diff --git a/installers/charm/mon/.gitignore b/installers/charm/mon/.gitignore
new file mode 100644
index 0000000..0be86d6
--- /dev/null
+++ b/installers/charm/mon/.gitignore
@@ -0,0 +1,28 @@
+# Copyright 2020 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
+.vscode
+build
+mon.charm
+.coverage
+.stestr
+cover
diff --git a/installers/charm/mon/.yamllint.yaml b/installers/charm/mon/.yamllint.yaml
new file mode 100644
index 0000000..c20ac8d
--- /dev/null
+++ b/installers/charm/mon/.yamllint.yaml
@@ -0,0 +1,33 @@
+# Copyright 2020 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
+##
+
+---
+extends: default
+
+yaml-files:
+  - "*.yaml"
+  - "*.yml"
+  - ".yamllint"
+ignore: |
+  .tox
+  build/
+  mod/
+  lib/
diff --git a/installers/charm/mon/README.md b/installers/charm/mon/README.md
new file mode 100644
index 0000000..216a784
--- /dev/null
+++ b/installers/charm/mon/README.md
@@ -0,0 +1,23 @@
+<!-- Copyright 2020 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 -->
+
+# MON operator Charm for Kubernetes
+
+## Requirements
diff --git a/installers/charm/mon/config.yaml b/installers/charm/mon/config.yaml
new file mode 100644
index 0000000..9480ea7
--- /dev/null
+++ b/installers/charm/mon/config.yaml
@@ -0,0 +1,62 @@
+# Copyright 2020 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
+##
+
+options:
+  openstack_default_granularity:
+    description: Openstack default granularity
+    type: int
+    default: 300
+  global_request_timeout:
+    description: Global request timeout
+    type: int
+    default: 10
+  log_level:
+    description: Log level
+    type: string
+    default: INFO
+  database_commonkey:
+    description: Database common key
+    type: string
+    default: osm
+  collector_interval:
+    description: Collector interval
+    type: int
+    default: 30
+  evaluator_interval:
+    description: Evaluator interval
+    type: int
+    default: 30
+  vca_host:
+    type: string
+    description: "The VCA host."
+    default: "admin"
+  vca_user:
+    type: string
+    description: "The VCA user name."
+    default: "admin"
+  vca_password:
+    type: string
+    description: "The VCA user password."
+    default: "secret"
+  vca_cacert:
+    type: string
+    description: "The VCA cacert."
+    default: ""
diff --git a/installers/charm/mon/metadata.yaml b/installers/charm/mon/metadata.yaml
new file mode 100644
index 0000000..2578b1e
--- /dev/null
+++ b/installers/charm/mon/metadata.yaml
@@ -0,0 +1,47 @@
+# Copyright 2020 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
+##
+
+name: mon
+summary: OSM Monitoring (MON)
+description: |
+  A CAAS charm to deploy OSM's Monitoring (MON).
+series:
+  - kubernetes
+tags:
+  - kubernetes
+  - osm
+  - mon
+min-juju-version: 2.8.0
+deployment:
+  type: stateless
+  service: cluster
+resources:
+  image:
+    type: oci-image
+    description: OSM docker image for MON
+    upstream-source: "opensourcemano/mon:8"
+requires:
+  kafka:
+    interface: kafka
+  mongodb:
+    interface: mongodb
+  prometheus:
+    interface: prometheus
diff --git a/installers/charm/mon/requirements.txt b/installers/charm/mon/requirements.txt
new file mode 100644
index 0000000..24f1672
--- /dev/null
+++ b/installers/charm/mon/requirements.txt
@@ -0,0 +1,24 @@
+# Copyright 2020 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
+pydantic
+git+https://github.com/juju-solutions/resource-oci-image/@c5778285d332edf3d9a538f9d0c06154b7ec1b0b#egg=oci-image
diff --git a/installers/charm/mon/src/charm.py b/installers/charm/mon/src/charm.py
new file mode 100755
index 0000000..a6f405f
--- /dev/null
+++ b/installers/charm/mon/src/charm.py
@@ -0,0 +1,281 @@
+#!/usr/bin/env python3
+# Copyright 2020 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
+##
+
+import logging
+from pydantic import ValidationError
+from typing import Any, Dict, NoReturn
+
+from ops.charm import CharmBase, CharmEvents
+from ops.framework import EventBase, EventSource, StoredState
+from ops.main import main
+from ops.model import ActiveStatus, BlockedStatus, MaintenanceStatus
+from oci_image import OCIImageResource, OCIImageResourceError
+
+from pod_spec import make_pod_spec
+
+LOGGER = logging.getLogger(__name__)
+
+MON_PORT = 8000
+
+
+class ConfigurePodEvent(EventBase):
+    """Configure Pod event"""
+
+    pass
+
+
+class MonEvents(CharmEvents):
+    """MON Events"""
+
+    configure_pod = EventSource(ConfigurePodEvent)
+
+
+class MonCharm(CharmBase):
+    """MON Charm."""
+
+    state = StoredState()
+    on = MonEvents()
+
+    def __init__(self, *args) -> NoReturn:
+        """MON Charm constructor."""
+        super().__init__(*args)
+
+        # Internal state initialization
+        self.state.set_default(pod_spec=None)
+
+        # Message bus data initialization
+        self.state.set_default(message_host=None)
+        self.state.set_default(message_port=None)
+
+        # Database data initialization
+        self.state.set_default(database_uri=None)
+
+        # Prometheus data initialization
+        self.state.set_default(prometheus_host=None)
+        self.state.set_default(prometheus_port=None)
+
+        self.port = MON_PORT
+        self.image = OCIImageResource(self, "image")
+
+        # Registering regular events
+        self.framework.observe(self.on.start, self.configure_pod)
+        self.framework.observe(self.on.config_changed, self.configure_pod)
+        self.framework.observe(self.on.upgrade_charm, self.configure_pod)
+
+        # Registering custom internal events
+        self.framework.observe(self.on.configure_pod, self.configure_pod)
+
+        # Registering required relation events
+        self.framework.observe(
+            self.on.kafka_relation_changed, self._on_kafka_relation_changed
+        )
+        self.framework.observe(
+            self.on.mongodb_relation_changed, self._on_mongodb_relation_changed
+        )
+        self.framework.observe(
+            self.on.prometheus_relation_changed, self._on_prometheus_relation_changed
+        )
+
+        # Registering required relation departed events
+        self.framework.observe(
+            self.on.kafka_relation_departed, self._on_kafka_relation_departed
+        )
+        self.framework.observe(
+            self.on.mongodb_relation_departed, self._on_mongodb_relation_departed
+        )
+        self.framework.observe(
+            self.on.prometheus_relation_departed, self._on_prometheus_relation_departed
+        )
+
+    def _on_kafka_relation_changed(self, event: EventBase) -> NoReturn:
+        """Reads information about the kafka relation.
+
+        Args:
+            event (EventBase): Kafka relation event.
+        """
+        data_loc = event.unit if event.unit else event.app
+
+        message_host = event.relation.data[data_loc].get("host")
+        message_port = event.relation.data[data_loc].get("port")
+
+        if (
+            message_host
+            and message_port
+            and (
+                self.state.message_host != message_host
+                or self.state.message_port != message_port
+            )
+        ):
+            self.state.message_host = message_host
+            self.state.message_port = message_port
+            self.on.configure_pod.emit()
+
+    def _on_kafka_relation_departed(self, event: EventBase) -> NoReturn:
+        """Clear kafka relation data.
+
+        Args:
+            event (EventBase): Kafka relation event.
+        """
+        self.state.message_host = None
+        self.state.message_port = None
+        self.on.configure_pod.emit()
+
+    def _on_mongodb_relation_changed(self, event: EventBase) -> NoReturn:
+        """Reads information about the DB relation.
+
+        Args:
+            event (EventBase): DB relation event.
+        """
+        data_loc = event.unit if event.unit else event.app
+
+        database_uri = event.relation.data[data_loc].get("connection_string")
+
+        if database_uri and self.state.database_uri != database_uri:
+            self.state.database_uri = database_uri
+            self.on.configure_pod.emit()
+
+    def _on_mongodb_relation_departed(self, event: EventBase) -> NoReturn:
+        """Clear mongodb relation data.
+
+        Args:
+            event (EventBase): DB relation event.
+        """
+        self.state.database_uri = None
+        self.on.configure_pod.emit()
+
+    def _on_prometheus_relation_changed(self, event: EventBase) -> NoReturn:
+        """Reads information about the prometheus relation.
+
+        Args:
+            event (EventBase): Prometheus relation event.
+        """
+        data_loc = event.unit if event.unit else event.app
+
+        prometheus_host = event.relation.data[data_loc].get("hostname")
+        prometheus_port = event.relation.data[data_loc].get("port")
+
+        if (
+            prometheus_host
+            and prometheus_port
+            and (
+                self.state.prometheus_host != prometheus_host
+                or self.state.prometheus_port != prometheus_port
+            )
+        ):
+            self.state.prometheus_host = prometheus_host
+            self.state.prometheus_port = prometheus_port
+            self.on.configure_pod.emit()
+
+    def _on_prometheus_relation_departed(self, event: EventBase) -> NoReturn:
+        """Clear prometheus relation data.
+
+        Args:
+            event (EventBase): Prometheus relation event.
+        """
+        self.state.prometheus_host = None
+        self.state.prometheus_port = None
+        self.on.configure_pod.emit()
+
+    def _missing_relations(self) -> str:
+        """Checks if there missing relations.
+
+        Returns:
+            str: string with missing relations
+        """
+        data_status = {
+            "kafka": self.state.message_host,
+            "mongodb": self.state.database_uri,
+            "prometheus": self.state.prometheus_host,
+        }
+
+        missing_relations = [k for k, v in data_status.items() if not v]
+
+        return ", ".join(missing_relations)
+
+    @property
+    def relation_state(self) -> Dict[str, Any]:
+        """Collects relation state configuration for pod spec assembly.
+
+        Returns:
+            Dict[str, Any]: relation state information.
