Unable to start service with nohup due to 'INFO spawnerr: unknown error making dispatchers for 'app_name': EACCES'

Question

I\'m trying to start a service with supervisor, but I get an error saying

INFO spawnerr: unknown error making dispatchers for \'app_name\': EACCES

Answer 1

I get this error when running supervisord in an unprivileged Docker container, when I attempt to have supervisord run as a non-root user, using the [supervisord] [user] directive.

This caused by docker #31243 where the container is started as root then another user is created/switched-to (as per supervisord changing to non-root) and the restrictive permissions on the container's stdin/stdout/stderr via it's TTY.

My workaround is to add the non-root user to the tty group e.g. useradd -G tty supervisord, making-sure that you run with a tty e.g. docker run ... -t or Docker Compose tty: true.