mp builds on different runners

Author: danschmidt5189

.github/workflows/build.yml

@@ -10,10 +10,29 @@ env:
   DOCKER_METADATA_SET_OUTPUT_ENV: 'true'
 
 jobs:
-  build:
+  meta:
     runs-on: ubuntu-latest
     outputs:
-      build-image: ${{ steps.build-meta.outputs.tags }}
+      build-labels: ${{ steps.build-meta.outputs.labels }}
+      build-tags: ${{ steps.build-meta.outputs.tags }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Produce the build image tag
+        id: build-meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository }}
+          tags: type=sha,suffix=-build-${{ github.run_id }}_${{ github.run_attempt }}
+
+  build:
+    needs:
+      - meta
+    strategy:
+      matrix:
+        runner: ['ubuntu-latest', 'macos-latest']
+    runs-on: ${{ matrix.runner }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -31,32 +50,25 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Produce the build image tag
-        id: build-meta
-        uses: docker/metadata-action@v5
-        with:
-          images: ghcr.io/${{ github.repository }}
-          tags: type=sha,suffix=-build-${{ github.run_id }}_${{ github.run_attempt }}
-
       - name: Build and push the untested image
         uses: docker/build-push-action@v6
         with:
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
-          labels: ${{ steps.build-meta.outputs.labels }}
-          platforms: linux/amd64,linux/arm64
+          cache-from: type=registry,ref=${{ github.repository }}:cache-${{ matrix.runner }}
+          cache-to: type=registry,ref=${{ github.repository }}:cache-${{ matrix.runner }},mode=max
+          labels: ${{ needs.meta.outputs.build-labels }}
           provenance: true
           push: true
           sbom: true
-          tags: ${{ steps.build-meta.outputs.tags }}
+          tags: ${{ needs.meta.outputs.build-tags }}
 
   test:
     runs-on: ubuntu-latest
     needs:
+      - meta
       - build
     env:
       COMPOSE_FILE: docker-compose.yml:docker-compose.ci.yml
-      DOCKER_APP_IMAGE: ${{ needs.build.outputs.build-image }}
+      DOCKER_APP_IMAGE: ${{ needs.meta.outputs.build-tags }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -80,10 +92,11 @@ jobs:
   push:
     runs-on: ubuntu-latest
     needs:
+      - meta
       - build
       - test
     env:
-      DOCKER_APP_IMAGE: ${{ needs.build.outputs.build-image }}
+      DOCKER_APP_IMAGE: ${{ needs.meta.outputs.build-tags }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v4