Major improvement in OSM charms

- Adapt all new operator charms to use the same pattern. They are all
using now this library that encapsulates the common logic for all
charms: https://github.com/davigar15/ops-lib-charmed-osm. That will be
eventually moved to gitlab, when it has a PyPI repository available
- Add unit tests to all charms
- Modify installer and bundles to point to the new charms
- Improve the build.sh script for building the charms

Change-Id: I0896ceb082d1b6a76b3560c07482a4135a220a3f
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/prometheus/.gitignore b/installers/charm/prometheus/.gitignore
index bf04eb4..2885df2 100644
--- a/installers/charm/prometheus/.gitignore
+++ b/installers/charm/prometheus/.gitignore
@@ -22,7 +22,9 @@
 venv
 .vscode
 build
-prometheus.charm
+*.charm
 .coverage
+coverage.xml
 .stestr
 cover
+release
\ No newline at end of file
diff --git a/installers/charm/prometheus/.jujuignore b/installers/charm/prometheus/.jujuignore
new file mode 100644
index 0000000..bf04eb4
--- /dev/null
+++ b/installers/charm/prometheus/.jujuignore
@@ -0,0 +1,28 @@
+# Copyright 2021 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
+prometheus.charm
+.coverage
+.stestr
+cover
diff --git a/installers/charm/prometheus/.yamllint.yaml b/installers/charm/prometheus/.yamllint.yaml
index f3ecd3a..d71fb69 100644
--- a/installers/charm/prometheus/.yamllint.yaml
+++ b/installers/charm/prometheus/.yamllint.yaml
@@ -28,6 +28,7 @@
   - ".yamllint"
 ignore: |
   .tox
+  cover/
   build/
-  mod/
-  lib/
+  venv
+  release/
diff --git a/installers/charm/prometheus/config.yaml b/installers/charm/prometheus/config.yaml
index baa04cd..d953de3 100644
--- a/installers/charm/prometheus/config.yaml
+++ b/installers/charm/prometheus/config.yaml
@@ -20,11 +20,11 @@
 ##
 
 options:
-  web_subpath:
+  web-subpath:
     description: Subpath for accessing Prometheus
     type: string
     default: /
-  default_target:
+  default-target:
     description: Default target to be added in Prometheus
     type: string
     default: ""
diff --git a/installers/charm/prometheus/metadata.yaml b/installers/charm/prometheus/metadata.yaml
index 960904b..f021418 100644
--- a/installers/charm/prometheus/metadata.yaml
+++ b/installers/charm/prometheus/metadata.yaml
@@ -41,3 +41,7 @@
 provides:
   prometheus:
     interface: prometheus
+storage:
+  data:
+    type: filesystem
+    location: /prometheus
diff --git a/installers/charm/prometheus/requirements-test.txt b/installers/charm/prometheus/requirements-test.txt
new file mode 100644
index 0000000..d7585f3
--- /dev/null
+++ b/installers/charm/prometheus/requirements-test.txt
@@ -0,0 +1,31 @@
+# Copyright 2021 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
+##
+-r requirements.txt
+coverage
+stestr
+mock
+black
+yamllint
+flake8
+safety
+requests-mock
+asynctest
+nose2
\ No newline at end of file
diff --git a/installers/charm/prometheus/requirements.txt b/installers/charm/prometheus/requirements.txt
index 884cf9f..f10a199 100644
--- a/installers/charm/prometheus/requirements.txt
+++ b/installers/charm/prometheus/requirements.txt
@@ -19,5 +19,4 @@
 # osm-charmers@lists.launchpad.net
 ##
 
-ops
-git+https://github.com/juju-solutions/resource-oci-image/@c5778285d332edf3d9a538f9d0c06154b7ec1b0b#egg=oci-image
+git+https://github.com/davigar15/ops-lib-charmed-osm/@e7f26cd29b322e175a23cadbe4546b7f2bbf111c
\ No newline at end of file
diff --git a/installers/charm/prometheus/src/charm.py b/installers/charm/prometheus/src/charm.py
index 4371d47..3d72cac 100755
--- a/installers/charm/prometheus/src/charm.py
+++ b/installers/charm/prometheus/src/charm.py
@@ -20,175 +20,181 @@
 # osm-charmers@lists.launchpad.net
 ##
 
+# pylint: disable=E0213
+
 import logging
-from typing import Dict, List, NoReturn
+from typing import Optional, NoReturn
+from ipaddress import ip_network
 
-from ops.charm import CharmBase
-from ops.framework import EventBase, StoredState
+from ops.framework import EventBase
 from ops.main import main
-from ops.model import ActiveStatus, Application, BlockedStatus, MaintenanceStatus, Unit
-from oci_image import OCIImageResource, OCIImageResourceError
 
-from pod_spec import make_pod_spec
+from opslib.osm.charm import CharmedOsmBase
+
+from opslib.osm.pod import (
+    IngressResourceV3Builder,
+    FilesV3Builder,
+    ContainerV3Builder,
+    PodSpecV3Builder,
+)
+
+
+from opslib.osm.validator import (
+    ModelValidator,
+    validator,
+)
+
+from opslib.osm.interfaces.prometheus import PrometheusServer
+from urllib.parse import urlparse
 
 logger = logging.getLogger(__name__)
 
-PROMETHEUS_PORT = 9090
+PORT = 9090
 
 
-class RelationsMissing(Exception):
-    def __init__(self, missing_relations: List):
-        self.message = ""
-        if missing_relations and isinstance(missing_relations, list):
-            self.message += f'Waiting for {", ".join(missing_relations)} relation'
-            if "," in self.message:
-                self.message += "s"
+class ConfigModel(ModelValidator):
+    web_subpath: str
+    default_target: str
+    max_file_size: int
+    site_url: Optional[str]
+    ingress_whitelist_source_range: Optional[str]
+    tls_secret_name: Optional[str]
+    enable_web_admin_api: bool
+
+    @validator("web_subpath")
+    def validate_web_subpath(cls, v):
+        if len(v) < 1:
+            raise ValueError("web-subpath must be a non-empty string")
+        return v
+
+    @validator("max_file_size")
+    def validate_max_file_size(cls, v):
+        if v < 0:
+            raise ValueError("value must be equal or greater than 0")
+        return v
+
+    @validator("site_url")
+    def validate_site_url(cls, v):
+        if v:
+            parsed = urlparse(v)
+            if not parsed.scheme.startswith("http"):
+                raise ValueError("value must start with http")
+        return v
+
+    @validator("ingress_whitelist_source_range")
+    def validate_ingress_whitelist_source_range(cls, v):
+        if v:
+            ip_network(v)
+        return v
 
 
-class RelationDefinition:
-    def __init__(self, relation_name: str, keys: List, source_type):
-        if source_type != Application and source_type != Unit:
-            raise TypeError(
-                "source_type should be ops.model.Application or ops.model.Unit"
-            )
-        self.relation_name = relation_name
-        self.keys = keys
-        self.source_type = source_type
+class PrometheusCharm(CharmedOsmBase):
 
-
-def check_missing_relation_data(
-    data: Dict,
-    expected_relations_data: List[RelationDefinition],
-):
-    missing_relations = []
-    for relation_data in expected_relations_data:
-        if not all(
-            f"{relation_data.relation_name}_{k}" in data for k in relation_data.keys
-        ):
-            missing_relations.append(relation_data.relation_name)
-    if missing_relations:
-        raise RelationsMissing(missing_relations)
-
-
-def get_relation_data(
-    charm: CharmBase,
-    relation_data: RelationDefinition,
-) -> Dict:
-    data = {}
-    relation = charm.model.get_relation(relation_data.relation_name)
-    if relation:
-        self_app_unit = (
-            charm.app if relation_data.source_type == Application else charm.unit
-        )
-        expected_type = relation_data.source_type
-        for app_unit in relation.data:
-            if app_unit != self_app_unit and isinstance(app_unit, expected_type):
-                if all(k in relation.data[app_unit] for k in relation_data.keys):
-                    for k in relation_data.keys:
-                        data[f"{relation_data.relation_name}_{k}"] = relation.data[
-                            app_unit
-                        ].get(k)
-                    break
-    return data
-
-
-class PrometheusCharm(CharmBase):
     """Prometheus Charm."""
 
-    state = StoredState()
-
     def __init__(self, *args) -> NoReturn:
         """Prometheus Charm constructor."""
-        super().__init__(*args)
-
-        # Internal state initialization
-        self.state.set_default(pod_spec=None)
-
-        self.port = PROMETHEUS_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)
+        super().__init__(*args, oci_image="image")
 
         # Registering provided relation events
+        self.prometheus = PrometheusServer(self, "prometheus")
         self.framework.observe(
-            self.on.prometheus_relation_joined, self._publish_prometheus_info
+            self.on.prometheus_relation_joined,  # pylint: disable=E1101
+            self._publish_prometheus_info,
         )
 
     def _publish_prometheus_info(self, event: EventBase) -> NoReturn:
-        """Publishes Prometheus information.
+        self.prometheus.publish_info(self.app.name, PORT)
 
-        Args:
-            event (EventBase): Prometheus relation event.
-        """
-        if self.unit.is_leader():
-            rel_data = {
-                "host": self.model.app.name,
-                "port": str(PROMETHEUS_PORT),
+    def _build_files(self, config: ConfigModel):
+        files_builder = FilesV3Builder()
+        files_builder.add_file(
+            "prometheus.yml",
+            (
+                "global:\n"
+                "  scrape_interval: 15s\n"
+                "  evaluation_interval: 15s\n"
+                "alerting:\n"
+                "  alertmanagers:\n"
+                "    - static_configs:\n"
+                "        - targets:\n"
+                "rule_files:\n"
+                "scrape_configs:\n"
+                "  - job_name: 'prometheus'\n"
+                "    static_configs:\n"
+                f"      - targets: [{config.default_target}]\n"
+            ),
+        )
+        return files_builder.build()
+
+    def build_pod_spec(self, image_info):
+        # Validate config
+        config = ConfigModel(**dict(self.config))
+        # Create Builder for the PodSpec
+        pod_spec_builder = PodSpecV3Builder()
+        # Build Container
+        container_builder = ContainerV3Builder(self.app.name, image_info)
+        container_builder.add_port(name=self.app.name, port=PORT)
+        container_builder.add_http_readiness_probe(
+            "/-/ready",
+            PORT,
+            initial_delay_seconds=10,
+            timeout_seconds=30,
+        )
+        container_builder.add_http_liveness_probe(
+            "/-/healthy",
+            PORT,
+            initial_delay_seconds=30,
+            period_seconds=30,
+        )
+        command = [
+            "/bin/prometheus",
+            "--config.file=/etc/prometheus/prometheus.yml",
+            "--storage.tsdb.path=/prometheus",
+            "--web.console.libraries=/usr/share/prometheus/console_libraries",
+            "--web.console.templates=/usr/share/prometheus/consoles",
+            f"--web.route-prefix={config.web_subpath}",
+            f"--web.external-url=http://localhost:{PORT}{config.web_subpath}",
+        ]
+        if config.enable_web_admin_api:
+            command.append("--web.enable-admin-api")
+        container_builder.add_command(command)
+        container_builder.add_volume_config(
+            "config", "/etc/prometheus", self._build_files(config)
+        )
+        container = container_builder.build()
+        # Add container to pod spec
+        pod_spec_builder.add_container(container)
+        # Add ingress resources to pod spec if site url exists
+        if config.site_url:
+            parsed = urlparse(config.site_url)
+            annotations = {
+                "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
+                    str(config.max_file_size) + "m"
+                    if config.max_file_size > 0
+                    else config.max_file_size
+                ),
             }
-            for k, v in rel_data.items():
-                event.relation.data[self.app][k] = v
-
-    @property
-    def relations_requirements(self):
-        return []
-
-    def get_relation_state(self):
-        relation_state = {}
-        for relation_requirements in self.relations_requirements:
-            data = get_relation_data(self, relation_requirements)
-            relation_state = {**relation_state, **data}
-        check_missing_relation_data(relation_state, self.relations_requirements)
-        return relation_state
-
-    def configure_pod(self, _=None) -> NoReturn:
-        """Assemble the pod spec and apply it, if possible.
-
-        Args:
-            event (EventBase): Hook or Relation event that started the
-                               function.
-        """
-        if not self.unit.is_leader():
-            self.unit.status = ActiveStatus("ready")
-            return
-
-        relation_state = None
-        try:
-            relation_state = self.get_relation_state()
-        except RelationsMissing as exc:
-            logger.exception("Relation missing error")
-            self.unit.status = BlockedStatus(exc.message)
-            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,
-                relation_state,
-                self.model.app.name,
-                self.port,
+            ingress_resource_builder = IngressResourceV3Builder(
+                f"{self.app.name}-ingress", annotations
             )
-        except ValueError 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
+            if config.ingress_whitelist_source_range:
+                annotations[
+                    "nginx.ingress.kubernetes.io/whitelist-source-range"
+                ] = config.ingress_whitelist_source_range
 
