Merge pull request 'add comrade backupbot' (#28) from backupbot into main

Reviewed-on: #28

compose.yml

@@ -74,6 +74,12 @@ services:
       test: ["CMD", "pg_isready", "-U", "synapse"]
     volumes:
       - postgres:/var/lib/postgresql/data
+    deploy:
+      labels:
+          backupbot.backup: "true"
+          backupbot.backup.pre-hook: "mkdir -p /tmp/backup/ && PGPASSWORD=$$(cat $${POSTGRES_PASSWORD_FILE}) pg_dump -U $${POSTGRES_USER} $${POSTGRES_DB} > /tmp/backup/backup.sql"
+          backupbot.backup.post-hook: "rm -rf /tmp/backup"
+          backupbot.backup.path: "/tmp/backup/"
 
 volumes:
   data: