_ro/v0/ro.py
new file mode 100644
index 0000000..79bee5e
--- /dev/null
+++ b/installers/charm/osm-ro/lib/charms/osm_ro/v0/ro.py
@@ -0,0 +1,178 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+#
+# Learn more at: https://juju.is/docs/sdk
+
+"""Ro library.
+
+This [library](https://juju.is/docs/sdk/libraries) implements both sides of the
+`ro` [interface](https://juju.is/docs/sdk/relations).
+
+The *provider* side of this interface is implemented by the
+[osm-ro Charmed Operator](https://charmhub.io/osm-ro).
+
+Any Charmed Operator that *requires* RO for providing its
+service should implement the *requirer* side of this interface.
+
+In a nutshell using this library to implement a Charmed Operator *requiring*
+RO would look like
+
+```
+$ charmcraft fetch-lib charms.osm_ro.v0.ro
+```
+
+`metadata.yaml`:
+
+```
+requires:
+  ro:
+    interface: ro
+    limit: 1
+```
+
+`src/charm.py`:
+
+```
+from charms.osm_ro.v0.ro import RoRequires
+from ops.charm import CharmBase
+
+
+class MyCharm(CharmBase):
+
+    def __init__(self, *args):
+        super().__init__(*args)
+        self.ro = RoRequires(self)
+        self.framework.observe(
+            self.on["ro"].relation_changed,
+            self._on_ro_relation_changed,
+        )
+        self.framework.observe(
+            self.on["ro"].relation_broken,
+            self._on_ro_relation_broken,
+        )
+        self.framework.observe(
+            self.on["ro"].relation_broken,
+            self._on_ro_broken,
+        )
+
+    def _on_ro_relation_broken(self, event):
+        # Get RO host and port
+        host: str = self.ro.host
+        port: int = self.ro.port
+        # host => "osm-ro"
+        # port => 9999
+
+    def _on_ro_broken(self, event):
+        # Stop service
+        # ...
+        self.unit.status = BlockedStatus("need ro relation")
+```
+
+You can file bugs
+[here](https://osm.etsi.org/bugzilla/enter_bug.cgi), selecting the `devops` module!
+"""
+from typing import Optional
+
+from ops.charm import CharmBase, CharmEvents
+from ops.framework import EventBase, EventSource, Object
+from ops.model import Relation
+
+
+# The unique Charmhub library identifier, never change it
+LIBID = "a34c3331a43f4f6db2b1499ff4d1390d"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 1
+
+RO_HOST_APP_KEY = "host"
+RO_PORT_APP_KEY = "port"
+
+
+class RoRequires(Object):  # pragma: no cover
+    """Requires-side of the Ro relation."""
+
+    def __init__(self, charm: CharmBase, endpoint_name: str = "ro") -> None:
+        super().__init__(charm, endpoint_name)
+        self.charm = charm
+        self._endpoint_name = endpoint_name
+
+    @property
+    def host(self) -> str:
+        """Get ro hostname."""
+        relation: Relation = self.model.get_relation(self._endpoint_name)
+        return (
+            relation.data[relation.app].get(RO_HOST_APP_KEY)
+            if relation and relation.app
+            else None
+        )
+
+    @property
+    def port(self) -> int:
+        """Get ro port number."""
+        relation: Relation = self.model.get_relation(self._endpoint_name)
+        return (
+            int(relation.data[relation.app].get(RO_PORT_APP_KEY))
+            if relation and relation.app
+            else None
+        )
+
+
+class RoProvides(Object):
+    """Provides-side of the Ro relation."""
+
+    def __init__(self, charm: CharmBase, endpoint_name: str = "ro") -> None:
+        super().__init__(charm, endpoint_name)
+        self._endpoint_name = endpoint_name
+
+    def set_host_info(self, host: str, port: int, relation: Optional[Relation] = None) -> None:
+        """Set Ro host and port.
+
+        This function writes in the application data of the relation, therefore,
+        only the unit leader can call it.
+
+        Args:
+            host (str): Ro hostname or IP address.
+            port (int): Ro port.
+            relation (Optional[Relation]): Relation to update.
+                                           If not specified, all relations will be updated.
+
+        Raises:
+            Exception: if a non-leader unit calls this function.
+        """
+        if not self.model.unit.is_leader():
+            raise Exception("only the leader set host information.")