-        self.unit.status = ActiveStatus("ready")
+            if parsed.scheme == "https":
+                ingress_resource_builder.add_tls(
+                    [parsed.hostname], config.tls_secret_name
+                )
+            else:
+                annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
+
+            ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
+            ingress_resource = ingress_resource_builder.build()
+            pod_spec_builder.add_ingress_resource(ingress_resource)
+        return pod_spec_builder.build()
 
 
 if __name__ == "__main__":
diff --git a/installers/charm/prometheus/tests/test_charm.py b/installers/charm/prometheus/tests/test_charm.py
index 87d7bc5..b1848bd 100644
--- a/installers/charm/prometheus/tests/test_charm.py
+++ b/installers/charm/prometheus/tests/test_charm.py
@@ -20,10 +20,10 @@
 # osm-charmers@lists.launchpad.net
 ##
 
+import sys
 from typing import NoReturn
 import unittest
-
-from ops.model import BlockedStatus
+from ops.model import ActiveStatus
 from ops.testing import Harness
 
 from charm import PrometheusCharm
@@ -34,445 +34,63 @@
 
     def setUp(self) -> NoReturn:
         """Test setup"""
+        self.image_info = sys.modules["oci_image"].OCIImageResource().fetch()
         self.harness = Harness(PrometheusCharm)
         self.harness.set_leader(is_leader=True)
         self.harness.begin()
+        self.config = {
+            "web-subpath": "/",
+            "default-target": "",
+            "max_file_size": 0,
+            "ingress_whitelist_source_range": "",
+            "tls_secret_name": "",
+            "site_url": "https://prometheus.192.168.100.100.xip.io",
+            "enable_web_admin_api": False,
+        }
+        self.harness.update_config(self.config)
 
-    def test_ingress_resources_without_http(self) -> NoReturn:
+    def test_config_changed(
+        self,
+    ) -> NoReturn:
         """Test ingress resources without HTTP."""
-        expected_result = {
-            "version": 3,
-            "containers": [
-                {
-                    "name": "prometheus",
-                    "imageDetails": self.harness.charm.image.fetch(),
-                    "imagePullPolicy": "Always",
-                    "ports": [
-                        {
-                            "name": "prometheus",
-                            "containerPort": 9090,
-                            "protocol": "TCP",
-                        }
-                    ],
-                    "envConfig": {},
-                    "volumeConfig": [
-                        {
-                            "name": "config",
-                            "mountPath": "/etc/prometheus",
-                            "files": [
-                                {
-                                    "path": "prometheus.yml",
-                                    "content": (
-                                        "global:\n"
-                                        "  scrape_interval: 15s\n"
-                                        "  evaluation_interval: 15s\n"
-                                        "alerting:\n"
-                                        "  alertmanagers:\n"
-                                        "    - static_configs:\n"
-                                        "        - targets:\n"
-                                        "rule_files:\n"
-                                        "scrape_configs:\n"
-                                        "  - job_name: 'prometheus'\n"
-                                        "    static_configs:\n"
-                                        "      - targets: [{}]\n".format("")
-                                    ),
-                                }
-                            ],
-                        }
-                    ],
-                    "command": [
-                        "/bin/prometheus",
-                        "--config.file=/etc/prometheus/prometheus.yml",
-                        "--storage.tsdb.path=/prometheus",
-                        "--web.console.libraries=/usr/share/prometheus/console_libraries",
-                        "--web.console.templates=/usr/share/prometheus/consoles",
-                        "--web.route-prefix={}".format("/"),
-                        "--web.external-url=http://localhost:{}{}".format(9090, "/"),
-                    ],
-                    "kubernetes": {
-                        "readinessProbe": {
-                            "httpGet": {
-                                "path": "/-/ready",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 10,
-                            "timeoutSeconds": 30,
-                        },
-                        "livenessProbe": {
-                            "httpGet": {
-                                "path": "/-/healthy",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 30,
-                            "periodSeconds": 30,
-                        },
-                    },
-                }
-            ],
-            "kubernetesResources": {"ingressResources": []},
-        }
 
-        self.harness.charm.on.start.emit()
+        self.harness.charm.on.config_changed.emit()
 
-        # Verifying status
-        self.assertNotIsInstance(self.harness.charm.unit.status, BlockedStatus)
+        # Assertions
+        self.assertIsInstance(self.harness.charm.unit.status, ActiveStatus)
 
-        pod_spec, _ = self.harness.get_pod_spec()
+    def test_config_changed_non_leader(
+        self,
+    ) -> NoReturn:
+        """Test ingress resources without HTTP."""
+        self.harness.set_leader(is_leader=False)
+        self.harness.charm.on.config_changed.emit()
 
-        self.assertDictEqual(expected_result, pod_spec)
+        # Assertions
+        self.assertIsInstance(self.harness.charm.unit.status, ActiveStatus)
 
-    def test_ingress_resources_with_http(self) -> NoReturn:
-        """Test ingress resources with HTTP."""
-        expected_result = {
-            "version": 3,
-            "containers": [
-                {
-                    "name": "prometheus",
-                    "imageDetails": self.harness.charm.image.fetch(),
-                    "imagePullPolicy": "Always",
-                    "ports": [
-                        {
-                            "name": "prometheus",
-                            "containerPort": 9090,
-                            "protocol": "TCP",
-                        }
-                    ],
-                    "envConfig": {},
-                    "volumeConfig": [
-                        {
-                            "name": "config",
-                            "mountPath": "/etc/prometheus",
-                            "files": [
-                                {
-                                    "path": "prometheus.yml",
-                                    "content": (
-                                        "global:\n"
-                                        "  scrape_interval: 15s\n"
-                                        "  evaluation_interval: 15s\n"
-                                        "alerting:\n"
-                                        "  alertmanagers:\n"
-                                        "    - static_configs:\n"
-                                        "        - targets:\n"
-                                        "rule_files:\n"
-                                        "scrape_configs:\n"
-                                        "  - job_name: 'prometheus'\n"
-                                        "    static_configs:\n"
-                                        "      - targets: [{}]\n".format("")
-                                    ),
-                                }
-                            ],
-                        }
-                    ],
-                    "command": [
-                        "/bin/prometheus",
-                        "--config.file=/etc/prometheus/prometheus.yml",
-                        "--storage.tsdb.path=/prometheus",
-                        "--web.console.libraries=/usr/share/prometheus/console_libraries",
-                        "--web.console.templates=/usr/share/prometheus/consoles",
-                        "--web.route-prefix={}".format("/"),
-                        "--web.external-url=http://localhost:{}{}".format(9090, "/"),
-                    ],
-                    "kubernetes": {
-                        "readinessProbe": {
-                            "httpGet": {
-                                "path": "/-/ready",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 10,
-                            "timeoutSeconds": 30,
-                        },
-                        "livenessProbe": {
-                            "httpGet": {
-                                "path": "/-/healthy",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 30,
-                            "periodSeconds": 30,
-                        },
-                    },
-                }
-            ],
-            "kubernetesResources": {
-                "ingressResources": [
-                    {
-                        "name": "prometheus-ingress",
-                        "annotations": {
-                            "nginx.ingress.kubernetes.io/proxy-body-size": "0",
-                            "nginx.ingress.kubernetes.io/ssl-redirect": "false",
-                        },
-                        "spec": {
-                            "rules": [
-                                {
-                                    "host": "prometheus",
-                                    "http": {
-                                        "paths": [
-                                            {
-                                                "path": "/",
-                                                "backend": {
-                                                    "serviceName": "prometheus",
-                                                    "servicePort": 9090,
-                                                },
-                                            }
-                                        ]
-                                    },
-                                }
-                            ]
-                        },
-                    }
-                ],
-            },
-        }
-
-        self.harness.charm.on.start.emit()
