Refactor Umami service in docker-compose: add umami-db service and configure database connection

docker-compose.yml

@@ -118,7 +118,10 @@ services:
     image: umamisoftware/umami:postgresql-latest
     container_name: umami
     restart: unless-stopped
+    depends_on:
+      - umami-db
     environment:
+      DATABASE_URL: postgresql://umami:${UMAMI_DB_PASS}@umami-db:5432/umami
       APP_SECRET: ${UMAMI_APP_SECRET}
       TRACKER_SCRIPT_NAME: umami
       TZ: "${TZ}"
@@ -131,6 +134,19 @@ services:
       - traefik.http.routers.umami.middlewares=security-headers
       - traefik.http.services.umami.loadbalancer.server.port=3000
 
+  umami-db:
+    image: postgres:15-alpine
+    container_name: umami-db
+    restart: unless-stopped
+    environment:
+      POSTGRES_DB: umami
+      POSTGRES_USER: umami
+      POSTGRES_PASSWORD: ${UMAMI_DB_PASS}
+      TZ: "${TZ}"
+    networks: [internal]
+    volumes:
+      - umami_db_data:/var/lib/postgresql/data
+
   ## ─────────────────────────────────────────────
   ## Uptime Kuma — status page / checks
   ## ─────────────────────────────────────────────