Add CNPG metrics collection for PostgreSQL dashboard

- Add Tailscale service exposing CNPG metrics on port 9187 (cnpg-metrics.tail8d86e.ts.net)
- Add Prometheus scrape config for cnpg-postgres job
- Update PostgreSQL dashboard to use CNPG metric names (cnpg_* prefix)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ansible/roles/prometheus/templates/prometheus.yml.j2

@@ -13,3 +13,9 @@ scrape_configs:
   - job_name: "loki"
     static_configs:
     - targets: ["localhost:3100"]
+
+  - job_name: "cnpg-postgres"
+    static_configs:
+    - targets: ["cnpg-metrics.tail8d86e.ts.net:9187"]
+      labels:
+        instance: "blumeops-pg"

argocd/manifests/databases/kustomization.yaml

@@ -6,3 +6,4 @@ namespace: databases
 resources:
   - blumeops-pg.yaml
   - service-tailscale.yaml
+  - service-metrics-tailscale.yaml

argocd/manifests/databases/service-metrics-tailscale.yaml

@@ -0,0 +1,22 @@
+# Tailscale LoadBalancer for CNPG metrics access
+# Exposes native postgres_exporter metrics on port 9187
+# Canonical hostname: cnpg-metrics.tail8d86e.ts.net
+apiVersion: v1
+kind: Service
+metadata:
+  name: blumeops-pg-metrics-tailscale
+  namespace: databases
+  annotations:
+    tailscale.com/hostname: "cnpg-metrics"
+    tailscale.com/proxy-class: "default"
+spec:
+  type: LoadBalancer
+  loadBalancerClass: tailscale
+  selector:
+    cnpg.io/cluster: blumeops-pg
+    role: primary
+  ports:
+    - name: metrics
+      port: 9187
+      targetPort: 9187
+      protocol: TCP

argocd/manifests/grafana-config/dashboards/configmap-postgresql.yaml

@@ -54,7 +54,7 @@ data:
           },
           "targets": [
             {
-              "expr": "pg_up",
+              "expr": "cnpg_collector_up",
               "refId": "A"
             }
           ],
@@ -95,7 +95,7 @@ data:
           },
           "targets": [
             {
-              "expr": "pg_stat_activity_count{state=\"active\"}",
+              "expr": "cnpg_backends_total{state=\"active\"}",
               "refId": "A"
             }
           ],
@@ -136,7 +136,7 @@ data:
           },
           "targets": [
             {
-              "expr": "sum(pg_stat_activity_count)",
+              "expr": "sum(cnpg_backends_total)",
               "refId": "A"
             }
           ],
@@ -177,7 +177,7 @@ data:
           },
           "targets": [
             {
-              "expr": "sum(pg_database_size_bytes)",
+              "expr": "sum(cnpg_pg_database_size_bytes)",
               "refId": "A"
             }
           ],
@@ -249,7 +249,7 @@ data:
           },
           "targets": [
             {
-              "expr": "pg_stat_activity_count",
+              "expr": "cnpg_backends_total",
               "legendFormat": "{{state}}",
               "refId": "A"
             }
@@ -322,7 +322,7 @@ data:
           },
           "targets": [
             {
-              "expr": "pg_database_size_bytes{datname!~\"template.*\"}",
+              "expr": "cnpg_pg_database_size_bytes{datname!~\"template.*\"}",
               "legendFormat": "{{datname}}",
               "refId": "A"
             }
@@ -395,22 +395,22 @@ data:
           },
           "targets": [
             {
-              "expr": "rate(pg_stat_database_tup_fetched{datname!~\"template.*\"}[5m])",
+              "expr": "rate(cnpg_pg_stat_database_tup_fetched{datname!~\"template.*\"}[5m])",
               "legendFormat": "{{datname}} fetched",
               "refId": "A"
             },
             {
-              "expr": "rate(pg_stat_database_tup_inserted{datname!~\"template.*\"}[5m])",
+              "expr": "rate(cnpg_pg_stat_database_tup_inserted{datname!~\"template.*\"}[5m])",
               "legendFormat": "{{datname}} inserted",
               "refId": "B"
             },
             {
-              "expr": "rate(pg_stat_database_tup_updated{datname!~\"template.*\"}[5m])",
+              "expr": "rate(cnpg_pg_stat_database_tup_updated{datname!~\"template.*\"}[5m])",
               "legendFormat": "{{datname}} updated",
               "refId": "C"
             },
             {
-              "expr": "rate(pg_stat_database_tup_deleted{datname!~\"template.*\"}[5m])",
+              "expr": "rate(cnpg_pg_stat_database_tup_deleted{datname!~\"template.*\"}[5m])",
               "legendFormat": "{{datname}} deleted",
               "refId": "D"
             }
@@ -483,12 +483,12 @@ data:
           },
           "targets": [
             {
-              "expr": "rate(pg_stat_database_xact_commit{datname!~\"template.*\"}[5m])",
+              "expr": "rate(cnpg_pg_stat_database_xact_commit{datname!~\"template.*\"}[5m])",
               "legendFormat": "{{datname}} commits",
               "refId": "A"
             },
             {
-              "expr": "rate(pg_stat_database_xact_rollback{datname!~\"template.*\"}[5m])",
+              "expr": "rate(cnpg_pg_stat_database_xact_rollback{datname!~\"template.*\"}[5m])",
               "legendFormat": "{{datname}} rollbacks",
               "refId": "B"
             }
@@ -561,7 +561,7 @@ data:
           },
           "targets": [
             {
-              "expr": "pg_database_xid_age_xid_age",
+              "expr": "cnpg_pg_database_xid_age",
               "legendFormat": "{{datname}}",
               "refId": "A"
             }