-
-        self.harness.update_config({"site_url": "http://prometheus"})
-
-        pod_spec, _ = self.harness.get_pod_spec()
-
-        self.assertDictEqual(expected_result, pod_spec)
-
-    def test_ingress_resources_with_https(self) -> NoReturn:
-        """Test ingress resources with HTTPS."""
-        expected_result = {
-            "version": 3,
-            "containers": [
-                {
-                    "name": "prometheus",
-                    "imageDetails": self.harness.charm.image.fetch(),
-                    "imagePullPolicy": "Always",
-                    "ports": [
-                        {
-                            "name": "prometheus",
-                            "containerPort": 9090,
-                            "protocol": "TCP",
-                        }
-                    ],
-                    "envConfig": {},
-                    "volumeConfig": [
-                        {
-                            "name": "config",
-                            "mountPath": "/etc/prometheus",
-                            "files": [
-                                {
-                                    "path": "prometheus.yml",
-                                    "content": (
-                                        "global:\n"
-                                        "  scrape_interval: 15s\n"
-                                        "  evaluation_interval: 15s\n"
-                                        "alerting:\n"
-                                        "  alertmanagers:\n"
-                                        "    - static_configs:\n"
-                                        "        - targets:\n"
-                                        "rule_files:\n"
-                                        "scrape_configs:\n"
-                                        "  - job_name: 'prometheus'\n"
-                                        "    static_configs:\n"
-                                        "      - targets: [{}]\n".format("")
-                                    ),
-                                }
-                            ],
-                        }
-                    ],
-                    "command": [
-                        "/bin/prometheus",
-                        "--config.file=/etc/prometheus/prometheus.yml",
-                        "--storage.tsdb.path=/prometheus",
-                        "--web.console.libraries=/usr/share/prometheus/console_libraries",
-                        "--web.console.templates=/usr/share/prometheus/consoles",
-                        "--web.route-prefix={}".format("/"),
-                        "--web.external-url=http://localhost:{}{}".format(9090, "/"),
-                    ],
-                    "kubernetes": {
-                        "readinessProbe": {
-                            "httpGet": {
-                                "path": "/-/ready",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 10,
-                            "timeoutSeconds": 30,
-                        },
-                        "livenessProbe": {
-                            "httpGet": {
-                                "path": "/-/healthy",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 30,
-                            "periodSeconds": 30,
-                        },
-                    },
-                }
-            ],
-            "kubernetesResources": {
-                "ingressResources": [
-                    {
-                        "name": "prometheus-ingress",
-                        "annotations": {
-                            "nginx.ingress.kubernetes.io/proxy-body-size": "0",
-                        },
-                        "spec": {
-                            "rules": [
-                                {
-                                    "host": "prometheus",
-                                    "http": {
-                                        "paths": [
-                                            {
-                                                "path": "/",
-                                                "backend": {
-                                                    "serviceName": "prometheus",
-                                                    "servicePort": 9090,
-                                                },
-                                            }
-                                        ]
-                                    },
-                                }
-                            ],
-                            "tls": [
-                                {"hosts": ["prometheus"], "secretName": "prometheus"}
-                            ],
-                        },
-                    }
-                ],
-            },
-        }
-
-        self.harness.charm.on.start.emit()
-
-        self.harness.update_config(
-            {"site_url": "https://prometheus", "tls_secret_name": "prometheus"}
-        )
-
-        pod_spec, _ = self.harness.get_pod_spec()
-
-        self.assertDictEqual(expected_result, pod_spec)
-
-    def test_ingress_resources_with_https_and_ingress_whitelist(self) -> NoReturn:
-        """Test ingress resources with HTTPS and ingress whitelist."""
-        expected_result = {
-            "version": 3,
-            "containers": [
