Add optional Postgres backup service

docker-compose.yml

@@ -216,6 +216,22 @@ services:
       interval: 5s
       timeout: 3s
       retries: 10
+  db-backup:
+    build:
+      context: ./docker/pg_backup
+    environment:
+      POSTGRES_HOST: db
+      POSTGRES_USER: ${POSTGRES_USER}
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+      POSTGRES_DB: ${POSTGRES_DB}
+      BACKUP_RETENTION_DAYS: ${BACKUP_RETENTION_DAYS:-7}
+    volumes:
+      - ./backups/postgres:/backups
+    depends_on:
+      db:
+        condition: service_healthy
+    restart: on-failure
+    profiles: ["db-backup"]
 volumes:
   postgres_data:
   monerod_data: