Update gh-at-container.yml

.github/workflows/gh-at-container.yml

@@ -1,46 +1,45 @@
-name: GHAT - Signed - Container
-
+name: GHAT - Container
 # This workflow uses actions that are not certified by GitHub.
 # They are provided by a third-party and are governed by
 # separate terms of service, privacy policy, and support
 # documentation.
-
 on:
   workflow_dispatch:
-  # schedule:
-  #   - cron: '15 12 * * *'
-  # push:
-  #   branches: [ "main" ]
+  schedule:
+    - cron: '15 12 * * *'
+  push:
+    branches: ["main"]
     # Publish semver tags as releases.
-  #   tags: [ 'v*.*.*' ]
-  # pull_request:
-  #   branches: [ "main" ]
-
+    tags: ['v*.*.*']
+  pull_request:
+    branches: ["main"]
 env:
   # Use docker.io for Docker Hub if empty
   REGISTRY: ghcr.io
   # github.repository as <account>/<repo>
   IMAGE_NAME: ${{ github.repository }}
-
 jobs:
   build:
-
     runs-on: ubuntu-latest
     permissions:
-      contents: write
+      contents: read
       packages: write
       # This is used to complete the identity challenge
       # with sigstore/fulcio when running outside of PRs.
       id-token: write
-
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
-
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3
+      # Install the cosign tool except on PR
+      # https://github.com/sigstore/cosign-installer
+      - name: Install cosign
+        if: github.event_name != 'pull_request'
+        uses: sigstore/cosign-installer@6e04d228eb30da1757ee4e1dd75a0ec73a653e06 #v3.1.1
+        with:
+          cosign-release: 'v2.1.1'
       # Workaround: https://github.com/docker/build-push-action/issues/461
       - name: Setup Docker buildx
         uses: docker/setup-buildx-action@79abd3f86f79a9d68a23c75a09a9a85889262adf
-
       # Login against a Docker registry except on PR
       # https://github.com/docker/login-action
       - name: Log into registry ${{ env.REGISTRY }}
@@ -50,15 +49,13 @@ jobs:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
-
       # Extract metadata (tags, labels) for Docker
       # https://github.com/docker/metadata-action
       - name: Extract Docker metadata
         id: meta
         uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
-
       # Build and push Docker image with Buildx (don't push on PR)
       # https://github.com/docker/build-push-action
       - name: Build and push Docker image
@@ -67,14 +64,28 @@ jobs:
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}
-          tags: ghcr.io/rdimitrov/a-testrepo:ghatsigned
+          tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
-          platforms: linux/amd64,linux/arm64
       - name: generate build provenance
+        if: ${{ github.event_name != 'pull_request' }}
         uses: github-early-access/generate-build-provenance@main
         with:
-          subject-name: ghcr.io/rdimitrov/a-testrepo:ghatsigned
+          subject-name: ${{ steps.meta.outputs.tags }}
           subject-digest: ${{ steps.build-and-push.outputs.digest }}
           push-to-registry: false
+      # Sign the resulting Docker image digest except on PRs.
+      # This will only write to the public Rekor transparency log when the Docker
+      # repository is public to avoid leaking data.  If you would like to publish
+      # transparency data even for private images, pass --force to cosign below.
+      # https://github.com/sigstore/cosign
+      - name: Sign the published Docker image
+        if: ${{ github.event_name != 'pull_request' }}
+        env:
+          # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
+          TAGS: ${{ steps.meta.outputs.tags }}
+          DIGEST: ${{ steps.build-and-push.outputs.digest }}
+        # This step uses the identity token to provision an ephemeral certificate
+        # against the sigstore community Fulcio instance.
+        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}