This directory includes scripts to build the docker container image used for building flutter/flutter in our CI system (currently [Cirrus](cirrus-ci.org)). To run the scripts, you have to set up `docker` and `gcloud`. Please refer to the [internal flutter team doc](go/flutter-team) for how to set up in a Google internal environment. To debug the image locally: * (Optional) edit the `Dockerfile` to change how the container image is built. * Run `./docker_build.sh` to build the container image (`sudo` permission is required) * Run `./docker_attach.sh` to start a container from the image and attach to its internal bash shell. From here, you can invoke shell commands from the `.cirrus.yml` (you will have to manually run any `setup` steps; e.g. the container will not have the Flutter repo cloned yet).