Update build script for multiarch heroku-24

heroku · Jan 18, 2024 · 6c17f4f · 6c17f4f
1 parent a2ecf31
commit 6c17f4f
Showing 1 changed file with 20 additions and 19 deletions.
diff --git a/bin/build.sh b/bin/build.sh
@@ -16,43 +16,44 @@ write_package_list() {
     docker run --rm "$image_tag" dpkg-query --show --showformat='${Package}\n' >> "$output_file"
 }
 
+RUN_IMAGE_TAG="heroku/heroku:${STACK_VERSION}"
+RUN_DOCKERFILE_DIR="heroku-${STACK_VERSION}"
+
+BUILD_IMAGE_TAG="heroku/heroku:${STACK_VERSION}-build"
+BUILD_DOCKERFILE_DIR="${RUN_DOCKERFILE_DIR}-build"
+
 if [ $STACK_VERSION -ge 24 ]; then
     # heroku/heroku:24 images and beyond are multiarch images. Additionally,
-    # the CNB specific modifications are included, and separate *cnb* variants
-    # do not exist.
+    # the CNB specific modifications are included (separate *cnb* variants
+    # do not exist).
+
+    # NOTE: To build multiarch images with buildx, setup a builder that uses
+    # the `docker-container` driver, and/or turn on the `containerd`
+    # snapshotter storage. https://docs.docker.com/build/building/multi-platform/
 
-    RUN_IMAGE_TAG="heroku/heroku:${STACK_VERSION}"
-    RUN_DOCKERFILE_DIR="heroku-${STACK_VERSION}"
     [[ -d "${RUN_DOCKERFILE_DIR}" ]] || abort "fatal: directory ${RUN_DOCKERFILE_DIR} not found"
-    display "Building ${RUN_DOCKERFILE_DIR} / ${RUN_IMAGE_TAG} Heroku runtime image"
+    display "Building ${RUN_DOCKERFILE_DIR} / ${RUN_IMAGE_TAG} Heroku runtime multiarch image"
     docker buildx build --platform "linux/amd64,linux/arm64" --pull --tag "${RUN_IMAGE_TAG}" "${RUN_DOCKERFILE_DIR}" | indent
     write_package_list "${RUN_IMAGE_TAG}" "${RUN_DOCKERFILE_DIR}"
 
-
-    BUILD_IMAGE_TAG="heroku/heroku:${STACK_VERSION}"
-    BUILD_DOCKERFILE_DIR="heroku-${STACK_VERSION}"
+    # The --pull option is not used for variants to ensure they are based on the
+    # runtime stack image built above, rather than the one last published to DockerHub.
     [[ -d "${BUILD_DOCKERFILE_DIR}" ]] || abort "fatal: directory ${BUILD_DOCKERFILE_DIR} not found"
-    display "Building ${BUILD_DOCKERFILE_DIR} / ${BUILD_IMAGE_TAG} Heroku build-time image"
-    docker buildx build --platform "linux/amd64" --tag "${BUILD_IMAGE_TAG}" "${BUILD_DOCKERFILE_DIR}" | indent
-    write_package_list "${AMD_BUILD_IMAGE_TAG}" "${BUILD_DOCKERFILE_DIR}"
-
+    display "Building ${BUILD_DOCKERFILE_DIR} / ${BUILD_IMAGE_TAG} Heroku build-time multiarch image"
+    docker buildx build --platform "linux/amd64,linux/arm64" --tag "${BUILD_IMAGE_TAG}" "${BUILD_DOCKERFILE_DIR}" | indent
+    write_package_list "${BUILD_IMAGE_TAG}" "${BUILD_DOCKERFILE_DIR}"
 else
     # heroku/heroku:22 and prior does not support multiple chip architectures
-    # or multiarch images. Additionally, they include *cnb* variants that
-    # are separate from variants targeted at heroku classic.
+    # or multiarch images. Additionally, separate *cnb* variants are created
+    # which add compatibility for Cloud Native Buildpacks.
 
-    RUN_IMAGE_TAG="heroku/heroku:${STACK_VERSION}"
-    RUN_DOCKERFILE_DIR="heroku-${STACK_VERSION}"
     [[ -d "${RUN_DOCKERFILE_DIR}" ]] || abort "fatal: directory ${RUN_DOCKERFILE_DIR} not found"
     display "Building ${RUN_DOCKERFILE_DIR} / ${RUN_IMAGE_TAG} Heroku runtime image"
     docker build --pull --tag "${RUN_IMAGE_TAG}" "${RUN_DOCKERFILE_DIR}" | indent
     write_package_list "${RUN_IMAGE_TAG}" "${RUN_DOCKERFILE_DIR}"
 
     # The --pull option is not used for variants to ensure they are based on the
     # runtime stack image built above, rather than the one last published to DockerHub.
-
-    BUILD_IMAGE_TAG="${RUN_IMAGE_TAG}-build"
-    BUILD_DOCKERFILE_DIR="${RUN_DOCKERFILE_DIR}-build"
     display "Building ${BUILD_DOCKERFILE_DIR} / ${BUILD_IMAGE_TAG} Heroku build-time image"
     docker build --tag "$BUILD_IMAGE_TAG" "$BUILD_DOCKERFILE_DIR" | indent
     write_package_list "$BUILD_IMAGE_TAG" "$BUILD_DOCKERFILE_DIR"