+
+        if relation:
+            self._update_relation_data(host, port, relation)
+            return
+
+        for relation in self.model.relations[self._endpoint_name]:
+            self._update_relation_data(host, port, relation)
+
+    def _update_relation_data(self, host: str, port: int, relation: Relation) -> None:
+        """Update data in relation if needed."""
+        relation.data[self.model.app][RO_HOST_APP_KEY] = host
+        relation.data[self.model.app][RO_PORT_APP_KEY] = str(port)
diff --git a/installers/charm/osm-ro/metadata.yaml b/installers/charm/osm-ro/metadata.yaml
new file mode 100644
index 0000000..a94036a
--- /dev/null
+++ b/installers/charm/osm-ro/metadata.yaml
@@ -0,0 +1,66 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+#
+# This file populates the Overview on Charmhub.
+# See https://juju.is/docs/some-url-to-be-determined/ for a checklist and guidance.
+
+name: osm-ro
+
+# The following metadata are human-readable and will be published prominently on Charmhub.
+
+display-name: OSM RO
+
+summary: OSM Resource Orchestrator (RO)
+
+description: |
+  A Kubernetes operator that deploys the Resource Orchestrator of OSM.
+
+  Resource orchestrator module's main responsibility is managing the
+  VIM and SDN operations by taking orders through the LCM and Kafka
+  message queue.
+
+  This charm doesn't make sense on its own.
+  See more:
+    - https://charmhub.io/osm
+
+containers:
+  ro:
+    resource: ro-image
+
+# This file populates the Resources tab on Charmhub.
+
+resources:
+  ro-image:
+    type: oci-image
+    description: OCI image for ro
+    upstream-source: opensourcemano/ro
+
+requires:
+  kafka:
+    interface: kafka
+    limit: 1
+  mongodb:
+    interface: mongodb_client
+    limit: 1
+
+provides:
+  ro:
+    interface: ro
diff --git a/installers/charm/osm-ro/pyproject.toml b/installers/charm/osm-ro/pyproject.toml
new file mode 100644
index 0000000..16cf0f4
--- /dev/null
+++ b/installers/charm/osm-ro/pyproject.toml
@@ -0,0 +1,52 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+
+# Testing tools configuration
+[tool.coverage.run]
+branch = true
+
+[tool.coverage.report]
+show_missing = true
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+log_cli_level = "INFO"
+
+# Formatting tools configuration
+[tool.black]
+line-length = 99
+target-version = ["py38"]
+
+[tool.isort]
+profile = "black"
+
+# Linting tools configuration
+[tool.flake8]
+max-line-length = 99
+max-doc-length = 99
+max-complexity = 10
+exclude = [".git", "__pycache__", ".tox", "build", "dist", "*.egg_info", "venv"]
+select = ["E", "W", "F", "C", "N", "R", "D", "H"]
+# Ignore W503, E501 because using black creates errors with this
+# Ignore D107 Missing docstring in __init__
+ignore = ["W503", "E501", "D107"]
+# D100, D101, D102, D103: Ignore missing docstrings in tests
+per-file-ignores = ["tests/*:D100,D101,D102,D103,D104"]
+docstring-convention = "google"
diff --git a/installers/charm/osm-ro/requirements.txt b/installers/charm/osm-ro/requirements.txt
new file mode 100644
index 0000000..398d4ad
--- /dev/null
+++ b/installers/charm/osm-ro/requirements.txt
@@ -0,0 +1,23 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+ops < 2.2
+lightkube
+lightkube-models
+# git+https://github.com/charmed-osm/config-validator/
diff --git a/installers/charm/osm-ro/src/charm.py b/installers/charm/osm-ro/src/charm.py
new file mode 100755
index 0000000..89da4f1
--- /dev/null
+++ b/installers/charm/osm-ro/src/charm.py
@@ -0,0 +1,338 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+#
+# Learn more at: https://juju.is/docs/sdk
+
+"""OSM RO charm.
