Document how to use Briefcase in CI

[freakboy3742]

We should add a topic guide for how to incorporate Briefcase into a CI setup.

This includes:

• On a pull request, running:
  • code style checks
  • checking for errors in documentation
  • running the test suite
  • checking for release notes
• Tagging a new app release.
• Signing a released app.
• Publishing a new release.

This will, by necessity, be a very opinionated guide; I would currently expect it to reccomend:

• Github Actions for CI configuration
• towncrier for release notes
• flake8 (possibly mentioning black)
• sphinx for docs
• tox as a common point of testing configuration
• pytest to run test suites

Traveltips currently has an incomplete CI configuration, but can serve as a good "working example". Briefcase has a much more complete CI configuration.

[saroad2]

As you probably remember, I incorporate Briefcase in my CI/CD process of Eddington for about a few months now, but I'm using CircleCI as my platform for that.

If anyone who works on this issue needs some reference, he/she can take a look here to see how I did it there.

[jgirardet]

is briefcase create runnable now on github action ?
There are problems with docker.
For now it fails on linux.

• Github action doesn't provide ubuntu 16.04 so you can't use --no-docker (I'm not sure about it)
• Github runner 18.04 provide an outdated version of docker (see Docker version on azure/github actions #429)
• Github runner 20.04 fails for the following reason : the input device is not a TTY (https://pipelines.actions.githubusercontent.com/ppe4ZSLak9UTOCP3VTfZBea8jfANvOikJ7KH4UBWg38usmFQSU/_apis/pipelines/1/runs/477/signedlogcontent/4?urlExpires=2020-06-28T17%3A52%3A59.8504242Z&urlSigningMethod=HMACV1&urlSignature=YKVqhxtQ6%2BOi7iPmhgJF%2FYM8sSlepBu04mpPz%2B4BcWM%3D)
  maybe a fix there (https://serverfault.com/questions/897847/what-does-the-input-device-is-not-a-tty-exactly-mean-in-docker-run-output). I have no knowledge on docker, I can't help on it, just report.

[freakboy3742]

@jgirardet Not sure where you got the idea that Github Actions doesn't have an Ubuntu 16.04 environment - it's definitely on their official list

As for the "input device is not a TTY" error - I'm not sure what specifically caused that (and the log has expired); but that will almost certainly be because the console is asking for input. There's a --no-input flag to explicitly turn that off (and fall back to safe defaults).

[jgirardet]

@freakboy3742 ok sorry it's fine on 16.04 (how I missed it ?) but it's not working on ubuntu 20.04 even with `--no-input`` : https://pastebin.com/FyvENBip
"input device is not a TTY" is 5 lines before the end of the log.

Concerning this I could "maybe" reproduce it locally. With pycharm you can run some commands outside a terminal (its called run configurations). If I create a configuration which runs python -m briefcase create --no-input. I have the same error.
Commenting the line 174 "--tty" of docker.py file seems to fix the error. I don't know what does --tty so I have no idea if it's a usable fix.

[freakboy3742]

@jgirardet Interesting - it makes sense that would be failing; --tty is attempting to allocate a pseudo terminal to the docker container. The downside to removing --tty is that you won't see the output of the Docker container as it builds, which can be useful debugging detail.

Do you still see a failure if you comment out the --interactive instead? That flag attempts to connect stdin, which is the underlying problem (CI doesn't have an stdin); I wonder if enabling the tty, but disabling interactive would allow us to have the best of both worlds (visible logs, but able to work under CI)

[freakboy3742]

This workflow contains details for how to sign a Windows binary in CI. The example code is slightly old, as it installs a code-signing-windows branch of Briefcase from github; that is no longer required, as that branch has been fully merged into the stable Briefcase release.