Permissions of DockerEnvironment.SharedDir()

[esnible]

I had several hours of confusion and difficulty because on my test machine the Docker instances received a /shared directory (holding /shared/config etc) with permissions rwxr-xr-x but on a CircleCI machine running a PR the Docker instances saw permissions rwx------ for /shared.

(This affects test containers that don't run as root.)

It is unclear to me if the problem is that only I am using Docker on a Mac, I am using Go 1.17, or I have a different umask than the CircleCI machine. I tried setting my umask to 000 but was unable to get my builds to fail the same way as the CircleCI builds.

[bwplotka]

I think I experienced this in the past too. This is a common problem if someone puts NOBODY in the container. Somehow setting UserID in your container when scheduling it via e2e to 1000 works 🙈

But your case might be different indeed, just a mismatch of perms/users on Linux vs Mac?

Anyway, worth def to investigate - we need to find better way I guess or document this (:

[bwplotka]

Common pattern is to use User: strconv.Itoa(os.Getuid()), but again, it might be different for Mac setups.