+
+See more: https://charmhub.io/osm
+"""
+
+import base64
+import logging
+from typing import Any, Dict
+
+from charms.data_platform_libs.v0.data_interfaces import DatabaseRequires
+from charms.kafka_k8s.v0.kafka import KafkaEvents, KafkaRequires
+from charms.observability_libs.v1.kubernetes_service_patch import KubernetesServicePatch
+from charms.osm_libs.v0.utils import (
+    CharmError,
+    DebugMode,
+    HostPath,
+    check_container_ready,
+    check_service_active,
+)
+from charms.osm_ro.v0.ro import RoProvides
+from lightkube.models.core_v1 import ServicePort
+from ops.charm import ActionEvent, CharmBase, RelationJoinedEvent
+from ops.framework import StoredState
+from ops.main import main
+from ops.model import ActiveStatus, Container
+
+ro_host_paths = {
+    "NG-RO": "/usr/lib/python3/dist-packages/osm_ng_ro",
+    "RO-plugin": "/usr/lib/python3/dist-packages/osm_ro_plugin",
+    "RO-SDN-arista_cloudvision": "/usr/lib/python3/dist-packages/osm_rosdn_arista_cloudvision",
+    "RO-SDN-dpb": "/usr/lib/python3/dist-packages/osm_rosdn_dpb",
+    "RO-SDN-dynpac": "/usr/lib/python3/dist-packages/osm_rosdn_dynpac",
+    "RO-SDN-floodlight_openflow": "/usr/lib/python3/dist-packages/osm_rosdn_floodlightof",
+    "RO-SDN-ietfl2vpn": "/usr/lib/python3/dist-packages/osm_rosdn_ietfl2vpn",
+    "RO-SDN-juniper_contrail": "/usr/lib/python3/dist-packages/osm_rosdn_juniper_contrail",
+    "RO-SDN-odl_openflow": "/usr/lib/python3/dist-packages/osm_rosdn_odlof",
+    "RO-SDN-onos_openflow": "/usr/lib/python3/dist-packages/osm_rosdn_onosof",
+    "RO-SDN-onos_vpls": "/usr/lib/python3/dist-packages/osm_rosdn_onos_vpls",
+    "RO-VIM-aws": "/usr/lib/python3/dist-packages/osm_rovim_aws",
+    "RO-VIM-azure": "/usr/lib/python3/dist-packages/osm_rovim_azure",
+    "RO-VIM-gcp": "/usr/lib/python3/dist-packages/osm_rovim_gcp",
+    "RO-VIM-openstack": "/usr/lib/python3/dist-packages/osm_rovim_openstack",
+    "RO-VIM-openvim": "/usr/lib/python3/dist-packages/osm_rovim_openvim",
+    "RO-VIM-vmware": "/usr/lib/python3/dist-packages/osm_rovim_vmware",
+}
+HOSTPATHS = [
+    HostPath(
+        config="ro-hostpath",
+        container_path="/usr/lib/python3/dist-packages/",
+        submodules=ro_host_paths,
+    ),
+    HostPath(
+        config="common-hostpath",
+        container_path="/usr/lib/python3/dist-packages/osm_common",
+    ),
+]
+SERVICE_PORT = 9090
+USER = GROUP = "appuser"
+
+logger = logging.getLogger(__name__)
+
+
+def decode(content: str):
+    """Base64 decoding of a string."""
+    return base64.b64decode(content.encode("utf-8")).decode("utf-8")
+
+
+class OsmRoCharm(CharmBase):
+    """OSM RO Kubernetes sidecar charm."""
+
+    on = KafkaEvents()
+    service_name = "ro"
+    _stored = StoredState()
+
+    def __init__(self, *args):
+        super().__init__(*args)
+        self._stored.set_default(certificates=set())
+        self.kafka = KafkaRequires(self)
+        self.mongodb_client = DatabaseRequires(self, "mongodb", database_name="osm")
+        self._observe_charm_events()
+        self._patch_k8s_service()
+        self.ro = RoProvides(self)
+        self.container: Container = self.unit.get_container("ro")
+        self.debug_mode = DebugMode(self, self._stored, self.container, HOSTPATHS)
+
+    # ---------------------------------------------------------------------------
+    #   Handlers for Charm Events
+    # ---------------------------------------------------------------------------
+
+    def _on_config_changed(self, _) -> None:
+        """Handler for the config-changed event."""
+        try:
+            self._validate_config()
+            self._check_relations()
+            # Check if the container is ready.
+            # Eventually it will become ready after the first pebble-ready event.
+            check_container_ready(self.container)
+
+            self._configure_certificates()
+            if not self.debug_mode.started:
+                self._configure_service()
+            self._update_ro_relation()
+
+            # Update charm status
+            self._on_update_status()
+        except CharmError as e:
+            logger.debug(e.message)
+            self.unit.status = e.status
+
+    def _on_update_status(self, _=None) -> None:
+        """Handler for the update-status event."""
+        try:
+            self._validate_config()
+            self._check_relations()
+            check_container_ready(self.container)
+            if self.debug_mode.started:
+                return
+            check_service_active(self.container, self.service_name)
+            self.unit.status = ActiveStatus()
+        except CharmError as e:
+            logger.debug(e.message)
+            self.unit.status = e.status
+
+    def _on_required_relation_broken(self, _) -> None:
+        """Handler for the kafka-broken event."""
+        try:
+            check_container_ready(self.container)
+            check_service_active(self.container, "ro")
+            self.container.stop("ro")
+        except CharmError:
+            pass
+
+        self._on_update_status()
+
+    def _update_ro_relation(self, event: RelationJoinedEvent = None) -> None:
+        """Handler for the ro-relation-joined event."""
+        try:
+            if self.unit.is_leader():
+                check_container_ready(self.container)
+                check_service_active(self.container, "ro")
+                self.ro.set_host_info(
+                    self.app.name, SERVICE_PORT, event.relation if event else None
+                )
+        except CharmError as e:
+            self.unit.status = e.status
+
+    def _on_get_debug_mode_information_action(self, event: ActionEvent) -> None:
+        """Handler for the get-debug-mode-information action event."""
+        if not self.debug_mode.started:
+            event.fail(
+                f"debug-mode has not started. Hint: juju config {self.app.name} debug-mode=true"
+            )
+            return
+
+        debug_info = {"command": self.debug_mode.command, "password": self.debug_mode.password}
+        event.set_results(debug_info)
+
+    # ---------------------------------------------------------------------------
+    #   Validation and configuration and more
+    # ---------------------------------------------------------------------------
+
+    def _patch_k8s_service(self) -> None:
+        port = ServicePort(SERVICE_PORT, name=f"{self.app.name}")
+        self.service_patcher = KubernetesServicePatch(self, [port])
+
+    def _observe_charm_events(self) -> None:
+        event_handler_mapping = {
+            # Core lifecycle events
+            self.on.ro_pebble_ready: self._on_config_changed,
+            self.on.config_changed: self._on_config_changed,
+            self.on.update_status: self._on_update_status,
+            # Relation events
+            self.on.kafka_available: self._on_config_changed,
+            self.on["kafka"].relation_broken: self._on_required_relation_broken,
+            self.mongodb_client.on.database_created: self._on_config_changed,
+            self.on["mongodb"].relation_broken: self._on_required_relation_broken,
+            self.on.ro_relation_joined: self._update_ro_relation,
+            # Action events
+            self.on.get_debug_mode_information_action: self._on_get_debug_mode_information_action,
+        }
+
+        for event, handler in event_handler_mapping.items():
+            self.framework.observe(event, handler)
+
+    def _is_database_available(self) -> bool:
+        try:
+            return self.mongodb_client.is_resource_created()
+        except KeyError:
+            return False
+
+    def _validate_config(self) -> None:
+        """Validate charm configuration.
+
+        Raises:
+            CharmError: if charm configuration is invalid.
+        """
+        logger.debug("validating charm config")
+        if self.config["log-level"].upper() not in [
+            "TRACE",
+            "DEBUG",
+            "INFO",
+            "WARN",
+            "ERROR",
+            "FATAL",
+        ]:
+            raise CharmError("invalid value for log-level option")
+
+        refresh_period = self.config.get("period_refresh_active")
+        if refresh_period and refresh_period < 60 and refresh_period != -1:
+            raise ValueError(
+                "Refresh Period is too tight, insert >= 60 seconds or disable using -1"
+            )
+
+    def _check_relations(self) -> None:
+        """Validate charm relations.
+
+        Raises:
+            CharmError: if charm configuration is invalid.
+        """
+        logger.debug("check for missing relations")
+        missing_relations = []
+
+        if not self.kafka.host or not self.kafka.port:
+            missing_relations.append("kafka")
+        if not self._is_database_available():
+            missing_relations.append("mongodb")
+
+        if missing_relations:
+            relations_str = ", ".join(missing_relations)
+            one_relation_missing = len(missing_relations) == 1
+            error_msg = f'need {relations_str} relation{"" if one_relation_missing else "s"}'
+            logger.warning(error_msg)
+            raise CharmError(error_msg)
+
+    def _configure_certificates(self) -> None:
+        """Push certificates to the RO container."""
