File permission issue with synapse/data directory when starting containers

[ashfame]

When starting up the containers via docker compose, Synapse failed to start and the error reported was

PermissionError: [Errno 13] Permission denied: '/synapse/data/media_store'

Only when I bumped up the permission to 777 (I tried 775 before 777) for the synapse/data directory, I was able to get synapse up and running.