+        """
+        relation_state = {
+            "message_host": self.state.message_host,
+            "message_port": self.state.message_port,
+            "database_uri": self.state.database_uri,
+            "prometheus_host": self.state.prometheus_host,
+            "prometheus_port": self.state.prometheus_port,
+        }
+
+        return relation_state
+
+    def configure_pod(self, event: EventBase) -> NoReturn:
+        """Assemble the pod spec and apply it, if possible.
+
+        Args:
+            event (EventBase): Hook or Relation event that started the
+                               function.
+        """
+        if missing := self._missing_relations():
+            self.unit.status = BlockedStatus(
+                "Waiting for {0} relation{1}".format(
+                    missing, "s" if "," in missing else ""
+                )
+            )
+            return
+
+        if not self.unit.is_leader():
+            self.unit.status = ActiveStatus("ready")
+            return
+
+        self.unit.status = MaintenanceStatus("Assembling pod spec")
+
+        # Fetch image information
+        try:
+            self.unit.status = MaintenanceStatus("Fetching image information")
+            image_info = self.image.fetch()
+        except OCIImageResourceError:
+            self.unit.status = BlockedStatus("Error fetching image information")
+            return
+
+        try:
+            pod_spec = make_pod_spec(
+                image_info,
+                self.model.config,
+                self.relation_state,
+                self.model.app.name,
+                self.port,
+            )
+        except ValidationError as exc:
+            LOGGER.exception("Config/Relation data validation error")
+            self.unit.status = BlockedStatus(str(exc))
+            return
+
+        if self.state.pod_spec != pod_spec:
+            self.model.pod.set_spec(pod_spec)
+            self.state.pod_spec = pod_spec
+
+        self.unit.status = ActiveStatus("ready")
+
+
+if __name__ == "__main__":
+    main(MonCharm)
diff --git a/installers/charm/mon/src/pod_spec.py b/installers/charm/mon/src/pod_spec.py
new file mode 100644
index 0000000..5c9182a
--- /dev/null
+++ b/installers/charm/mon/src/pod_spec.py
@@ -0,0 +1,204 @@
+#!/usr/bin/env python3
+# Copyright 2020 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
+##
+
+import logging
+from pydantic import BaseModel, constr, PositiveInt
+from typing import Any, Dict, List
+
+logger = logging.getLogger(__name__)
+
+
+class ConfigData(BaseModel):
+    """Configuration data model."""
+
+    openstack_default_granularity: PositiveInt
+    global_request_timeout: PositiveInt
+    log_level: constr(regex=r"^(INFO|DEBUG)$")
+    collector_interval: PositiveInt
+    evaluator_interval: PositiveInt
+    database_commonkey: constr(min_length=1)
+    vca_host: constr(min_length=1)
+    vca_user: constr(min_length=1)
+    vca_password: constr(min_length=1)
+    vca_cacert: str
+
+
+class RelationData(BaseModel):
+    """Relation data model."""
+
+    message_host: constr(min_length=1)
+    message_port: PositiveInt
+    database_uri: constr(regex=r"^(mongodb://)")
+    prometheus_host: constr(min_length=1)
+    prometheus_port: PositiveInt
+
+
+def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
+    """Generate pod ports details.
+
+    Args:
+        port (int): port to expose.
+
+    Returns:
+        List[Dict[str, Any]]: pod port details.
+    """
+    return [{"name": "mon", "containerPort": port, "protocol": "TCP"}]
+
+
+def _make_pod_envconfig(
+    config: Dict[str, Any], relation_state: Dict[str, Any]
+) -> Dict[str, Any]:
+    """Generate pod environment configuration.
+
+    Args:
+        config (Dict[str, Any]): configuration information.
+        relation_state (Dict[str, Any]): relation state information.
+
+    Returns:
+        Dict[str, Any]: pod environment configuration.
+    """
+    envconfig = {
+        # General configuration
+        "ALLOW_ANONYMOUS_LOGIN": "yes",
+        "OSMMON_OPENSTACK_DEFAULT_GRANULARITY": config["openstack_default_granularity"],
+        "OSMMON_GLOBAL_REQUEST_TIMEOUT": config["global_request_timeout"],
+        "OSMMON_GLOBAL_LOGLEVEL": config["log_level"],
+        "OSMMON_COLLECTOR_INTERVAL": config["collector_interval"],
+        "OSMMON_EVALUATOR_INTERVAL": config["evaluator_interval"],
+        # Kafka configuration
+        "OSMMON_MESSAGE_DRIVER": "kafka",
+        "OSMMON_MESSAGE_HOST": relation_state["message_host"],
+        "OSMMON_MESSAGE_PORT": relation_state["message_port"],
+        # Database configuration
+        "OSMMON_DATABASE_DRIVER": "mongo",
+        "OSMMON_DATABASE_URI": relation_state["database_uri"],
+        "OSMMON_DATABASE_COMMONKEY": config["database_commonkey"],
+        # Prometheus configuration
+        "OSMMON_PROMETHEUS_URL": f"http://{relation_state['prometheus_host']}:{relation_state['prometheus_port']}",
+        # VCA configuration
+        "OSMMON_VCA_HOST": config["vca_host"],
+        "OSMMON_VCA_USER": config["vca_user"],
+        "OSMMON_VCA_SECRET": config["vca_password"],
+        "OSMMON_VCA_CACERT": config["vca_cacert"],
+    }
+
+    return envconfig
+
+
+def _make_startup_probe() -> Dict[str, Any]:
+    """Generate startup probe.
+
+    Returns:
+        Dict[str, Any]: startup probe.
+    """
+    return {
+        "exec": {"command": ["/usr/bin/pgrep python3"]},
+        "initialDelaySeconds": 60,
+        "timeoutSeconds": 5,
+    }
+
+
+def _make_readiness_probe(port: int) -> Dict[str, Any]:
+    """Generate readiness probe.
+
+    Args:
+        port (int): [description]
+
+    Returns:
+        Dict[str, Any]: readiness probe.
+    """
+    return {
+        "tcpSocket": {
+            "port": port,
+        },
+        "periodSeconds": 10,
+        "timeoutSeconds": 5,
+        "successThreshold": 1,
+        "failureThreshold": 3,
+    }
+
+
+def _make_liveness_probe(port: int) -> Dict[str, Any]:
+    """Generate liveness probe.
+
+    Args:
+        port (int): [description]
+
+    Returns:
+        Dict[str, Any]: liveness probe.
+    """
+    return {
+        "tcpSocket": {
+            "port": port,
+        },
+        "initialDelaySeconds": 45,
+        "periodSeconds": 10,
+        "timeoutSeconds": 5,
+        "successThreshold": 1,
+        "failureThreshold": 3,
+    }
+
+
+def make_pod_spec(
+    image_info: Dict[str, str],
+    config: Dict[str, Any],
+    relation_state: Dict[str, Any],
+    app_name: str = "mon",
+    port: int = 8000,
+) -> Dict[str, Any]:
+    """Generate the pod spec information.
+
+    Args:
+        image_info (Dict[str, str]): Object provided by
+                                     OCIImageResource("image").fetch().
+        config (Dict[str, Any]): Configuration information.
+        relation_state (Dict[str, Any]): Relation state information.
+        app_name (str, optional): Application name. Defaults to "mon".
+        port (int, optional): Port for the container. Defaults to 8000.
+
+    Returns:
+        Dict[str, Any]: Pod spec dictionary for the charm.
+    """
+    if not image_info:
+        return None
+
+    ConfigData(**(config))
+    RelationData(**(relation_state))
+
+    ports = _make_pod_ports(port)
+    env_config = _make_pod_envconfig(config, relation_state)
+
+    return {
+        "version": 3,
+        "containers": [
+            {
+                "name": app_name,
+                "imageDetails": image_info,
+                "imagePullPolicy": "Always",
+                "ports": ports,
+                "envConfig": env_config,
+            }
+        ],
+        "kubernetesResources": {
+            "ingressResources": [],
+        },
+    }
diff --git a/installers/charm/mon/tests/__init__.py b/installers/charm/mon/tests/__init__.py
new file mode 100644
index 0000000..d0d973a
--- /dev/null
+++ b/installers/charm/mon/tests/__init__.py
@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+# Copyright 2020 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
+##
+
+"""Init mocking for unit tests."""
+
+import sys
+import mock
+
+sys.path.append("src")
+
+oci_image = mock.MagicMock()
+sys.modules["oci_image"] = oci_image
diff --git a/installers/charm/mon/tests/test_charm.py b/installers/charm/mon/tests/test_charm.py
new file mode 100644
index 0000000..5ea4efa
--- /dev/null
+++ b/installers/charm/mon/tests/test_charm.py
@@ -0,0 +1,326 @@
+#!/usr/bin/env python3
+# Copyright 2020 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
+##
+
+from typing import NoReturn
+import unittest
+from ops.model import BlockedStatus
+
+from ops.testing import Harness
+
+from charm import MonCharm
+
+
+class TestCharm(unittest.TestCase):
+    """MON Charm unit tests."""
+
+    def setUp(self) -> NoReturn:
+        """Test setup"""
+        self.harness = Harness(MonCharm)
+        self.harness.set_leader(is_leader=True)
+        self.harness.begin()
+
+    def test_on_start_without_relations(self) -> NoReturn:
+        """Test installation without any relation."""
+        self.harness.charm.on.start.emit()
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertIn("kafka", self.harness.charm.unit.status.message)
+        self.assertIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+    def test_on_start_with_relations(self) -> NoReturn:
+        """Test deployment without keystone."""
