backup database

The Postgres database can be backed up with the following command:

docker compose -f /opt/simplelogin/docker-compose.yaml \
  exec postgres pg_dump -U user -F c -b -v -f /tmp/simplelogin.sql simplelogin

• -F c is _custom format (compressed and able to do in parallel with -j N)
• -b is _including blobs`
• -v is _verbose`
• -fis the backup file name