I think that
@stocky-spoon-28903 is asking if we have a container definition for our build environment (e.g what we execute in on Travis). The answer for that is that we do not, since we do not use docker in Travis. We do have
https://github.com/pulumi/scripts/blob/master/ci/install-common-toolchain.sh which is the shell script we run on Travis. You could probably use that as the seed for a developer environment, but we have not done that.
The thing Joe is referring to, I think, was the example we did for CodeShip Pro where they force builds to happen in docker containers. All that work was was putting Pulumi in a container (see:
https://github.com/pulumi/codeship-example/blob/master/Dockerfile). But this did not try to define an environment which could be used to build Pulumi itself.