chore: adds image signing with cosign to publish.yml (#82)

* chore: adds image signing with cosign to publish.yml Signed-off-by: Jennifer Power <barnabei.jennifer@gmail.com> * chore: add ignore line for KICS false positive Signed-off-by: Jennifer Power <barnabei.jennifer@gmail.com> * fix: update the verification steps to add identity regexp and issuer Adds a regular expression so a consumer can verify that image was published from the expected repository. Signed-off-by: Jennifer Power <barnabei.jennifer@gmail.com> --------- Signed-off-by: Jennifer Power <barnabei.jennifer@gmail.com>
complytime · Dec 13, 2023 · f6f7035 · f6f7035
1 parent 3c68011
commit f6f7035
Showing 1 changed file with 32 additions and 6 deletions.
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
@@ -29,24 +29,34 @@ jobs:
     runs-on: 'ubuntu-latest'
     permissions:
       contents: read
+      # kics-scan ignore-line
+      id-token: write # needed for signing the images with GitHub OIDC Token
     outputs:
       skip_tests: ${{ steps.check_event.outputs.event_type == 'release' ||
                   (steps.check_event.outputs.event_type == 'workflow_dispatch' &&
                   github.event.inputs.skip_tests == 'true') }}
-      image: ${{ env.IMAGE_REGISTRY }}/${{ vars.QUAY_ORG }}/${{ env.IMAGE_NAME }}@${{ steps.build-image.outputs.digest }}
+      image: ${{ steps.set_image_repo.outputs.image_repo }}@${{ steps.build-and-push.outputs.digest }}
     steps:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
+
+      - name: Set up cosign
+        uses: sigstore/cosign-installer@v3.1.1
 
       - name: Login to Quay
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.QUAY_USER }}
           password: ${{ secrets.QUAY_TOKEN }}
           registry: ${{ env.IMAGE_REGISTRY }}
+
+      - name: Set image repository
+        id: set_image_repo
+        run: |
+          echo "image_repo=${{ env.IMAGE_REGISTRY }}/${{ vars.QUAY_ORG }}/${{ env.IMAGE_NAME }}" >> "$GITHUB_OUTPUT"
 
       - name: Check if triggered by release or workflow dispatch
         id: check_event
@@ -72,17 +82,18 @@ jobs:
 
       - name: Build and export to Docker
         uses: docker/build-push-action@v5
+        id: build-and-export
         with:
           load: true
           no-cache: ${{ env.NO_CACHE == 'true' }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
-          tags: ${{ env.IMAGE_REGISTRY }}/${{ vars.QUAY_ORG }}/${{ env.IMAGE_NAME }}:${{ env.TAG }}
+          tags: ${{ steps.set_image_repo.outputs.image_repo }}:${{ env.TAG }}
 
       - name: Pre-push Image Scan
         uses: aquasecurity/trivy-action@0.16.0
         with:
-          image-ref: ${{ env.IMAGE_REGISTRY }}/${{ vars.QUAY_ORG }}/${{ env.IMAGE_NAME }}:${{ env.TAG }}
+          image-ref: ${{ steps.set_image_repo.outputs.image_repo }}:${{ env.TAG }}
           exit-code: 1
           skip-files:  "**/.venv/lib/**/METADATA"
           scanners: secret
@@ -91,10 +102,25 @@ jobs:
       # Does not rebuild. Uses internal cache from previous step.
       - name: Build and Push
         uses: docker/build-push-action@v5
-        id: build-image
+        id: build-and-push
         with:
           push: true
-          tags: ${{ env.IMAGE_REGISTRY }}/${{ vars.QUAY_ORG }}/${{ env.IMAGE_NAME }}:${{ env.TAG }}
+          tags: ${{ steps.set_image_repo.outputs.image_repo }}:${{ env.TAG }}
+
+      - name: Sign the image with GitHub OIDC Token
+        run: cosign sign --yes "$IMAGE@$DIGEST"
+        env:
+          DIGEST: ${{ steps.build-and-push.outputs.digest }}
+          IMAGE: ${{ steps.set_image_repo.outputs.image_repo }}
+
+      - name: Verify image
+        run: |
+          cosign verify "$IMAGE@$DIGEST" --certificate-identity-regexp="$SUBJECT" \
+          --certificate-oidc-issuer=https://token.actions.githubusercontent.com
+        env:
+          SUBJECT: https://github\.com/${{ github.repository_owner }}/trestle-bot/\.github/.+
+          IMAGE: ${{ steps.set_image_repo.outputs.image_repo }}
+          DIGEST: ${{ steps.build-and-push.outputs.digest }}
 
   test:
     permissions:
@@ -103,4 +129,4 @@ jobs:
     if: ${{ needs.publish-image.outputs.skip_tests != 'true' }}
     uses: ./.github/workflows/e2e.yml
     with:
-      image: ${{ needs.publish-image.outputs.image }}
+      image: ${{ needs.publish-image.outputs.image }}