name: "Attest Build Provenance"
description: "Generate provenance attestations for build artifacts"
author: "GitHub"
branding:
  color: "blue"
  icon: "lock"

inputs:
  subject-path:
    description: >
      Path to the artifact serving as the subject of the attestation. Must
      specify exactly one of "subject-path", "subject-digest", or
      "subject-checksums". May contain a glob pattern or list of paths (total
      subject count cannot exceed 1024).
    required: false
  subject-digest:
    description: >
      Digest of the subject for which provenance will be generated. Must be in
      the form "algorithm:hex_digest" (e.g. "sha256:abc123..."). Must specify
      exactly one of "subject-path", "subject-digest", or "subject-checksums".
    required: false
  subject-name:
    description: >
      Subject name as it should appear in the attestation. Required when
      identifying the subject with the "subject-digest" input.
  subject-checksums:
    description: >
      Path to checksums file containing digest and name of subjects for
      attestation. Must specify exactly one of "subject-path", "subject-digest",
      or "subject-checksums".
    required: false
  predicate-type:
    description: >
      URI identifying the type of the predicate. Required when using "predicate"
      or "predicate-path" for custom attestations.
    required: false
  predicate:
    description: >
      String containing the value for the attestation predicate. String length
      cannot exceed 16MB. Must supply exactly one of "predicate-path" or
      "predicate" when creating custom attestations.
    required: false
  predicate-path:
    description: >
      Path to the file which contains the content for the attestation predicate.
      File size cannot exceed 16MB. Must supply exactly one of "predicate-path"
      or "predicate" when creating custom attestations.
    required: false
  push-to-registry:
    description: >
      Whether to push the provenance statement to the image registry. Requires
      that the "subject-name" parameter specify the fully-qualified image name
      and that the "subject-digest" parameter be specified. Defaults to false.
    default: false
    required: false
  create-storage-record:
    description: >
      Whether to create a storage record for the artifact. Requires that
      push-to-registry is set to true. Defaults to true.
    default: true
    required: false
  show-summary:
    description: >
      Whether to attach a list of generated attestations to the workflow run
      summary page. Defaults to true.
    default: true
    required: false
  github-token:
    description: >
      The GitHub token used to make authenticated API requests.
    default: ${{ github.token }}
    required: false

outputs:
  bundle-path:
    description: "The path to the file containing the attestation bundle."
    value: ${{ steps.attest.outputs.bundle-path }}
  attestation-id:
    description: "The ID of the attestation."
    value: ${{ steps.attest.outputs.attestation-id }}
  attestation-url:
    description: "The URL for the attestation summary."
    value: ${{ steps.attest.outputs.attestation-url }}
  storage-record-ids:
    description: "GitHub IDs for the storage records"
    value: ${{ steps.attest.outputs.storage-record-ids }}

runs:
  using: "composite"
  steps:
    - name: Attest
      id: attest
      env:
        NODE_OPTIONS: "--max-http-header-size=32768"
      uses: actions/attest@c32b4b8b198b65d0bd9d63490e847ff7b53989d4 # v4.0.0
      with:
        subject-path: ${{ inputs.subject-path }}
        subject-name: ${{ inputs.subject-name }}
        subject-digest: ${{ inputs.subject-digest }}
        subject-checksums: ${{ inputs.subject-checksums }}
        predicate-type: ${{ inputs.predicate-type }}
        predicate: ${{ inputs.predicate }}
        predicate-path: ${{ inputs.predicate-path }}
        push-to-registry: ${{ inputs.push-to-registry }}
        create-storage-record: ${{ inputs.create-storage-record }}
        show-summary: ${{ inputs.show-summary }}
        github-token: ${{ inputs.github-token }}