-                {
-                    "name": "prometheus",
-                    "imageDetails": self.harness.charm.image.fetch(),
-                    "imagePullPolicy": "Always",
-                    "ports": [
-                        {
-                            "name": "prometheus",
-                            "containerPort": 9090,
-                            "protocol": "TCP",
-                        }
-                    ],
-                    "envConfig": {},
-                    "volumeConfig": [
-                        {
-                            "name": "config",
-                            "mountPath": "/etc/prometheus",
-                            "files": [
-                                {
-                                    "path": "prometheus.yml",
-                                    "content": (
-                                        "global:\n"
-                                        "  scrape_interval: 15s\n"
-                                        "  evaluation_interval: 15s\n"
-                                        "alerting:\n"
-                                        "  alertmanagers:\n"
-                                        "    - static_configs:\n"
-                                        "        - targets:\n"
-                                        "rule_files:\n"
-                                        "scrape_configs:\n"
-                                        "  - job_name: 'prometheus'\n"
-                                        "    static_configs:\n"
-                                        "      - targets: [{}]\n".format("")
-                                    ),
-                                }
-                            ],
-                        }
-                    ],
-                    "command": [
-                        "/bin/prometheus",
-                        "--config.file=/etc/prometheus/prometheus.yml",
-                        "--storage.tsdb.path=/prometheus",
-                        "--web.console.libraries=/usr/share/prometheus/console_libraries",
-                        "--web.console.templates=/usr/share/prometheus/consoles",
-                        "--web.route-prefix={}".format("/"),
-                        "--web.external-url=http://localhost:{}{}".format(9090, "/"),
-                    ],
-                    "kubernetes": {
-                        "readinessProbe": {
-                            "httpGet": {
-                                "path": "/-/ready",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 10,
-                            "timeoutSeconds": 30,
-                        },
-                        "livenessProbe": {
-                            "httpGet": {
-                                "path": "/-/healthy",
-                                "port": 9090,
-                            },
-                            "initialDelaySeconds": 30,
-                            "periodSeconds": 30,
-                        },
-                    },
-                }
-            ],
-            "kubernetesResources": {
-                "ingressResources": [
-                    {
-                        "name": "prometheus-ingress",
-                        "annotations": {
-                            "nginx.ingress.kubernetes.io/proxy-body-size": "0",
-                            "nginx.ingress.kubernetes.io/whitelist-source-range": "0.0.0.0/0",
-                        },
-                        "spec": {
-                            "rules": [
-                                {
-                                    "host": "prometheus",
-                                    "http": {
-                                        "paths": [
-                                            {
-                                                "path": "/",
-                                                "backend": {
-                                                    "serviceName": "prometheus",
-                                                    "servicePort": 9090,
-                                                },
-                                            }
-                                        ]
-                                    },
-                                }
-                            ],
-                            "tls": [
-                                {"hosts": ["prometheus"], "secretName": "prometheus"}
-                            ],
-                        },
-                    }
-                ],
-            },
-        }
-
-        self.harness.charm.on.start.emit()
-
-        self.harness.update_config(
-            {
-                "site_url": "https://prometheus",
-                "tls_secret_name": "prometheus",
-                "ingress_whitelist_source_range": "0.0.0.0/0",
-            }
-        )
-
-        pod_spec, _ = self.harness.get_pod_spec()
-
-        self.assertDictEqual(expected_result, pod_spec)
-
-    def test_publish_prometheus_info(self) -> NoReturn:
+    def test_publish_prometheus_info(
+        self,
+    ) -> NoReturn:
         """Test to see if prometheus relation is updated."""
         expected_result = {
-            "host": "prometheus",
+            "hostname": "prometheus",
             "port": "9090",
         }
 
