This action packages your action as an OCI container and publishes it to the GitHub Container registry. This allows your action to be consumed as an immutable package if a SemVer is specified in the consumer's workflow file.

Your workflow can be triggered by any event which has a GITHUB_REF that points to a Git tag. Some examples of these events are:

• release (uses tag associated with release)
• push (only applies to pushed tags)
• workflow_dispatch (only applies if subject of dispatch is a tag)

The associated tag must follow semantic versioning - this tag value will be used to create a package version.

Consumers of your action will then be able to specify that version to consume your action from the package, e.g.

• - uses: your-name/your-action@v1.2.3
• - uses: your-name/your-action@v1

Such packages will come with stronger security guarantees for consumers than existing git-based action resolution, such as:

• Provenance attestations generated using the @actions/attest package
• Tag immutability - it will not be possible to overwrite tags once published, ensuring versions of an action can't change once in use
• Namespace immutability - it will not be possible to delete and recreate the package with different content; this would undermine tag immutability

An actions workflow file like the following should be placed in your action repository:

name: "Publish Immutable Action Version"
on:
  release:
    types: [published]
jobs:
  publish:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      id-token: write
      packages: write
    steps:
    - name: Check out repo
      uses: actions/checkout@v4
    - name: Publish
      id: publish
      uses: actions/publish-immutable-action@0.0.3

The scripts and documentation in this project are released under the MIT License.