+        expected_result = {
+            "version": 3,
+            "containers": [
+                {
+                    "name": "mon",
+                    "imageDetails": self.harness.charm.image.fetch(),
+                    "imagePullPolicy": "Always",
+                    "ports": [
+                        {
+                            "name": "mon",
+                            "containerPort": 8000,
+                            "protocol": "TCP",
+                        }
+                    ],
+                    "envConfig": {
+                        "ALLOW_ANONYMOUS_LOGIN": "yes",
+                        "OSMMON_OPENSTACK_DEFAULT_GRANULARITY": 300,
+                        "OSMMON_GLOBAL_REQUEST_TIMEOUT": 10,
+                        "OSMMON_GLOBAL_LOGLEVEL": "INFO",
+                        "OSMMON_COLLECTOR_INTERVAL": 30,
+                        "OSMMON_EVALUATOR_INTERVAL": 30,
+                        "OSMMON_MESSAGE_DRIVER": "kafka",
+                        "OSMMON_MESSAGE_HOST": "kafka",
+                        "OSMMON_MESSAGE_PORT": 9092,
+                        "OSMMON_DATABASE_DRIVER": "mongo",
+                        "OSMMON_DATABASE_URI": "mongodb://mongo:27017",
+                        "OSMMON_DATABASE_COMMONKEY": "osm",
+                        "OSMMON_PROMETHEUS_URL": "http://prometheus:9090",
+                        "OSMMON_VCA_HOST": "admin",
+                        "OSMMON_VCA_USER": "admin",
+                        "OSMMON_VCA_SECRET": "secret",
+                        "OSMMON_VCA_CACERT": "",
+                    },
+                }
+            ],
+            "kubernetesResources": {"ingressResources": []},
+        }
+
+        self.harness.charm.on.start.emit()
+
+        # Check if kafka datastore is initialized
+        self.assertIsNone(self.harness.charm.state.message_host)
+        self.assertIsNone(self.harness.charm.state.message_port)
+
+        # Check if mongodb datastore is initialized
+        self.assertIsNone(self.harness.charm.state.database_uri)
+
+        # Check if prometheus datastore is initialized
+        self.assertIsNone(self.harness.charm.state.prometheus_host)
+        self.assertIsNone(self.harness.charm.state.prometheus_port)
+
+        # Initializing the kafka relation
+        kafka_relation_id = self.harness.add_relation("kafka", "kafka")
+        self.harness.add_relation_unit(kafka_relation_id, "kafka/0")
+        self.harness.update_relation_data(
+            kafka_relation_id, "kafka/0", {"host": "kafka", "port": 9092}
+        )
+
+        # Initializing the mongo relation
+        mongodb_relation_id = self.harness.add_relation("mongodb", "mongodb")
+        self.harness.add_relation_unit(mongodb_relation_id, "mongodb/0")
+        self.harness.update_relation_data(
+            mongodb_relation_id,
+            "mongodb/0",
+            {"connection_string": "mongodb://mongo:27017"},
+        )
+
+        # Initializing the prometheus relation
+        prometheus_relation_id = self.harness.add_relation("prometheus", "prometheus")
+        self.harness.add_relation_unit(prometheus_relation_id, "prometheus/0")
+        self.harness.update_relation_data(
+            prometheus_relation_id,
+            "prometheus/0",
+            {"hostname": "prometheus", "port": 9090},
+        )
+
+        # Checking if kafka data is stored
+        self.assertEqual(self.harness.charm.state.message_host, "kafka")
+        self.assertEqual(self.harness.charm.state.message_port, 9092)
+
+        # Checking if mongodb data is stored
+        self.assertEqual(self.harness.charm.state.database_uri, "mongodb://mongo:27017")
+
+        # Checking if prometheus data is stored
+        self.assertEqual(self.harness.charm.state.prometheus_host, "prometheus")
+        self.assertEqual(self.harness.charm.state.prometheus_port, 9090)
+
+        # Verifying status
+        self.assertNotIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        pod_spec, _ = self.harness.get_pod_spec()
+
+        self.assertDictEqual(expected_result, pod_spec)
+
+    def test_on_kafka_app_relation_changed(self) -> NoReturn:
+        """Test to see if kafka relation is updated."""
+        self.harness.charm.on.start.emit()
+
+        self.assertIsNone(self.harness.charm.state.message_host)
+        self.assertIsNone(self.harness.charm.state.message_port)
+
+        relation_id = self.harness.add_relation("kafka", "kafka")
+        self.harness.add_relation_unit(relation_id, "kafka/0")
+        self.harness.update_relation_data(
+            relation_id, "kafka", {"host": "kafka", "port": 9092}
+        )
+
+        self.assertEqual(self.harness.charm.state.message_host, "kafka")
+        self.assertEqual(self.harness.charm.state.message_port, 9092)
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertNotIn("kafka", self.harness.charm.unit.status.message)
+        self.assertIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+    def test_on_kafka_unit_relation_changed(self) -> NoReturn:
+        """Test to see if kafka relation is updated."""
+        self.harness.charm.on.start.emit()
+
+        self.assertIsNone(self.harness.charm.state.message_host)
+        self.assertIsNone(self.harness.charm.state.message_port)
+
+        relation_id = self.harness.add_relation("kafka", "kafka")
+        self.harness.add_relation_unit(relation_id, "kafka/0")
+        self.harness.update_relation_data(
+            relation_id, "kafka/0", {"host": "kafka", "port": 9092}
+        )
+
+        self.assertEqual(self.harness.charm.state.message_host, "kafka")
+        self.assertEqual(self.harness.charm.state.message_port, 9092)
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertNotIn("kafka", self.harness.charm.unit.status.message)
+        self.assertIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+    def test_on_mongodb_app_relation_changed(self) -> NoReturn:
+        """Test to see if mongodb relation is updated."""
+        self.harness.charm.on.start.emit()
+
+        self.assertIsNone(self.harness.charm.state.database_uri)
+
+        relation_id = self.harness.add_relation("mongodb", "mongodb")
+        self.harness.add_relation_unit(relation_id, "mongodb/0")
+        self.harness.update_relation_data(
+            relation_id, "mongodb", {"connection_string": "mongodb://mongo:27017"}
+        )
+
+        self.assertEqual(self.harness.charm.state.database_uri, "mongodb://mongo:27017")
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertIn("kafka", self.harness.charm.unit.status.message)
+        self.assertNotIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+    def test_on_mongodb_unit_relation_changed(self) -> NoReturn:
+        """Test to see if mongodb relation is updated."""
+        self.harness.charm.on.start.emit()
+
+        self.assertIsNone(self.harness.charm.state.database_uri)
+
+        relation_id = self.harness.add_relation("mongodb", "mongodb")
+        self.harness.add_relation_unit(relation_id, "mongodb/0")
+        self.harness.update_relation_data(
+            relation_id, "mongodb/0", {"connection_string": "mongodb://mongo:27017"}
+        )
+
+        self.assertEqual(self.harness.charm.state.database_uri, "mongodb://mongo:27017")
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertIn("kafka", self.harness.charm.unit.status.message)
+        self.assertNotIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+    def test_on_prometheus_app_relation_changed(self) -> NoReturn:
+        """Test to see if prometheus relation is updated."""
+        self.harness.charm.on.start.emit()
+
+        self.assertIsNone(self.harness.charm.state.prometheus_host)
+        self.assertIsNone(self.harness.charm.state.prometheus_port)
+
+        relation_id = self.harness.add_relation("prometheus", "prometheus")
+        self.harness.add_relation_unit(relation_id, "prometheus/0")
+        self.harness.update_relation_data(
+            relation_id, "prometheus", {"hostname": "prometheus", "port": 9090}
+        )
+
+        self.assertEqual(self.harness.charm.state.prometheus_host, "prometheus")
+        self.assertEqual(self.harness.charm.state.prometheus_port, 9090)
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertIn("kafka", self.harness.charm.unit.status.message)
+        self.assertIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertNotIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+    def test_on_prometheus_unit_relation_changed(self) -> NoReturn:
+        """Test to see if prometheus relation is updated."""
+        self.harness.charm.on.start.emit()
+
+        self.assertIsNone(self.harness.charm.state.prometheus_host)
+        self.assertIsNone(self.harness.charm.state.prometheus_port)
+
+        relation_id = self.harness.add_relation("prometheus", "prometheus")
+        self.harness.add_relation_unit(relation_id, "prometheus/0")
+        self.harness.update_relation_data(
+            relation_id, "prometheus/0", {"hostname": "prometheus", "port": 9090}
+        )
+
+        self.assertEqual(self.harness.charm.state.prometheus_host, "prometheus")
+        self.assertEqual(self.harness.charm.state.prometheus_port, 9090)
+
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+        # Verifying status message
+        self.assertGreater(len(self.harness.charm.unit.status.message), 0)
+        self.assertTrue(
+            self.harness.charm.unit.status.message.startswith("Waiting for ")
+        )
+        self.assertIn("kafka", self.harness.charm.unit.status.message)
+        self.assertIn("mongodb", self.harness.charm.unit.status.message)
+        self.assertNotIn("prometheus", self.harness.charm.unit.status.message)
+        self.assertTrue(self.harness.charm.unit.status.message.endswith(" relations"))
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/installers/charm/mon/tests/test_pod_spec.py b/installers/charm/mon/tests/test_pod_spec.py
new file mode 100644
index 0000000..eff2713
--- /dev/null
+++ b/installers/charm/mon/tests/test_pod_spec.py
@@ -0,0 +1,294 @@
+#!/usr/bin/env python3
+# Copyright 2020 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
+##
+
+from pydantic import ValidationError
+from typing import NoReturn
+import unittest
+
+import pod_spec
+
+
+class TestPodSpec(unittest.TestCase):
+    """Pod spec unit tests."""
+
+    def test_make_pod_ports(self) -> NoReturn:
+        """Testing make pod ports."""
+        port = 8000
+
+        expected_result = [
+            {
+                "name": "mon",
+                "containerPort": port,
+                "protocol": "TCP",
+            }
+        ]
+
+        pod_ports = pod_spec._make_pod_ports(port)
+
+        self.assertListEqual(expected_result, pod_ports)
+
+    def test_make_pod_envconfig(self) -> NoReturn:
+        """Testing make pod envconfig."""
+        config = {
+            "openstack_default_granularity": 300,
+            "global_request_timeout": 10,
+            "log_level": "INFO",
+            "database_commonkey": "osm",
+            "collector_interval": 30,
+            "evaluator_interval": 30,
+            "vca_host": "admin",
+            "vca_user": "admin",
+            "vca_password": "secret",
+            "vca_cacert": "",
+        }
+        relation_state = {
+            "message_host": "kafka",
+            "message_port": 9090,
+            "database_uri": "mongodb://mongo",
+            "prometheus_host": "prometheus",
+            "prometheus_port": 9082,
+        }
+
+        expected_result = {
+            "ALLOW_ANONYMOUS_LOGIN": "yes",
+            "OSMMON_OPENSTACK_DEFAULT_GRANULARITY": config[
+                "openstack_default_granularity"
+            ],
+            "OSMMON_GLOBAL_REQUEST_TIMEOUT": config["global_request_timeout"],
+            "OSMMON_GLOBAL_LOGLEVEL": config["log_level"],
+            "OSMMON_COLLECTOR_INTERVAL": config["collector_interval"],
+            "OSMMON_EVALUATOR_INTERVAL": config["evaluator_interval"],
+            "OSMMON_MESSAGE_DRIVER": "kafka",
+            "OSMMON_MESSAGE_HOST": relation_state["message_host"],
+            "OSMMON_MESSAGE_PORT": relation_state["message_port"],
+            "OSMMON_DATABASE_DRIVER": "mongo",
+            "OSMMON_DATABASE_URI": relation_state["database_uri"],
+            "OSMMON_DATABASE_COMMONKEY": config["database_commonkey"],
+            "OSMMON_PROMETHEUS_URL": f"http://{relation_state['prometheus_host']}:{relation_state['prometheus_port']}",
+            "OSMMON_VCA_HOST": config["vca_host"],
+            "OSMMON_VCA_USER": config["vca_user"],
+            "OSMMON_VCA_SECRET": config["vca_password"],
+            "OSMMON_VCA_CACERT": config["vca_cacert"],
+        }
+
+        pod_envconfig = pod_spec._make_pod_envconfig(config, relation_state)
+
+        self.assertDictEqual(expected_result, pod_envconfig)
+
+    def test_make_startup_probe(self) -> NoReturn:
+        """Testing make startup probe."""
+        expected_result = {
+            "exec": {"command": ["/usr/bin/pgrep python3"]},
+            "initialDelaySeconds": 60,
+            "timeoutSeconds": 5,
+        }
+
+        startup_probe = pod_spec._make_startup_probe()
+
+        self.assertDictEqual(expected_result, startup_probe)
+
+    def test_make_readiness_probe(self) -> NoReturn:
+        """Testing make readiness probe."""
+        port = 8000
+
+        expected_result = {
+            "tcpSocket": {
+                "port": port,
+            },
+            "periodSeconds": 10,
+            "timeoutSeconds": 5,
+            "successThreshold": 1,
+            "failureThreshold": 3,
+        }
+
+        readiness_probe = pod_spec._make_readiness_probe(port)
+
+        self.assertDictEqual(expected_result, readiness_probe)
+
+    def test_make_liveness_probe(self) -> NoReturn:
+        """Testing make liveness probe."""
+        port = 8000
+
+        expected_result = {
+            "tcpSocket": {
+                "port": port,
+            },
+            "initialDelaySeconds": 45,
+            "periodSeconds": 10,
+            "timeoutSeconds": 5,
+            "successThreshold": 1,
+            "failureThreshold": 3,
+        }
+
+        liveness_probe = pod_spec._make_liveness_probe(port)
+
+        self.assertDictEqual(expected_result, liveness_probe)
+
+    def test_make_pod_spec(self) -> NoReturn:
+        """Testing make pod spec."""
+        image_info = {"upstream-source": "opensourcemano/mon:8"}
+        config = {
+            "site_url": "",
+            "openstack_default_granularity": 300,
+            "global_request_timeout": 10,
+            "log_level": "INFO",
+            "database_commonkey": "osm",
+            "collector_interval": 30,
+            "evaluator_interval": 30,
+            "vca_host": "admin",
+            "vca_user": "admin",
+            "vca_password": "secret",
+            "vca_cacert": "",
+        }
+        relation_state = {
+            "message_host": "kafka",
+            "message_port": 9090,
+            "database_uri": "mongodb://mongo",
+            "prometheus_host": "prometheus",
+            "prometheus_port": 9082,
+        }
+        app_name = "mon"
+        port = 8000
+
+        expected_result = {
+            "version": 3,
+            "containers": [
+                {
+                    "name": app_name,
+                    "imageDetails": image_info,
+                    "imagePullPolicy": "Always",
+                    "ports": [
+                        {
+                            "name": app_name,
+                            "containerPort": port,
+                            "protocol": "TCP",
+                        }
+                    ],
+                    "envConfig": {
+                        "ALLOW_ANONYMOUS_LOGIN": "yes",
+                        "OSMMON_OPENSTACK_DEFAULT_GRANULARITY": config[
+                            "openstack_default_granularity"
+                        ],
+                        "OSMMON_GLOBAL_REQUEST_TIMEOUT": config[
+                            "global_request_timeout"
+                        ],
+                        "OSMMON_GLOBAL_LOGLEVEL": config["log_level"],
+                        "OSMMON_COLLECTOR_INTERVAL": config["collector_interval"],
+                        "OSMMON_EVALUATOR_INTERVAL": config["evaluator_interval"],
+                        "OSMMON_MESSAGE_DRIVER": "kafka",
+                        "OSMMON_MESSAGE_HOST": relation_state["message_host"],
+                        "OSMMON_MESSAGE_PORT": relation_state["message_port"],
+                        "OSMMON_DATABASE_DRIVER": "mongo",
+                        "OSMMON_DATABASE_URI": relation_state["database_uri"],
+                        "OSMMON_DATABASE_COMMONKEY": config["database_commonkey"],
+                        "OSMMON_PROMETHEUS_URL": f"http://{relation_state['prometheus_host']}:{relation_state['prometheus_port']}",
+                        "OSMMON_VCA_HOST": config["vca_host"],
+                        "OSMMON_VCA_USER": config["vca_user"],
+                        "OSMMON_VCA_SECRET": config["vca_password"],
+                        "OSMMON_VCA_CACERT": config["vca_cacert"],
+                    },
+                }
+            ],
+            "kubernetesResources": {"ingressResources": []},
+        }
+
+        spec = pod_spec.make_pod_spec(
+            image_info, config, relation_state, app_name, port
+        )
+
+        self.assertDictEqual(expected_result, spec)
+
+    def test_make_pod_spec_without_image_info(self) -> NoReturn:
+        """Testing make pod spec without image_info."""
