Permissions issue installing gitlab with docker on Mac

Use your user's folder. This will allow you in a sense to bypass the need to setup permissions on an external folder. Worked for me!

    --volume /Users/username/gitlab/config:/etc/gitlab \
    --volume /Users/username/gitlab/logs:/var/log/gitlab \
    --volume /Users/username/gitlab/data:/var/opt/gitlab \

What you need to do is grant Read and Write permissions for everyone on the the host folders that are trying to mount /srv/gitlab/config, /srv/gitlab/logs and /srv/gitlab/data. Right Click > Get Info > Lock Icon.

This problem is related to File system sharing (osxfs) on mac and how it maintains file permissions between the host and the container.