[DPE-2717] Copy dashboard changes from K8s and use the correct topolo…

…gy dispatcher (#248)

* Copy dashboard changes from K8s

* Tweak exec command for the topology observer

* Unit test

* Bump libs

lib/charms/data_platform_libs/v0/upgrade.py

@@ -285,7 +285,7 @@ def restart(self, event) -> None:
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 13
+LIBPATCH = 14
 
 PYDEPS = ["pydantic>=1.10,<2", "poetry-core"]
 
@@ -895,6 +895,10 @@ def _on_upgrade_charm(self, event: UpgradeCharmEvent) -> None:
             self.charm.unit.status = WaitingStatus("other units upgrading first...")
             self.peer_relation.data[self.charm.unit].update({"state": "ready"})
 
+            if self.charm.app.planned_units() == 1:
+                # single unit upgrade, emit upgrade_granted event right away
+                getattr(self.on, "upgrade_granted").emit()
+
         else:
             # for k8s run version checks only on highest ordinal unit
             if (

lib/charms/postgresql_k8s/v0/postgresql.py

@@ -19,7 +19,7 @@
 Any charm using this library should import the `psycopg2` or `psycopg2-binary` dependency.
 """
 import logging
-from typing import List, Optional, Set, Tuple
+from typing import Dict, List, Optional, Set, Tuple
 
 import psycopg2
 from psycopg2 import sql
@@ -32,7 +32,7 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 15
+LIBPATCH = 16
 
 INVALID_EXTRA_USER_ROLE_BLOCKING_MESSAGE = "invalid role(s) for extra user roles"
 
@@ -441,7 +441,7 @@ def is_restart_pending(self) -> bool:
     @staticmethod
     def build_postgresql_parameters(
         profile: str, available_memory: int, limit_memory: Optional[int] = None
-    ) -> Optional[dict[str, str]]:
+    ) -> Optional[Dict[str, str]]:
         """Builds the PostgreSQL parameters.
 
         Args:

renovate.json

@@ -41,9 +41,6 @@
       "matchDatasources": ["pypi"],
       "allowedVersions": "<3.0.0",
       "groupName": "Juju 2"
-    }, {
-      "matchPackageNames": ["urllib3"],
-      "allowedVersions": "<2.0.0"
     }, {
       "matchPackageNames": ["pydantic"],
       "allowedVersions": "<2.0.0"

src/charm.py

@@ -101,7 +101,12 @@ def __init__(self, *args):
 
         self.secrets = {APP_SCOPE: {}, UNIT_SCOPE: {}}
 
-        self._observer = ClusterTopologyObserver(self)
+        juju_version = JujuVersion.from_environ()
+        if juju_version.major > 2:
+            run_cmd = "/usr/bin/juju-exec"
+        else:
+            run_cmd = "/usr/bin/juju-run"
+        self._observer = ClusterTopologyObserver(self, run_cmd)
         self.framework.observe(self.on.cluster_topology_change, self._on_cluster_topology_change)
         self.framework.observe(self.on.install, self._on_install)
         self.framework.observe(self.on.leader_elected, self._on_leader_elected)

src/cluster_topology_observer.py

@@ -42,15 +42,17 @@ class ClusterTopologyObserver(Object):
     Observed cluster topology changes cause :class"`ClusterTopologyChangeEvent` to be emitted.
     """
 
-    def __init__(self, charm: CharmBase):
+    def __init__(self, charm: CharmBase, run_cmd: str):
         """Constructor for ClusterTopologyObserver.
 
         Args:
             charm: the charm that is instantiating the library.
+            run_cmd: run command to use to dispatch events.
         """
         super().__init__(charm, "cluster-topology-observer")
 
         self._charm = charm
+        self._run_cmd = run_cmd
 
     def start_observer(self):
         """Start the cluster topology observer running in a new process."""
@@ -79,7 +81,7 @@ def start_observer(self):
                 "src/cluster_topology_observer.py",
                 self._charm._patroni._patroni_url,
                 f"{self._charm._patroni.verify}",
-                "/usr/bin/juju-run",
+                self._run_cmd,
                 self._charm.unit.name,
                 self._charm.charm_dir,
             ],

src/grafana_dashboards/postgresql-metrics.json

@@ -2667,35 +2667,35 @@
       "steppedLine": false,
       "targets": [
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_backend{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_backend_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_backend",
           "refId": "A"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_alloc{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_alloc_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_alloc",
           "refId": "B"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_backend_fsync{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_backend_fsync_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "backend_fsync",
           "refId": "C"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_checkpoint{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_checkpoint_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_checkpoint",
           "refId": "D"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_clean{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_clean_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_clean",
@@ -2973,14 +2973,14 @@
       "steppedLine": false,
       "targets": [
         {
-          "expr": "irate(pg_stat_bgwriter_checkpoint_write_time{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_checkpoint_write_time_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "write_time - Total amount of time that has been spent in the portion of checkpoint processing where files are written to disk.",
           "refId": "B"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_checkpoint_sync_time{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_checkpoint_sync_time_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "sync_time - Total amount of time that has been spent in the portion of checkpoint processing where files are synchronized to disk.",

tests/unit/test_charm.py

@@ -1423,3 +1423,19 @@ def test_get_available_memory(self):
 
         with patch("builtins.open", mock_open(read_data="")):
             self.assertEqual(self.charm.get_available_memory(), 0)
+
+    @patch("charm.ClusterTopologyObserver")
+    @patch("charm.JujuVersion")
+    def test_juju_run_exec_divergence(self, _juju_version: Mock, _topology_observer: Mock):
+        # Juju 2
+        _juju_version.from_environ.return_value.major = 2
+        harness = Harness(PostgresqlOperatorCharm)
+        harness.begin()
+        _topology_observer.assert_called_once_with(harness.charm, "/usr/bin/juju-run")
+        _topology_observer.reset_mock()
+
+        # Juju 3
+        _juju_version.from_environ.return_value.major = 3
+        harness = Harness(PostgresqlOperatorCharm)
+        harness.begin()
+        _topology_observer.assert_called_once_with(harness.charm, "/usr/bin/juju-exec")

tests/unit/test_cluster_topology_observer.py

@@ -41,7 +41,7 @@ class MockCharm(CharmBase):
     def __init__(self, *args):
         super().__init__(*args)
 
-        self.observer = ClusterTopologyObserver(self)
+        self.observer = ClusterTopologyObserver(self, "test-command")
         self.framework.observe(self.on.cluster_topology_change, self._on_cluster_topology_change)
 
     def _on_cluster_topology_change(self, _) -> None: