update-go-version.md

How to update Go version

A quick guide to update KubeVirt's Go version.

To update the Go version we need to update the builder image so that it uses the new version, push it to the registry and finally let KubeVirt use the new builder image.

In addition, go rules for bazel have to be updated if the current version does not support the target Go version.

Updating Go Version

Updating builder image

• Change the GIMME_GO version in the hack/builder/Dockerfile to the desired Go version.
• Rebuild the builder image by executing make builder-build.

Publishing builder image

• Publish new builder image with make builder-publish.
  • Note: Proper access rights are required in order to publish builder image.
  • When publish is finished, the builder image tag will be presented. For instance, if the output of make builder-publish is:

    2103210933-9be558add-amd64: digest: sha256:cc83534b5d99da35643f8a2a87830b0dabcb4f130c1db181a835dc8def09174b size: 3271
    + TMP_IMAGES=' quay.io/kubevirt/builder:2103210933-9be558add-amd64'
    + export DOCKER_CLI_EXPERIMENTAL=enabled
    + DOCKER_CLI_EXPERIMENTAL=enabled
    + docker manifest create --amend quay.io/kubevirt/builder:2103210933-9be558add quay.io/kubevirt/builder:2103210933-9be558add-amd64
      Created manifest list quay.io/kubevirt/builder:2103210933-9be558add
    + docker manifest push quay.io/kubevirt/builder:2103210933-9be558add
      sha256:d828eb647e7ef3115f39ff4cb2d5d41da39b4134056e429be16c3a019b521957
    + cleanup
    + rm manifests/ -rf

  • The image tag is 2103210933-9be558add
• Change KUBEVIRT_BUILDER_IMAGE variable in hack/dockerized to the tag from the previous step.
• In WORKSPACE change go_version to the desired Go version.
  • Should look similar to:

    go_register_toolchains(
        go_version = "1.14.14",
        nogo = "@//:nogo_vet",
    )

Update go rules for bazel

• In WORKSPACE find current Bazel release's SHA ID which can be found under io_bazel_rules_go.
  • Should look similar to:

    http_archive(
      name = "io_bazel_rules_go",
      sha256 = "52d0a57ea12139d727883c2fef03597970b89f2cc2a05722c42d1d7d41ec065b",
      urls = [
        ...
      ],
    )

• Visit Bazel's releases page and check whether the current Bazel version supports the new Go version.
  • If it is not supported, replace the io_bazel_rules_go definition with the one provided in Bazel's page.