+        if not (certificate_config := self.config.get("certificates")):
+            return
+
+        certificates_list = certificate_config.split(",")
+        updated_certificates = set()
+
+        for certificate in certificates_list:
+            if ":" not in certificate:
+                continue
+            name, content = certificate.split(":")
+            content = decode(content)
+            self.container.push(
+                f"/certs/{name}",
+                content,
+                permissions=0o400,
+                make_dirs=True,
+                user=USER,
+                group=GROUP,
+            )
+            updated_certificates.add(name)
+            self._stored.certificates.add(name)
+            logger.info(f"certificate {name} pushed successfully")
+
+        stored_certificates = {c for c in self._stored.certificates}
+        for certificate_to_remove in stored_certificates.difference(updated_certificates):
+            self.container.remove_path(f"/certs/{certificate_to_remove}")
+            self._stored.certificates.remove(certificate_to_remove)
+            logger.info(f"certificate {certificate_to_remove} removed successfully")
+
+    def _configure_service(self) -> None:
+        """Add Pebble layer with the ro service."""
+        logger.debug(f"configuring {self.app.name} service")
+        self.container.add_layer("ro", self._get_layer(), combine=True)
+        self.container.replan()
+
+    def _get_layer(self) -> Dict[str, Any]:
+        """Get layer for Pebble."""
+        return {
+            "summary": "ro layer",
+            "description": "pebble config layer for ro",
+            "services": {
+                "ro": {
+                    "override": "replace",
+                    "summary": "ro service",
+                    "command": "/bin/sh -c 'cd /app/osm_ro && python3 -u -m osm_ng_ro.ro_main'",  # cd /app/osm_nbi is needed until we upgrade Juju to 3.x.
+                    "startup": "enabled",
+                    "user": USER,
+                    "group": GROUP,
+                    "working-dir": "/app/osm_ro",  # This parameter has no effect in Juju 2.9.x.
+                    "environment": {
+                        # General configuration
+                        "OSMRO_LOG_LEVEL": self.config["log-level"].upper(),
+                        # Kafka configuration
+                        "OSMRO_MESSAGE_HOST": self.kafka.host,
+                        "OSMRO_MESSAGE_PORT": self.kafka.port,
+                        "OSMRO_MESSAGE_DRIVER": "kafka",
+                        # Database configuration
+                        "OSMRO_DATABASE_DRIVER": "mongo",
+                        "OSMRO_DATABASE_URI": self._get_mongodb_uri(),
+                        "OSMRO_DATABASE_COMMONKEY": self.config["database-commonkey"],
+                        # Storage configuration
+                        "OSMRO_STORAGE_DRIVER": "mongo",
+                        "OSMRO_STORAGE_PATH": "/app/storage",
+                        "OSMRO_STORAGE_COLLECTION": "files",
+                        "OSMRO_STORAGE_URI": self._get_mongodb_uri(),
+                        "OSMRO_PERIOD_REFRESH_ACTIVE": self.config.get("period_refresh_active")
+                        or 60,
+                    },
+                }
+            },
+        }
+
+    def _get_mongodb_uri(self):
+        return list(self.mongodb_client.fetch_relation_data().values())[0]["uris"]
+
+
+if __name__ == "__main__":  # pragma: no cover
+    main(OsmRoCharm)
diff --git a/installers/charm/osm-ro/src/legacy_interfaces.py b/installers/charm/osm-ro/src/legacy_interfaces.py
new file mode 100644
index 0000000..da9483e
--- /dev/null
+++ b/installers/charm/osm-ro/src/legacy_interfaces.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+# flake8: noqa
+
+import ops
+
+
+class BaseRelationClient(ops.framework.Object):
+    """Requires side of a Kafka Endpoint"""
+
+    def __init__(
+        self,
+        charm: ops.charm.CharmBase,
+        relation_name: str,
+        mandatory_fields: list = [],
+    ):
+        super().__init__(charm, relation_name)
+        self.relation_name = relation_name
+        self.mandatory_fields = mandatory_fields
+        self._update_relation()
+
+    def get_data_from_unit(self, key: str):
+        if not self.relation:
+            # This update relation doesn't seem to be needed, but I added it because apparently
+            # the data is empty in the unit tests.
