[Example] Add grafana+prometheus example

README.md

@@ -584,7 +584,12 @@ Cutover can be done atomically with multiple PgDog containers because `RELOAD` d
 📘 **[Metrics](https://docs.pgdog.dev/features/metrics/)**
 
 PgDog exposes both the standard PgBouncer-style admin database, an OpenMetrics endpoint and can push metrics to an OTEL endpoint. The admin database isn't 100% compatible,
-so we recommend you use either OpenMetrics or OTEL ingestion for monitoring. Example Datadog configuration and dashboard are [included](examples/datadog).
+so we recommend you use either OpenMetrics or OTEL ingestion for monitoring.
+
+We include two examples:
+
+- [Datadog configuration and dashboard](examples/datadog)
+- [Graphana + Prometheus configuration and dashboard](examples/grafana_prometheus)
 
 
 ## Running PgDog locally

examples/grafana_prometheus/README.md

@@ -0,0 +1,32 @@
+# Grafana + Prometheus
+
+Pushes PgDog metrics to Prometheus over OTLP and visualizes them in Grafana.
+
+```
+pgdog  --OTLP push (every 5s)-->  prometheus  <--  grafana
+```
+
+## Push, not scrape
+
+PgDog's OTEL exporter (`[otel]` block in `pgdog.toml`) POSTs OTLP JSON to
+Prometheus's built-in OTLP receiver, enabled with `--web.enable-otlp-receiver`
+(see `docker-compose.metrics.yml`). `prometheus.yml` has no scrape jobs —
+Prometheus only ingests what PgDog pushes.
+
+Metric names are prefixed with `pgdog_` (via `namespace` in `[otel]`); OTLP
+attributes become Prometheus labels.
+
+## Grafana provisioning
+
+`provisioning/grafana/` is mounted into `/etc/grafana/provisioning/`, so the
+Prometheus datasource and the PgDog dashboard show up automatically on first
+boot.
+
+## Running
+
+```sh
+docker compose up
+```
+
+- Prometheus — http://127.0.0.1:9090
+- Grafana — http://127.0.0.1:3000 (admin / admin), _PgDog_ folder

examples/grafana_prometheus/docker-compose.metrics.yml

@@ -0,0 +1,31 @@
+services:
+  prometheus:
+    image: prom/prometheus:latest
+    command:
+      - --config.file=/etc/prometheus/prometheus.yml
+      - --web.enable-otlp-receiver
+    volumes:
+      - ./provisioning/prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
+      - prometheus_data:/prometheus
+    ports:
+      - 9090:9090
+
+  grafana:
+    image: grafana/grafana:latest
+    depends_on:
+      - prometheus
+    environment:
+      GF_SECURITY_ADMIN_USER: admin
+      GF_SECURITY_ADMIN_PASSWORD: admin
+      GF_AUTH_ANONYMOUS_ENABLED: "true"
+      GF_AUTH_ANONYMOUS_ORG_ROLE: Viewer
+    volumes:
+      - ./provisioning/grafana/datasources:/etc/grafana/provisioning/datasources
+      - ./provisioning/grafana/dashboards:/etc/grafana/provisioning/dashboards
+      - grafana_data:/var/lib/grafana
+    ports:
+      - 3000:3000
+
+volumes:
+  prometheus_data:
+  grafana_data:

examples/grafana_prometheus/docker-compose.yml

@@ -0,0 +1,45 @@
+include:
+  - ./docker-compose.metrics.yml
+
+services:
+  db0:
+    image: postgres:17
+    environment:
+      POSTGRES_PASSWORD: postgres
+    ports:
+      - 6000:5432
+    volumes:
+      - shard_0:/var/lib/postgresql/data
+  db1:
+    image: postgres:17
+    environment:
+      POSTGRES_PASSWORD: postgres
+    ports:
+      - 6001:5432
+    volumes:
+      - shard_1:/var/lib/postgresql/data
+  db2:
+    image: postgres:17
+    environment:
+      POSTGRES_PASSWORD: postgres
+    ports:
+      - 6002:5432
+    volumes:
+      - shard_2:/var/lib/postgresql/data
+
+  pgdog:
+    image: ghcr.io/pgdogdev/pgdog:main
+    depends_on:
+      - db0
+      - db1
+      - db2
+    volumes:
+      - ./pgdog.toml:/pgdog/pgdog.toml
+      - ./users.toml:/pgdog/users.toml
+    ports:
+      - 6432:6432
+
+volumes:
+  shard_0:
+  shard_1:
+  shard_2:

examples/grafana_prometheus/pgdog.toml

@@ -0,0 +1,29 @@
+#
+# PgDog configuration.
+#
+
+[general]
+host = "0.0.0.0"
+
+[otel]
+endpoint = "http://prometheus:9090/api/v1/otlp/v1/metrics"
+namespace = "pgdog_"
+push_interval = 5000
+
+[[databases]]
+name = "postgres"
+host = "db0"
+port = 5432
+shard = 0
+
+[[databases]]
+name = "postgres"
+host = "db1"
+port = 5432
+shard = 1
+
+[[databases]]
+name = "postgres"
+host = "db2"
+port = 5432
+shard = 2

examples/grafana_prometheus/provisioning/grafana/dashboards/dashboards.yml

@@ -0,0 +1,12 @@
+apiVersion: 1
+
+providers:
+  - name: PgDog
+    orgId: 1
+    folder: PgDog
+    type: file
+    disableDeletion: false
+    editable: true
+    updateIntervalSeconds: 30
+    options:
+      path: /etc/grafana/provisioning/dashboards