Docker build on Alpine fails to run

[neiljp]

See discussion here:
https://chat.zulip.org/#narrow/stream/206-zulip-terminal/topic/docker.20instructions.20fail.20on.20multiple.20machines

ZT appears to build OK in docker, but fails to create (or map?) the zuliprc file required to log in.

This works OK on buster, and worked previously, so one theory I had was it's possible a dependency we added since it last worked on Alpine has a runtime-dependency? It's been an issue at build-time in the past.

@klardotsh suspects a UID/GID mapping issue, though it seems strange that this would work OK on buster.

I mentioned in the discussion about building docker images from commits and testing them automatically, and @klardotsh mentioned some approaches being considered for Zulip, but this is a run-time issue, which we don't currently test for in CI - though maybe we could?

[techsavvyash]

Hey @neiljp can I pick this up?

[neiljp]

@techsavvyash You're welcome to 👍 Please do check the prior discussion, and feel welcome to drop in to the stream on chat.zulip.org.

[neiljp]

I just merged #1310 which upgraded some dependencies, which has the potential to help with this issue, since Alpine is a distro that needs extra files installed in addition to python dependencies.