+            # In reality, the constructor is called in every hook.
+            # In the unit tests when doing an update_relation_data, apparently it is not called.
+            self._update_relation()
+        if self.relation:
+            for unit in self.relation.units:
+                data = self.relation.data[unit].get(key)
+                if data:
+                    return data
+
+    def get_data_from_app(self, key: str):
+        if not self.relation or self.relation.app not in self.relation.data:
+            # This update relation doesn't seem to be needed, but I added it because apparently
+            # the data is empty in the unit tests.
+            # In reality, the constructor is called in every hook.
+            # In the unit tests when doing an update_relation_data, apparently it is not called.
+            self._update_relation()
+        if self.relation and self.relation.app in self.relation.data:
+            data = self.relation.data[self.relation.app].get(key)
+            if data:
+                return data
+
+    def is_missing_data_in_unit(self):
+        return not all([self.get_data_from_unit(field) for field in self.mandatory_fields])
+
+    def is_missing_data_in_app(self):
+        return not all([self.get_data_from_app(field) for field in self.mandatory_fields])
+
+    def _update_relation(self):
+        self.relation = self.framework.model.get_relation(self.relation_name)
+
+
+class MongoClient(BaseRelationClient):
+    """Requires side of a Mongo Endpoint"""
+
+    mandatory_fields_mapping = {
+        "reactive": ["connection_string"],
+        "ops": ["replica_set_uri", "replica_set_name"],
+    }
+
+    def __init__(self, charm: ops.charm.CharmBase, relation_name: str):
+        super().__init__(charm, relation_name, mandatory_fields=[])
+
+    @property
+    def connection_string(self):
+        if self.is_opts():
+            replica_set_uri = self.get_data_from_unit("replica_set_uri")
+            replica_set_name = self.get_data_from_unit("replica_set_name")
+            return f"{replica_set_uri}?replicaSet={replica_set_name}"
+        else:
+            return self.get_data_from_unit("connection_string")
+
+    def is_opts(self):
+        return not self.is_missing_data_in_unit_ops()
+
+    def is_missing_data_in_unit(self):
+        return self.is_missing_data_in_unit_ops() and self.is_missing_data_in_unit_reactive()
+
+    def is_missing_data_in_unit_ops(self):
+        return not all(
+            [self.get_data_from_unit(field) for field in self.mandatory_fields_mapping["ops"]]
+        )
+
+    def is_missing_data_in_unit_reactive(self):
+        return not all(
+            [self.get_data_from_unit(field) for field in self.mandatory_fields_mapping["reactive"]]
+        )
diff --git a/installers/charm/osm-ro/tests/integration/test_charm.py b/installers/charm/osm-ro/tests/integration/test_charm.py
new file mode 100644
index 0000000..38e9ad9
--- /dev/null
+++ b/installers/charm/osm-ro/tests/integration/test_charm.py
@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+# Learn more about testing at: https://juju.is/docs/sdk/testing
+
+import asyncio
+import logging
+from pathlib import Path
+
+import pytest
+import yaml
+from pytest_operator.plugin import OpsTest
+
+logger = logging.getLogger(__name__)
+
+METADATA = yaml.safe_load(Path("./metadata.yaml").read_text())
+RO_APP = METADATA["name"]
+KAFKA_CHARM = "kafka-k8s"
+KAFKA_APP = "kafka"
+MONGO_DB_CHARM = "mongodb-k8s"
+MONGO_DB_APP = "mongodb"
+ZOOKEEPER_CHARM = "zookeeper-k8s"
+ZOOKEEPER_APP = "zookeeper"
+APPS = [KAFKA_APP, MONGO_DB_APP, ZOOKEEPER_APP, RO_APP]
+
+
+@pytest.mark.abort_on_fail
+async def test_ro_is_deployed(ops_test: OpsTest):
+    charm = await ops_test.build_charm(".")
