From c2e5f692d7f90f093d5481571fca882d69cf83cb Mon Sep 17 00:00:00 2001
From: hyperpolymath <6759885+hyperpolymath@users.noreply.github.com>
Date: Thu, 25 Jun 2026 09:12:50 +0100
Subject: [PATCH] feat(ci): attest build provenance

Adds actions/attest-build-provenance@v2 (SHA-pinned) after the container
build-push step, with id-token+attestations job permissions and the image
digest captured via the build-push step id. Additive only.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .github/workflows/publish-container.yml | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/.github/workflows/publish-container.yml b/.github/workflows/publish-container.yml
index 0997339..7c5d4c4 100644
--- a/.github/workflows/publish-container.yml
+++ b/.github/workflows/publish-container.yml
@@ -10,6 +10,11 @@ permissions:
 jobs:
   publish:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      id-token: write       # mint the OIDC token the attestation is signed with
+      attestations: write   # write the build-provenance attestation (the "claim")
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
       - name: Log in to GitHub Container Registry
@@ -29,6 +34,7 @@ jobs:
             type=semver,pattern={{major}}
             type=sha
       - name: Build and push
+        id: push
         uses: docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf # v6
         with:
           context: .
@@ -36,3 +42,9 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+      - name: Attest container provenance
+        uses: actions/attest-build-provenance@e8998f949152b193b063cb0ec769d69d929409be # v2
+        with:
+          subject-name: ghcr.io/${{ github.repository }}
+          subject-digest: ${{ steps.push.outputs.digest }}
+          push-to-registry: true