This directory includes scripts to build the docker container image used forbuilding flutter/flutter in our CI system (currently [Cirrus](cirrus-ci.org)).In order to run the scripts, you have to setup `docker` and `gcloud`. Pleaserefer to the [internal flutter team doc](go/flutter-team) for how to setup in aGoogle internal environment.After setup,* edit `Dockerfile` to change how the container image is built.* run `./build_docker.sh` to build the container image.* run `./push_docker.sh` to push the image to google cloud registry. This will affect our CI tests.