Adding HA support for Grafana charm

Change-Id: Icac0e15706e49cb387ac6686cb26337b98a5a319
Signed-off-by: David Garcia <david.garcia@canonical.com>

installers/charm/grafana/config.yaml

@@ -63,3 +63,22 @@ options:
       ImagePullPolicy configuration for the pod.
       Possible values: always, ifnotpresent, never
     default: always
+  mysql_uri:
+    type: string
+    description: |
+      Mysql uri with the following format:
+        mysql://<user>:<pass>@<host>:<port>/<database>
+  admin_user:
+    type: string
+    description: Admin user
+    default: admin
+  log_level:
+    type: string
+    description: |
+      Logging level for Grafana. Options are “debug”, “info”,
+      “warn”, “error”, and “critical”.
+    default: info
+  port:
+    description: The port grafana-k8s will be listening on
+    type: int
+    default: 3000

installers/charm/grafana/metadata.yaml

@@ -41,3 +41,9 @@ resources:
 requires:
   prometheus:
     interface: prometheus
+  db:
+    interface: mysql
+    limit: 1
+peers:
+  cluster:
+    interface: grafana-cluster

installers/charm/grafana/src/charm.py

@@ -25,12 +25,15 @@
 from ipaddress import ip_network
 import logging
 from pathlib import Path
+import secrets
 from string import Template
 from typing import NoReturn, Optional
 from urllib.parse import urlparse
 
 from ops.main import main
 from opslib.osm.charm import CharmedOsmBase, RelationsMissing
+from opslib.osm.interfaces.grafana import GrafanaCluster
+from opslib.osm.interfaces.mysql import MysqlClient
 from opslib.osm.interfaces.prometheus import PrometheusClient
 from opslib.osm.pod import (
     ContainerV3Builder,
@@ -43,10 +46,11 @@ from opslib.osm.validator import ModelValidator, validator
 
 logger = logging.getLogger(__name__)
 
-PORT = 3000
-
 
 class ConfigModel(ModelValidator):
+    log_level: str
+    port: int
+    admin_user: str
     max_file_size: int
     osm_dashboards: bool
     site_url: Optional[str]
@@ -56,6 +60,16 @@ class ConfigModel(ModelValidator):
     tls_secret_name: Optional[str]
     image_pull_policy: Optional[str]
 
+    @validator("log_level")
+    def validate_log_level(cls, v):
+        allowed_values = ("debug", "info", "warn", "error", "critical")
+        if v not in allowed_values:
+            separator = '", "'
+            raise ValueError(
+                f'incorrect value. Allowed values are "{separator.join(allowed_values)}"'
+            )
+        return v
+
     @validator("max_file_size")
     def validate_max_file_size(cls, v):
         if v < 0:
@@ -94,15 +108,20 @@ class GrafanaCharm(CharmedOsmBase):
 
     def __init__(self, *args) -> NoReturn:
         """Prometheus Charm constructor."""
-        super().__init__(*args, oci_image="image")
-
+        super().__init__(*args, oci_image="image", mysql_uri=True)
+        # Initialize relation objects
         self.prometheus_client = PrometheusClient(self, "prometheus")
-        self.framework.observe(
-            self.on["prometheus"].relation_changed, self.configure_pod
-        )
-        self.framework.observe(
-            self.on["prometheus"].relation_broken, self.configure_pod
-        )
+        self.grafana_cluster = GrafanaCluster(self, "cluster")
+        self.mysql_client = MysqlClient(self, "db")
+        # Observe events
+        event_observer_mapping = {
+            self.on["prometheus"].relation_changed: self.configure_pod,
+            self.on["prometheus"].relation_broken: self.configure_pod,
+            self.on["db"].relation_changed: self.configure_pod,
+            self.on["db"].relation_broken: self.configure_pod,
+        }
+        for event, observer in event_observer_mapping.items():
+            self.framework.observe(event, observer)
 
     def _build_dashboard_files(self, config: ConfigModel):
         files_builder = FilesV3Builder()
@@ -133,30 +152,46 @@ class GrafanaCharm(CharmedOsmBase):
         )
         return files_builder.build()
 
-    def _check_missing_dependencies(self):
+    def _check_missing_dependencies(self, config: ConfigModel, external_db: bool):
         missing_relations = []
 
         if self.prometheus_client.is_missing_data_in_app():
             missing_relations.append("prometheus")
 
+        if not external_db and self.mysql_client.is_missing_data_in_unit():
+            missing_relations.append("db")
+
         if missing_relations:
             raise RelationsMissing(missing_relations)
 
