In CI and our development environment we do not rely on the Go environment of the host machine, and instead use Go installed in a container. To simplify things we separate all of Boulder's build dependencies into its own boulder-tools Docker image.

Rather than install multiple versions of Go within the same boulder-tools container we maintain separate images for each Go version we support.

When a new Go version is available we perform several steps to integrate it to our workflow:

1. We add it to the GO_VERSIONS array in tag_and_upload.sh.
2. We run the tag_and_upload.sh script to build, tag, and upload a boulder-tools image for each of the GO_VERSIONS
3. We update .github/workflows/boulder-ci.yml, adding the new docker image tag(s) to the BOULDER_TOOLS_TAG section.

After some time when we have spot checked the new Go release and coordinated a staging/prod environment upgrade with the operations team we can remove the old GO_VERSIONS entries, delete their respective build matrix items, and update docker-compose.yml.