+    resources = {"ro-image": METADATA["resources"]["ro-image"]["upstream-source"]}
+
+    await asyncio.gather(
+        ops_test.model.deploy(charm, resources=resources, application_name=RO_APP, series="jammy"),
+        ops_test.model.deploy(ZOOKEEPER_CHARM, application_name=ZOOKEEPER_APP, channel="stable"),
+        ops_test.model.deploy(KAFKA_CHARM, application_name=KAFKA_APP, channel="stable"),
+        ops_test.model.deploy(MONGO_DB_CHARM, application_name=MONGO_DB_APP, channel="5/edge"),
+    )
+
+    async with ops_test.fast_forward():
+        await ops_test.model.wait_for_idle(
+            apps=APPS,
+            timeout=300,
+        )
+    assert ops_test.model.applications[RO_APP].status == "blocked"
+    unit = ops_test.model.applications[RO_APP].units[0]
+    assert unit.workload_status_message == "need kafka, mongodb relations"
+
+    logger.info("Adding relations")
+    await ops_test.model.add_relation(KAFKA_APP, ZOOKEEPER_APP)
+    await ops_test.model.add_relation(
+        "{}:mongodb".format(RO_APP), "{}:database".format(MONGO_DB_APP)
+    )
+    await ops_test.model.add_relation(RO_APP, KAFKA_APP)
+
+    async with ops_test.fast_forward():
+        await ops_test.model.wait_for_idle(
+            apps=APPS,
+            status="active",
+            timeout=300,
+        )
+
+
+@pytest.mark.abort_on_fail
+async def test_ro_scales(ops_test: OpsTest):
+    logger.info("Scaling osm-ro")
+    expected_units = 3
+    assert len(ops_test.model.applications[RO_APP].units) == 1
+    await ops_test.model.applications[RO_APP].scale(expected_units)
+    async with ops_test.fast_forward():
+        await ops_test.model.wait_for_idle(
+            apps=[RO_APP], status="active", timeout=1000, wait_for_exact_units=expected_units
+        )
+
+
+@pytest.mark.abort_on_fail
+async def test_ro_blocks_without_kafka(ops_test: OpsTest):
+    await asyncio.gather(ops_test.model.applications[KAFKA_APP].remove())
+    async with ops_test.fast_forward():
+        await ops_test.model.wait_for_idle(apps=[RO_APP])
+    assert ops_test.model.applications[RO_APP].status == "blocked"
+    for unit in ops_test.model.applications[RO_APP].units:
+        assert unit.workload_status_message == "need kafka relation"
diff --git a/installers/charm/osm-ro/tests/unit/test_charm.py b/installers/charm/osm-ro/tests/unit/test_charm.py
new file mode 100644
index 0000000..d0353ab
--- /dev/null
+++ b/installers/charm/osm-ro/tests/unit/test_charm.py
@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+# Learn more about testing at: https://juju.is/docs/sdk/testing
+
+import pytest
+from ops.model import ActiveStatus, BlockedStatus
+from ops.testing import Harness
+from pytest_mock import MockerFixture
+
+from charm import CharmError, OsmRoCharm, check_service_active
+
+container_name = "ro"
+service_name = "ro"
+
+
+@pytest.fixture
+def harness(mocker: MockerFixture):
+    mocker.patch("charm.KubernetesServicePatch", lambda x, y: None)
+    harness = Harness(OsmRoCharm)
+    harness.begin()
+    harness.container_pebble_ready(container_name)
+    yield harness
+    harness.cleanup()
+
+
+def test_missing_relations(harness: Harness):
+    harness.charm.on.config_changed.emit()
+    assert type(harness.charm.unit.status) == BlockedStatus
+    assert all(relation in harness.charm.unit.status.message for relation in ["mongodb", "kafka"])
+
+
+def test_ready(harness: Harness):
+    _add_relations(harness)
+    assert harness.charm.unit.status == ActiveStatus()
+
+
+def test_container_stops_after_relation_broken(harness: Harness):
+    harness.charm.on[container_name].pebble_ready.emit(container_name)
+    container = harness.charm.unit.get_container(container_name)
+    relation_ids = _add_relations(harness)
+    check_service_active(container, service_name)
+    harness.remove_relation(relation_ids[0])
+    with pytest.raises(CharmError):
+        check_service_active(container, service_name)
