add backup config

compose.yml

@@ -53,6 +53,14 @@ services:
       retries: 6
     volumes:
       - "postgres_data:/var/lib/postgresql/data"
+    deploy:
+      labels:
+        backupbot.backup: "true"
+        backupbot.backup.pre-hook: sh -c 'pg_dump -U "$$POSTGRES_USER" -Fc "$$POSTGRES_DB" | gzip > "/postgres.dump.gz"'
+        backupbot.backup.path: "/postgres.dump.gz"
+        backupbot.backup.post-hook: "rm -f /postgres.dump.gz"
+        backupbot.restore: "true"
+        backupbot.restore.post-hook: sh -c 'gzip -d /postgres.dump.gz && pg_restore --clean -U "$$POSTGRES_USER" --dbname="$$POSTGRES_DB" < /postgres.dump && rm -f /postgres.dump'
 
 secrets:
   db_password: