Add attestation

.github/workflows/build.yml

@@ -6,6 +6,7 @@ on:
     types: [ published ]
 
 env:
+  REGISTRY: docker.io
   REPO: cashtrack/website
 
 jobs:
@@ -14,6 +15,8 @@ jobs:
     permissions:
       contents: read
       packages: write
+      id-token: write
+      attestations: write
 
     steps:
       - name: Checkout repository
@@ -41,8 +44,8 @@ jobs:
             type=sha
             type=semver,pattern={{version}}
 
-        # Setup BuildX
-        # https://github.com/docker/setup-buildx-action
+      # Setup BuildX
+      # https://github.com/docker/setup-buildx-action
       - name: Setup BuildX
         uses: docker/setup-buildx-action@v3
         id: buildx
@@ -53,8 +56,17 @@ jobs:
       # https://github.com/docker/build-push-action
       - name: Build and push
         uses: docker/build-push-action@v6
+        id: push
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+
+      - name: Attest
+        uses: actions/attest-build-provenance@v1
+        id: attest
+        with:
+          subject-name: ${{ env.REGISTRY }}/${{ env.REPO }}
+          subject-digest: ${{ steps.push.outputs.digest }}
+          push-to-registry: true