helm-set-image-tag-action

This action is designed to help you automatically update your Helm charts to point to the most recent releases of your application (ie, a Docker Image Tag) and rev your Helm Chart accordingly. The goal is to create a continuous delivery process that is entirely Git based.

Basic Flow

The general idea here is that a human being decides to release a new version of an application from their repository - so a developer creates a Github Release to rev the version of their application (say from v1.2.2 to v1.2.3) after sufficient testing has been done.

Once that has been done, we want to fully automate the process of updating the Helm values.yaml file, as well as revving the Chart.yaml version key, and even updating the Helm Documentation. Here is an example flow.

1. Developer commits code into HEAD in their repository.
2. Testing and iteration occurs on that code...
3. Developer tags new release v1.2.3 pointing to SHA abcdefg1.
4. CI system builds Docker artifact myapp:v1.2.3 (hint: [Nextdoor/docker-image-retag-action][docker-image-retag-action])
5. This action is triggered and runs through a few steps:
   1. Updates the values.yaml file and sets image.tag: v1.2.3
   2. Updates the Chart.yaml and automatically revs the version from 0.1.42 to 0.1.43
   3. Re-generates the Helm Documentation to match
   4. Commits all of the above changes back to a target branch (if commit_branch is set)
   5. Creates a release tag that points to the newly created commit (if commit_tag is set)

Understanding commit_branch

When you set commit_branch, the action starts by checking out the branch you've supplied. This is done so that the newly created commit

Understanding commit_tag

Usage

# .github/workflows/release.yml
name: Release
on:
  push:
    branches:
      # Generally you probably do not want to run this on branches because
      # you'll get a new Helm Chart version commit for every single commit into
      # your branch. It would be very noisy.
      - '!*'
    tags:
      # Trigger this on the tag format that your developers are using for the
      # core application/docker-image tag.
      - v*
jobs:
  release:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@master
      with:
        fetch-depth: '0'  # this is important for the git writeback

    - name: Retag Docker Image for Production
      uses: Nextdoor/docker-image-retag-action@main
        ...

    - name: Update Helm Chart Values
      uses: Nextdoor/helm-set-image-tag-action@main
      with:
        # A comma-separated list of Values files to update. We default to
        # `chart/values.yaml`, but you can patch multiple values files at once if
        # you need to. There should be only one chart being updated though. To
        # update multiple charts, run this action multiple times.
        #
        values_files: charts/app/values.yaml

        # A comma-separated list of keys to update within the Values file(s).
        # The keys should be in Dot-notation and always start with a `.`. Only
        # one "value" can be applied to these tags (see `tag_value` below) - so
        # multiple keys here only makes sense if you use the image tag value in
        # multiple places inside your chart.
        #
        # tag_keys: .image.tag

        # This is the value that will be set in the Values files on the Tag
        # Keys (see above). If this build is running on git tag `v1.2.3` and your
        # docker image tag is `release-v1.2.3`, then you would set this to
        # `release-${{ github.ref }}`
        #
        tag_value: ${{ github.ref }}

        # This is the sem-ver level that will be bumped for each release.
        # `major`, `minor`, `path` or `null` are allowed. If you set `null` then
        # it will skip bumping the version.
        #
        # bump_level: patch

        # `true` or `false` - whether or not to run the helm-docs generator.
        #
        # helm_docs: true

        # Generally you want to set this to whatever your primary `HEAD` commit
        # points to (`main` or `master` typically). Without setting this, a
        # detached-commit will be created but no pointer will exist for it. You
        # will need to introduce your own code to create a branch or tag that
        # points to this commit.
        #
        commit_branch: main

        # Instead of (or in addition to) putting the newly created release
        # commit on the $commit_branch, you can also create a tag that points to
        # this commit. This allows you to avoid writing back to main if you
        # prefer to use git tags to maintain your releases. 
        #
        # In this example, we take the "tag name" that we were triggered on and
        # create a new tag appending "-chart" to it.
        #
        commit_tag: ${{ github.ref }}-chart

        # Override the message used in the git commit.
        #
        # commit_message: Automated commit on behalf-of ${{ github.actor }}

        # Optional commit arguments
        #
        # commit_options: ''

        # Set the action to run in `set -x` mode for very verbose logging. Set
        # to `true` or `false`.
        #
        # verbose: false

        # Optionally run the action in 'dry' mode - where all of the normal
        # actions happen, but no `git commit` happens. Useful for initial testing
        # of the configuration. Set to `true` or `false`.
        #
        # dry: false