Add revision to the dashboard title of the Grafana (#510)

With this change, two different OpenSearch applications in different
revisions, will have separate dashboards when related to COS.

- data-platform-helpers was added to use the get_charm_revision
- titles of dashboards are changed during the charm upgrade hook
- config_changed was added on refresh_events of COSAgentProvider to
re-render the dashboards after a charm upgrade

## How to test it

1. Deploy more than one opensearch application
2. Relate both apps with grafana-agent
3. In one of the applications use juju refresh and apply a local build
of this patch
4. Go to the Grafana dashboards an you will see that two dashboards are
created:
  - one with no revision (from charmhub)
  - one with Rev 0 (meaning that is a local build)
  
  
 

![image](https://github.com/user-attachments/assets/d9d82ab6-10b3-4d00-bfa2-f864bbad4d9a)

lib/charms/opensearch/v0/helper_cos.py

@@ -0,0 +1,39 @@
+# Copyright 2025 Canonical Ltd.
+# See LICENSE file for licensing details.
+"""Utility functions for charms COS operations."""
+
+
+import json
+import logging
+from typing import TYPE_CHECKING
+
+from data_platform_helpers.version_check import get_charm_revision
+
+logger = logging.getLogger(__name__)
+
+if TYPE_CHECKING:
+    from charms.opensearch.v0.opensearch_base_charm import OpenSearchBaseCharm
+
+
+def update_grafana_dashboards_title(charm: "OpenSearchBaseCharm") -> None:
+    """Update the title of the Grafana dashboard file to include the charm revision."""
+    revision = get_charm_revision(charm.model.unit)
+    dashboard_path = charm.charm_dir / "src/grafana_dashboards/opensearch.json"
+
+    with open(dashboard_path, "r") as file:
+        dashboard = json.load(file)
+
+    old_title = dashboard.get("title", "Charmed OpenSearch")
+    title_prefix = old_title.split(" - Rev")[0]
+    new_title = f"{old_title} - Rev {revision}"
+    dashboard["title"] = f"{title_prefix} - Rev {revision}"
+
+    logger.info(
+        "Changing the title of dashboard %s from %s to %s",
+        dashboard_path.name,
+        old_title,
+        new_title,
+    )
+
+    with open(dashboard_path, "w") as file:
+        json.dump(dashboard, file, indent=4)

lib/charms/opensearch/v0/opensearch_base_charm.py

@@ -244,6 +244,7 @@ def __init__(self, *args, distro: Type[OpenSearchDistribution] = None):
             metrics_endpoints=[],
             scrape_configs=self._scrape_config,
             refresh_events=[
+                self.on.config_changed,
                 self.on.set_password_action,
                 self.on.secret_changed,
                 self.on[PeerRelationName].relation_changed,

pyproject.toml

@@ -20,6 +20,7 @@ pydantic = "^1.10.17, <2"
 cryptography = "^43.0.0"
 jsonschema = "^4.23.0"
 poetry-core = "^1.9.0"
+data-platform-helpers = "^0.1.4"
 
 
 [tool.poetry.group.charm-libs.dependencies]

src/charm.py

@@ -9,6 +9,7 @@
 
 import ops
 from charms.opensearch.v0.constants_charm import InstallError, InstallProgress
+from charms.opensearch.v0.helper_cos import update_grafana_dashboards_title
 from charms.opensearch.v0.models import PerformanceType
 from charms.opensearch.v0.opensearch_base_charm import OpenSearchBaseCharm
 from charms.opensearch.v0.opensearch_exceptions import OpenSearchInstallError
@@ -137,6 +138,7 @@ def _set_upgrade_status(self):
                 logger.debug(f"Set app status to {self.app.status}")
 
     def _on_upgrade_charm(self, _):
+        update_grafana_dashboards_title(self)
         if not self.performance_profile.current:
             # We are running (1) install or (2) an upgrade on instance that pre-dates profile
             # First, we set this unit's effective profile -> 1G heap and no index templates.

tests/unit/lib/test_helper_cos.py

@@ -0,0 +1,85 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""Unit test for the helper_cos library."""
+
+import json
+import unittest
+from pathlib import Path
+from unittest.mock import MagicMock, PropertyMock, mock_open, patch
+
+from charms.opensearch.v0.helper_cos import update_grafana_dashboards_title
+
+
+class TestCOSGrafanaDashboard(unittest.TestCase):
+
+    @patch("charms.opensearch.v0.helper_cos.get_charm_revision", return_value=167)
+    @patch(
+        "builtins.open",
+        new_callable=mock_open,
+        read_data=json.dumps({"title": "Charmed OpenSearch"}),
+    )
+    @patch("json.dump")
+    def test_update_grafana_dashboards_title_no_prior_revision(
+        self, mock_json_dump, mock_open_func, _
+    ):
+        mock_charm = MagicMock()
+        mock_charm.model.unit = MagicMock()
+        type(mock_charm).charm_dir = PropertyMock(return_value=Path("/fake/charm/dir"))
+
+        update_grafana_dashboards_title(mock_charm)
+
+        expected_updated_dashboard = {"title": "Charmed OpenSearch - Rev 167"}
+        mock_json_dump.assert_called_once_with(
+            expected_updated_dashboard, mock_open_func(), indent=4
+        )
+
+    @patch("charms.opensearch.v0.helper_cos.get_charm_revision", return_value=167)
+    @patch(
+        "builtins.open",
+        new_callable=mock_open,
+        read_data=json.dumps({"title": "Charmed OpenSearch - Rev 166"}),
+    )
+    @patch("json.dump")
+    def test_update_grafana_dashboards_title_prior_revision(
+        self,
+        mock_json_dump,
+        mock_open_func,
+        _,
+    ):
+        mock_charm = MagicMock()
+        mock_charm.model.unit = MagicMock()
+        type(mock_charm).charm_dir = PropertyMock(return_value=Path("/fake/charm/dir"))
+
+        update_grafana_dashboards_title(mock_charm)
+
+        expected_updated_dashboard = {"title": "Charmed OpenSearch - Rev 167"}
+        mock_json_dump.assert_called_once_with(
+            expected_updated_dashboard, mock_open_func(), indent=4
+        )
+
+    @patch("charms.opensearch.v0.helper_cos.get_charm_revision", return_value=167)
+    @patch(
+        "builtins.open",
+        new_callable=mock_open,
+        read_data=json.dumps({"my-content": "content"}),
+    )
+    @patch("json.dump")
+    def test_update_grafana_dashboards_title_json_no_title(
+        self,
+        mock_json_dump,
+        mock_open_func,
+        _,
+    ):
+        mock_charm = MagicMock()
+        mock_charm.model.unit = MagicMock()
+        type(mock_charm).charm_dir = PropertyMock(return_value=Path("/fake/charm/dir"))
+        update_grafana_dashboards_title(mock_charm)
+
+        expected_updated_dashboard = {
+            "title": "Charmed OpenSearch - Rev 167",
+            "my-content": "content",
+        }
+        mock_json_dump.assert_called_once_with(
+            expected_updated_dashboard, mock_open_func(), indent=4
+        )

tests/unit/resources/config/opensearch-security/internal_users.yml

@@ -9,16 +9,16 @@ _meta:
 
 ## Demo users
 
+kibanaserver:
+  hash: $2b$12$VNfTvrDDZ5JjT9.BZDqRTOh6sZoUxdMmgLueB4X0H93E0/e9FinRC
+  reserved: false
+  description: Kibanaserver user
 admin:
-  hash: $2b$12$Cts2k6vk.emW.E1mQN.B5u/5DfwKybaXFRREHfIwUs7RUHNp8h.c.
+  hash: $2b$12$3wL/WsFm7y0S2jyfiyHV4elgGEg2jeXrPFUmYdZGkj5aDF9hpCPFi
   reserved: false
   backend_roles:
   - admin
   opendistro_security_roles:
   - security_rest_api_access
   - all_access
   description: Admin user
-kibanaserver:
-  hash: $2b$12$0ZYW/CiICy1.7YXpRYDjeOLD75qnPAu4I3w5KXZmJvFp1rRiCm8qa
-  reserved: false
-  description: Kibanaserver user