From 4f7a2cefd311ed25a512d36e6fcc5638f6ac872f Mon Sep 17 00:00:00 2001
From: Aaron Reisman <aaron@reisman.org>
Date: Tue, 22 Oct 2024 00:56:48 -0500
Subject: [PATCH] push as digest

---
 .github/workflows/docker.yml | 83 ++++++++++++++++++++++++++++++------
 1 file changed, 71 insertions(+), 12 deletions(-)

diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index d5ebf516..69c1c158 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -20,8 +20,11 @@ on:
       docker_token:
         required: true
 
+env:
+  REGISTRY_IMAGE: ${{ secrets.docker_username }}/libation
+
 jobs:
-  build_and_push:
+  build:
     runs-on: ubuntu-latest
     strategy:
       # Prevent a failure in one image from stopping the other builds
@@ -29,12 +32,14 @@ jobs:
       matrix:
         os: 
           - ubuntu-latest
-        arch:
+        platform:
           - amd64
           - arm64
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
+      - name: Prepare
+        run: |
+          platform=${{ matrix.platform }}
+          echo "PLATFORM_PAIR=linux-${platform}" >> $GITHUB_ENV   
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
@@ -52,21 +57,75 @@ jobs:
         id: metadata
         uses: docker/metadata-action@v5
         with:
-          flavor: |
-            latest=true
           images: |
-            name=${{ secrets.docker_username }}/libation
-          tags: |
-            type=raw,value=${{ inputs.version }},enable=${{ inputs.release }}
+            name=${{ env.REGISTRY_IMAGE }}
 
-      - name: Build and push image
+      - name: Build and push by digest 
         uses: docker/build-push-action@v6
         with:
           platforms: ${{ matrix.arch }}
-          push: ${{ steps.metadata.outputs.tags != ''}}
           cache-from: type=gha
           cache-to: type=gha,mode=max
           tags: ${{ steps.metadata.outputs.tags }}
           labels: ${{ steps.metadata.outputs.labels }}
           build-args: |
-            TARGETARCH=${{ matrix.arch }}
+            TARGETARCH=${{ matrix.platform }}
+          outputs: type=image,name=${{ env.REGISTRY_IMAGE }},push-by-digest=true,name-canonical=true,push=${{ inputs.release }}
+
+      - name: Export digest
+        run: |
+          mkdir -p /tmp/digests
+          digest="${{ steps.build.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"          
+      
+      - name: Upload digest
+        uses: actions/upload-artifact@v4
+        with:
+          name: digests-${{ env.PLATFORM_PAIR }}
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+  merge:
+    runs-on: ubuntu-latest
+    if: ${{ inputs.release }}
+    needs:
+      - build
+    steps:
+      - name: Download digests
+        uses: actions/download-artifact@v4
+        with:
+          path: /tmp/digests
+          pattern: digests-*
+          merge-multiple: true
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          flavor: |
+            latest=true
+          images: |
+            name=${{ secrets.docker_username }}/libation
+          tags: |
+            type=raw,value=${{ inputs.version }},enable=${{ inputs.release }}
+
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.docker_username }}
+          password: ${{ secrets.docker_token }}
+
+      - name: Create manifest list and push
+        working-directory: /tmp/digests
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)
+
+      - name: Inspect image
+        run: |
+          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ steps.meta.outputs.version }}