alpine linux support

[umegaya]

hi, thank you for creating action-tmate! I really love its DX 👍

thie PR will add support for alpine linux, which does not have apt-get.
I added codes to detect linux distro via /etc/os-release and use apk if distro seems to be alpine.

this already runs fine on my github action, like https://github.com/suntomi/deplo/runs/4402074337?check_suite_focus=true#step:7:26

regards,

[dscho]

This looks good, and I am delighted to see support for more Linux distributions!

I have just one request, see below.

[dscho]

The existing code seems to prefer await/async over using Promises via .then(). Let's do the same.

Also, rather than spawning a full-blown shell and two commands to parse a file, it would make more sense to read the file contents and parse via string functions:

const getLinuxDistro = async () => {
  try {
    const osRelease = await fs.promises.readFile("/etc/os-release")
    const match = osRelease.toString().match(/^ID=(.*)$/m)
    return match ? match[1] : "(unknown)"
  } catch (e) {
    return "(unknown)"
  }
}

[umegaya]

@dscho agreed, I have fixed as you suggest. thanks for comment :D

[mxschmitt]

is sudo a thing on alpine?

[umegaya]

@mxschmitt hmm, I think alpine container image (main use case of alpine) does not have it.

I try to fix it, but things bit complex because sudo will be required for invoking apk add sudo if user want to use sudo. so I think 2 options

1. if sudo option is set for alpine, raise error like sudo option is not supported on alpine
2. try invoking apk without optionalSudoPrefix for installing sudo on alpine (but it would not succeed the case user need sudo...)

personally I prefer option 1 because alpine's main use case is as container image, which should not require sudo.

how do you think?

[umegaya]

with c93ade2 I implement option 1.

[umegaya]

I think another option is enable sudo option but don't install sudo command by the action (cancel c93ade2).

some user may use non-root user for their alpine based image.

in this case, user can use the action if they install sudo on their image creation.

[dscho]

An even better method would be to use https://nodejs.org/api/process.html#processgeteuid to determine whether sudo is even needed. I bet that we're running as root in the Alpine container already.

[dscho]

Oh, never mind, I just realized that we're not using sudo by default. Sorry for the noise.