-        self.harness.charm.on.start.emit()
+        relation_id = self.harness.add_relation("prometheus", "mon")
+        self.harness.add_relation_unit(relation_id, "mon/0")
+        relation_data = self.harness.get_relation_data(relation_id, "prometheus")
 
+        self.assertDictEqual(expected_result, relation_data)
+
+    def test_publish_prometheus_info_non_leader(
+        self,
+    ) -> NoReturn:
+        """Test to see if prometheus relation is updated."""
+        expected_result = {}
+
+        self.harness.set_leader(is_leader=False)
         relation_id = self.harness.add_relation("prometheus", "mon")
         self.harness.add_relation_unit(relation_id, "mon/0")
         relation_data = self.harness.get_relation_data(relation_id, "prometheus")
diff --git a/installers/charm/prometheus/tests/test_pod_spec.py b/installers/charm/prometheus/tests/test_pod_spec.py
index 22f6bf5..1adbae6 100644
--- a/installers/charm/prometheus/tests/test_pod_spec.py
+++ b/installers/charm/prometheus/tests/test_pod_spec.py
@@ -286,7 +286,6 @@
         ]
 
         pod_envconfig = pod_spec._make_pod_files(config)
-        print(expected_result, pod_envconfig)
         self.assertListEqual(expected_result, pod_envconfig)
 
     def test_make_readiness_probe(self) -> NoReturn:
diff --git a/installers/charm/prometheus/tox.ini b/installers/charm/prometheus/tox.ini
index 5491c07..1f9442e 100644
--- a/installers/charm/prometheus/tox.ini
+++ b/installers/charm/prometheus/tox.ini
@@ -18,64 +18,98 @@
 # To get in touch with the maintainers, please contact:
 # osm-charmers@lists.launchpad.net
 ##
+#######################################################################################
 
 [tox]
+envlist = flake8, cover, pylint, safety, yamllint
 skipsdist = True
-envlist = unit, lint
-sitepackages = False
-skip_missing_interpreters = False
 
 [testenv]
 basepython = python3.8
 setenv =
+  VIRTUAL_ENV={envdir}
   PYTHONHASHSEED=0
   PYTHONPATH = {toxinidir}/src
-  CHARM_NAME = prometheus
+deps =  -r{toxinidir}/requirements.txt
 
+#######################################################################################
+[testenv:cover]
+deps =  {[testenv]deps}
+        -r{toxinidir}/requirements-test.txt
+commands =
+        sh -c 'rm -f nosetests.xml'
+        coverage erase
+        nose2 -C --coverage src
+        coverage report --omit='*tests*'
+        coverage html -d ./cover --omit='*tests*'
+        coverage xml -o coverage.xml --omit=*tests*
+whitelist_externals = sh
+
+#######################################################################################
+[testenv:safety]
+setenv =
+        LC_ALL=C.UTF-8
+        LANG=C.UTF-8
+deps =  {[testenv]deps}
+        -r{toxinidir}/requirements-test.txt
+commands =
+        - safety check --full-report
+
+#######################################################################################
+[testenv:flake8]
+deps = flake8
+commands =
+        flake8 src/ tests/
+
+#######################################################################################
+[testenv:pylint]
+deps =  {[testenv]deps}
+        -r{toxinidir}/requirements-test.txt
+        pylint
+commands =
+    pylint -E src
+
+#######################################################################################
+[testenv:black]
+deps =  {[testenv]deps}
+        -r{toxinidir}/requirements-test.txt
+        black
+commands =  black --check --diff . --exclude "build/|.tox/|mod/|lib/"
+
+#######################################################################################
+[testenv:yamllint]
+deps =  {[testenv]deps}
+        -r{toxinidir}/requirements-test.txt
+        yamllint
+commands = yamllint .
+
+#######################################################################################
 [testenv:build]
 passenv=HTTP_PROXY HTTPS_PROXY NO_PROXY
+deps =  {[testenv]deps}
+        -r{toxinidir}/requirements-test.txt
+        charmcraft
 whitelist_externals =
   charmcraft
-  rm
-  unzip
+  cp
 commands =
-  rm -rf release prometheus.charm
   charmcraft build
-  unzip prometheus.charm -d release
+  cp -r build 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
-setenv =
-  {[testenv]setenv}
-  PYTHON=coverage run
+#######################################################################################
+[flake8]
+ignore =
+        W291,
+        W293,
+        E123,
+        E125,
+        E226,
+        E241,
+exclude =
+        .git,
+        __pycache__,
+        .tox,
+max-line-length = 120
+show-source = True
+builtins = _
 
-[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/*