-    def build_pod_spec(self, image_info):
+    def build_pod_spec(self, image_info, **kwargs):
         # Validate config
         config = ConfigModel(**dict(self.config))
+        mysql_config = kwargs["mysql_config"]
+        if mysql_config.mysql_uri and not self.mysql_client.is_missing_data_in_unit():
+            raise Exception("Mysql data cannot be provided via config and relation")
+
         # Check relations
-        self._check_missing_dependencies()
+        external_db = True if mysql_config.mysql_uri else False
+        self._check_missing_dependencies(config, external_db)
+
+        # Get initial password
+        admin_initial_password = self.grafana_cluster.admin_initial_password
+        if not admin_initial_password:
+            admin_initial_password = _generate_random_password()
+            self.grafana_cluster.set_initial_password(admin_initial_password)
+
         # Create Builder for the PodSpec
         pod_spec_builder = PodSpecV3Builder()
+
         # Build Container
         container_builder = ContainerV3Builder(
             self.app.name, image_info, config.image_pull_policy
         )
-        container_builder.add_port(name=self.app.name, port=PORT)
+        container_builder.add_port(name=self.app.name, port=config.port)
         container_builder.add_http_readiness_probe(
             "/api/health",
-            PORT,
+            config.port,
             initial_delay_seconds=10,
             period_seconds=10,
             timeout_seconds=5,
@@ -164,7 +199,7 @@ class GrafanaCharm(CharmedOsmBase):
         )
         container_builder.add_http_liveness_probe(
             "/api/health",
-            PORT,
+            config.port,
             initial_delay_seconds=60,
             timeout_seconds=30,
             failure_threshold=10,
@@ -179,9 +214,30 @@ class GrafanaCharm(CharmedOsmBase):
             "/etc/grafana/provisioning/datasources/",
             self._build_datasources_files(),
         )
+
+        container_builder.add_envs(
+            {
+                "GF_SERVER_HTTP_PORT": config.port,
+                "GF_LOG_LEVEL": config.log_level,
+                "GF_SECURITY_ADMIN_USER": config.admin_user,
+                "GF_SECURITY_ADMIN_PASSWORD": {
+                    "secret": {"name": "grafana-admin-secret", "key": "admin-password"}
+                },
+                "GF_DATABASE_URL": {
+                    "secret": {"name": "grafana-admin-secret", "key": "mysql-url"}
+                },
+            },
+        )
         container = container_builder.build()
         # Add container to pod spec
         pod_spec_builder.add_container(container)
+        pod_spec_builder.add_secret(
+            "grafana-admin-secret",
+            {
+                "admin-password": admin_initial_password,
+                "mysql-url": mysql_config.mysql_uri or self.mysql_client.get_uri(),
+            },
+        )
         # Add ingress resources to pod spec if site url exists
         if config.site_url:
             parsed = urlparse(config.site_url)
@@ -213,11 +269,17 @@ class GrafanaCharm(CharmedOsmBase):
             else:
                 annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 
-            ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
+            ingress_resource_builder.add_rule(
+                parsed.hostname, self.app.name, config.port
+            )
             ingress_resource = ingress_resource_builder.build()
             pod_spec_builder.add_ingress_resource(ingress_resource)
         return pod_spec_builder.build()
 
 
+def _generate_random_password():
+    return secrets.token_hex(16)
+
+
 if __name__ == "__main__":
     main(GrafanaCharm)

installers/charm/grafana/tests/test_charm.py

@@ -23,6 +23,7 @@
 import sys
 from typing import NoReturn
 import unittest
+from unittest.mock import patch
 
 from charm import GrafanaCharm
 from ops.model import ActiveStatus, BlockedStatus
@@ -69,10 +70,49 @@ class TestCharm(unittest.TestCase):
         # Assertions
         self.assertIsInstance(self.harness.charm.unit.status, ActiveStatus)
 
+    @patch("opslib.osm.interfaces.grafana.GrafanaCluster.set_initial_password")
+    def test_with_db_relation_and_prometheus(self, _) -> NoReturn:
+        self.initialize_prometheus_relation()
+        self.initialize_mysql_relation()
+        self.assertIsInstance(self.harness.charm.unit.status, ActiveStatus)
+
+    @patch("opslib.osm.interfaces.grafana.GrafanaCluster.set_initial_password")
+    def test_with_db_config_and_prometheus(self, _) -> NoReturn:
+        self.initialize_prometheus_relation()
+        self.initialize_mysql_config()
+        self.assertIsInstance(self.harness.charm.unit.status, ActiveStatus)
+
     def test_with_prometheus(
         self,
     ) -> NoReturn:
         """Test to see if prometheus relation is updated."""
+        self.initialize_prometheus_relation()
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+    def test_with_db_config(self) -> NoReturn:
+        "Test with mysql config"
+        self.initialize_mysql_config()
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+    @patch("opslib.osm.interfaces.grafana.GrafanaCluster.set_initial_password")
+    def test_with_db_relations(self, _) -> NoReturn:
+        "Test with relations"
+        self.initialize_mysql_relation()
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+    def test_exception_db_relation_and_config(
+        self,
+    ) -> NoReturn:
+        "Test with relations and config. Must throw exception"
+        self.initialize_mysql_config()
+        self.initialize_mysql_relation()
+        # Verifying status
+        self.assertIsInstance(self.harness.charm.unit.status, BlockedStatus)
+
+    def initialize_prometheus_relation(self):
         relation_id = self.harness.add_relation("prometheus", "prometheus")
         self.harness.add_relation_unit(relation_id, "prometheus/0")
         self.harness.update_relation_data(
@@ -81,8 +121,25 @@ class TestCharm(unittest.TestCase):
             {"hostname": "prometheus", "port": 9090},
         )
 
-        # Verifying status
-        self.assertNotIsInstance(self.harness.charm.unit.status, BlockedStatus)
+    def initialize_mysql_config(self):
+        self.harness.update_config(
+            {"mysql_uri": "mysql://grafana:$grafanapw$@host:3606/db"}
+        )
+
+    def initialize_mysql_relation(self):
+        relation_id = self.harness.add_relation("db", "mysql")
+        self.harness.add_relation_unit(relation_id, "mysql/0")
+        self.harness.update_relation_data(
+            relation_id,
+            "mysql/0",
+            {
+                "host": "mysql",
+                "port": 3306,
+                "user": "mano",
+                "password": "manopw",
+                "root_password": "rootmanopw",
+            },
+        )
 
 
 if __name__ == "__main__":