+        image_info = None
+        config = {
+            "site_url": "",
+            "openstack_default_granularity": 300,
+            "global_request_timeout": 10,
+            "log_level": "INFO",
+            "database_commonkey": "osm",
+            "collector_interval": 30,
+            "evaluator_interval": 30,
+            "vca_host": "admin",
+            "vca_user": "admin",
+            "vca_password": "secret",
+            "vca_cacert": "",
+        }
+        relation_state = {
+            "message_host": "kafka",
+            "message_port": 9090,
+            "database_uri": "mongodb://mongo",
+            "prometheus_host": "prometheus",
+            "prometheus_port": 9082,
+        }
+        app_name = "mon"
+        port = 8000
+
+        spec = pod_spec.make_pod_spec(
+            image_info, config, relation_state, app_name, port
+        )
+
+        self.assertIsNone(spec)
+
+    def test_make_pod_spec_without_config(self) -> NoReturn:
+        """Testing make pod spec without config."""
+        image_info = {"upstream-source": "opensourcemano/mon:8"}
+        config = {}
+        relation_state = {
+            "message_host": "kafka",
+            "message_port": 9090,
+            "database_uri": "mongodb://mongo",
+            "prometheus_host": "prometheus",
+            "prometheus_port": 9082,
+        }
+        app_name = "mon"
+        port = 8000
+
+        with self.assertRaises(ValidationError):
+            pod_spec.make_pod_spec(image_info, config, relation_state, app_name, port)
+
+    def test_make_pod_spec_without_relation_state(self) -> NoReturn:
+        """Testing make pod spec without relation_state."""
+        image_info = {"upstream-source": "opensourcemano/mon:8"}
+        config = {
+            "site_url": "",
+            "openstack_default_granularity": 300,
+            "global_request_timeout": 10,
+            "log_level": "INFO",
+            "database_commonkey": "osm",
+            "collector_interval": 30,
+            "evaluator_interval": 30,
+            "vca_host": "admin",
+            "vca_user": "admin",
+            "vca_password": "secret",
+            "vca_cacert": "",
+        }
+        relation_state = {}
+        app_name = "mon"
+        port = 8000
+
+        with self.assertRaises(ValidationError):
+            pod_spec.make_pod_spec(image_info, config, relation_state, app_name, port)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/installers/charm/mon/tox.ini b/installers/charm/mon/tox.ini
new file mode 100644
index 0000000..7ab02dd
--- /dev/null
+++ b/installers/charm/mon/tox.ini
@@ -0,0 +1,82 @@
+# Copyright 2020 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
+envlist = unit, lint
+sitepackages = False
+skip_missing_interpreters = False
+
+[testenv]
+basepython = python3
+setenv =
+  PYTHONHASHSEED=0
+  PYTHONPATH = {toxinidir}/src
+  CHARM_NAME = mon
+
+[testenv:build]
+passenv=HTTP_PROXY HTTPS_PROXY NO_PROXY
+whitelist_externals =
+  charmcraft
+  rm
+  unzip
+commands =
+  rm -rf release mon.charm
+  charmcraft build
+  unzip mon.charm -d release
+
+[testenv:unit]
+commands =
+  coverage erase
+  stestr run --slowest --test-path=./tests --top-dir=./
+  coverage combine
+  coverage html -d cover
+  coverage xml -o cover/coverage.xml
+  coverage report
+deps =
+  coverage
+  stestr
+  mock
+  ops
+  pydantic
+setenv =
+  {[testenv]setenv}
+  PYTHON=coverage run
+
+[testenv:lint]
+deps =
+  black
+  yamllint
+  flake8
+commands =
+  black --check --diff . --exclude "build/|.tox/|mod/|lib/"
+  yamllint .
+  flake8 . --max-line-length=100 --ignore="E501,W503,W504,F722" --exclude "build/ .tox/ mod/ lib/"
+
+[coverage:run]
+branch = True
+concurrency = multiprocessing
+parallel = True
+source =
+  .
+omit =  
+  .tox/*
+  tests/*