Run CI in Docker container

[aherrmann]

The buildkite workers are now running on NixOS. However, rules_sh should be tested outside a Nix environment (rules_nixpkgs provides the relevant Nix extensions). We follow rules_haskell's example and run the pipeline in a dedicated Docker container.

[mrkkrp]

The build doesn't seem to get an agent because of monad-bayes. Hopefully later today we'll get free agents.

[aherrmann]

@mrkkrp It got a free agent by now and succeeded.

[mboes]

I'm not sure I understand the requirement that this should be tested on anything that is not NixOS. Is it because we are using a Bazel bindist?

[aherrmann]

I'm not sure I understand the requirement that this should be tested on anything that is not NixOS. Is it because we are using a Bazel bindist?

Yes, because we are using the Bazel bindist and because sh_posix_configure is intended for the non-Nix use-case. So, we want to test it in a non-Nix environment to make sure it works there.

For Nix users rules_nixpkgs provides nixpkgs_sh_posix_configure and rules_nixpkgs contains corresponding tests.