+
+
+def test_ro_relation_joined(harness: Harness):
+    harness.set_leader(True)
+    _add_relations(harness)
+    relation_id = harness.add_relation("ro", "lcm")
+    harness.add_relation_unit(relation_id, "lcm/0")
+    relation_data = harness.get_relation_data(relation_id, harness.charm.app.name)
+    assert harness.charm.unit.status == ActiveStatus()
+    assert relation_data == {"host": harness.charm.app.name, "port": "9090"}
+
+
+def test_certificates(harness: Harness):
+    # aGVsbG8K: "hello\n"
+    # aGVsbG8gYWdhaW4K: "hello again\n"
+    _add_relations(harness)
+    harness.update_config({"certificates": "cert1:aGVsbG8K,cert2:aGVsbG8gYWdhaW4K"})
+    for cert_name, content in {"cert1": "hello\n", "cert2": "hello again\n"}.items():
+        assert harness.charm.container.exists(f"/certs/{cert_name}")
+        assert harness.charm.container.pull(f"/certs/{cert_name}").read() == content
+
+
+def _add_relations(harness: Harness):
+    relation_ids = []
+    # Add mongo relation
+    relation_id = harness.add_relation("mongodb", "mongodb")
+    harness.add_relation_unit(relation_id, "mongodb/0")
+    harness.update_relation_data(
+        relation_id,
+        "mongodb",
+        {"uris": "mongodb://:1234", "username": "user", "password": "password"},
+    )
+    relation_ids.append(relation_id)
+    # Add kafka relation
+    relation_id = harness.add_relation("kafka", "kafka")
+    harness.add_relation_unit(relation_id, "kafka/0")
+    harness.update_relation_data(relation_id, "kafka", {"host": "kafka", "port": "9092"})
+    relation_ids.append(relation_id)
+    return relation_ids
diff --git a/installers/charm/osm-ro/tox.ini b/installers/charm/osm-ro/tox.ini
new file mode 100644
index 0000000..c6cc629
--- /dev/null
+++ b/installers/charm/osm-ro/tox.ini
@@ -0,0 +1,95 @@
+# Copyright 2022 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+
+[tox]
+skipsdist=True
+skip_missing_interpreters = True
+envlist = lint, unit, integration
+
+[vars]
+src_path = {toxinidir}/src/
+tst_path = {toxinidir}/tests/
+lib_path = {toxinidir}/lib/charms/osm_ro
+all_path = {[vars]src_path} {[vars]tst_path}
+
+[testenv]
+basepython = python3.8
+setenv =
+  PYTHONPATH = {toxinidir}:{toxinidir}/lib:{[vars]src_path}
+  PYTHONBREAKPOINT=ipdb.set_trace
+  PY_COLORS=1
+passenv =
+  PYTHONPATH
+  CHARM_BUILD_DIR
+  MODEL_SETTINGS
+
+[testenv:fmt]
+description = Apply coding style standards to code
+deps =
+    black
+    isort
+commands =
+    isort {[vars]all_path}
+    black {[vars]all_path}
+
+[testenv:lint]
+description = Check code against coding style standards
+deps =
+    black
+    flake8==4.0.1
+    flake8-docstrings
+    flake8-builtins
+    pyproject-flake8
+    pep8-naming
+    isort
+    codespell
+commands =
+    # uncomment the following line if this charm owns a lib
+    codespell {[vars]lib_path} --ignore-words-list=Ro,RO,ro
+    codespell {toxinidir} --skip {toxinidir}/.git --skip {toxinidir}/.tox \
+      --skip {toxinidir}/build --skip {toxinidir}/lib --skip {toxinidir}/venv \
+      --skip {toxinidir}/.mypy_cache --skip {toxinidir}/icon.svg --ignore-words-list=Ro,RO,ro
+    # pflake8 wrapper supports config from pyproject.toml
+    pflake8 {[vars]all_path}
+    isort --check-only --diff {[vars]all_path}
+    black --check --diff {[vars]all_path}
+
+[testenv:unit]
+description = Run unit tests
+deps =
+    pytest
+    pytest-mock
+    coverage[toml]
+    -r{toxinidir}/requirements.txt
+commands =
+    coverage run --source={[vars]src_path},{[vars]lib_path} \
+        -m pytest --ignore={[vars]tst_path}integration -v --tb native -s {posargs}
+    coverage report
+    coverage xml
+
+[testenv:integration]
+description = Run integration tests
+deps =
+    pytest
+    juju<3
+    pytest-operator
+    -r{toxinidir}/requirements.txt
+commands =
+    pytest -v --tb native --ignore={[vars]tst_path}unit --log-cli-level=INFO -s {posargs} --cloud microk8s
\ No newline at end of file