build: use containerd to load multi-platform images

Author: autumnjolitz

.github/workflows/main.yml

@@ -48,6 +48,10 @@ jobs:
       -
         name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
+      -
+        name: Set up containerd
+        uses: crazy-max/ghaction-setup-containerd@v2
+
       -
         id: image_env
         run: |
@@ -58,6 +62,7 @@ jobs:
             '${{ matrix.repository }}'
 
           docker pull "${SOURCE_IMAGE}" || true
+          echo "IMAGE_HOME=$(mktemp -d)" >> "$GITHUB_OUTPUT"
 
           echo ALPINE_VERSION="${ALPINE_VERSION}" >> "$GITHUB_OUTPUT"
           echo PYTHON_VERSION="${PYTHON_VERSION}" >> "$GITHUB_OUTPUT"
@@ -78,7 +83,10 @@ jobs:
           context: "."
           file: Dockerfile.alpine
           target: buildroot
+          cache-to: |
+            type=gha
           cache-from: |
+            type=gha
             type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot
             type=registry,ref=${{ steps.image_env.outputs.SOURCE_IMAGE }}@${{ steps.image_env.outputs.BASE_IMAGE_DIGEST }}
           build-args: |
@@ -88,6 +96,7 @@ jobs:
               SOURCE_IMAGE=${{ steps.image_env.outputs.SOURCE_IMAGE }}
               BUILD_ROOT=/d
           tags: "${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot"
+          outputs: type=oci,dest=${{ steps.image_env.outputs.IMAGE_HOME }}/buildroot.tar
       -
         name: distroless
         uses: docker/build-push-action@v6
@@ -100,16 +109,28 @@ jobs:
           file: Dockerfile.alpine
           # target: distroless-python
           cache-from: |
+              type=gha
               type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}
               type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot
               type=registry,ref=${{ steps.image_env.outputs.SOURCE_IMAGE }}@${{ steps.image_env.outputs.BASE_IMAGE_DIGEST }}
+          cache-to: |
+              type=gha
           build-args: |
               ALPINE_VERSION=${{ steps.image_env.outputs.ALPINE_VERSION }}
               BASE_IMAGE_DIGEST=${{ steps.image_env.outputs.BASE_IMAGE_DIGEST }}
               PYTHON_VERSION=${{ steps.image_env.outputs.PYTHON_VERSION }}
               SOURCE_IMAGE=${{ steps.image_env.outputs.SOURCE_IMAGE }}
               BUILD_ROOT=/d
           tags: "${{ steps.image_env.outputs.IMAGE_TAG }}"
+          outputs: type=oci,dest=${{ steps.image_env.outputs.IMAGE_HOME }}/image.tar
+
+      -
+        name: Import image in containerd
+        run: |
+          echo 'import 1'
+          skopeo --debug copy 'oci-archive:${{ steps.image_env.outputs.IMAGE_HOME }}/buildroot.tar' 'docker-daemon:${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot'
+          echo 'import 2'
+          skopeo --debug copy 'oci-archive:${{ steps.image_env.outputs.IMAGE_HOME }}/image.tar' 'docker-daemon:${{ steps.image_env.outputs.IMAGE_TAG }}'
 
       -
         name: examples/simple-flask
@@ -121,12 +142,19 @@ jobs:
             linux/arm64/v7
             linux/arm64/v8
           cache-from: |
+              type=gha
               type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}
               type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot
               type=registry,ref=${{ steps.image_env.outputs.SOURCE_IMAGE }}@${{ steps.image_env.outputs.BASE_IMAGE_DIGEST }}
           build-args: |
               SOURCE_IMAGE=${{ steps.image_env.outputs.IMAGE_TAG }}
           tags: "${{ steps.image_env.outputs.IMAGE_TAG }}-example1-amd64"
+          outputs: type=oci,dest=${{ steps.image_env.outputs.IMAGE_HOME }}/example1.tar
+
+      -
+        name: Import image in containerd
+        run: |
+          sudo ctr images import --base-name '${{ steps.image_env.outputs.IMAGE_TAG }}-example1-amd64' --digests --all-platforms '${{ steps.image_env.outputs.IMAGE_HOME }}/example1.tar'
 
       -
         name: Login to GitHub Container Registry
@@ -157,7 +185,10 @@ jobs:
           context: "."
           file: Dockerfile.alpine
           target: buildroot
+          cache-to: |
+            type=gha
           cache-from: |
+            type=gha
             type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot
             type=registry,ref=${{ steps.image_env.outputs.SOURCE_IMAGE }}@${{ steps.image_env.outputs.BASE_IMAGE_DIGEST }}
           build-args: |
@@ -180,7 +211,10 @@ jobs:
             linux/arm64/v7
             linux/arm64/v8
           file: Dockerfile.alpine
+          cache-to: |
+              type=gha
           cache-from: |
+              type=gha
               type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}
               type=registry,ref=${{ steps.image_env.outputs.IMAGE_TAG }}-buildroot
               type=registry,ref=${{ steps.image_env.outputs.SOURCE_IMAGE }}@${{ steps.image_env.outputs.BASE_IMAGE_DIGEST }}