Add pack cli project.toml descriptior for collecting build files

Add dockerfiles and scripts

Add github aworkflows for prs and release

.github/workflows/pull_request.yml

@@ -0,0 +1,16 @@
+name: Build and push to local registry
+on: pull_request
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+        with:
+          platforms: linux/amd64,linux/arm64
+      - uses: buildpacks/github-actions/[email protected]
+      - uses: buildpacks/github-actions/[email protected]
+      - id: local-registry-push
+        run: |
+          ./pack-with-buildkit.sh

.github/workflows/release.yml

@@ -0,0 +1,27 @@
+name: Build and push to ghcr.io
+on:
+  push:
+    branches:
+      - "main"
+env:
+  PUBLISH_TO_GHCR_IO_IMAGE_URI: ghcr.io/jericop/inline-app:latest
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+        with:
+          platforms: linux/amd64,linux/arm64
+      - uses: buildpacks/github-actions/[email protected]
+      - uses: buildpacks/github-actions/[email protected]
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GHCR_TOKEN }}
+      - id: ghcr-push
+        run: |
+          ./pack-with-buildkit.sh
+          

.gitignore

@@ -0,0 +1,4 @@
+cnb-build-files
+Dockerfile
+lifecycle-commands.log
+pack-build.log

Dockerfile-example

@@ -0,0 +1,78 @@
+# Pin the lifecycle version so we can be sure of the behavior if we run this script in the future
+FROM chainguard/crane:latest as crane
+FROM buildpacksio/lifecycle:0.16.3 as lifecycle
+FROM ghcr.io/jericop/builder-jammy:latest
+USER root
+
+COPY --from=crane /usr/bin/crane /usr/local/bin/crane
+COPY --from=lifecycle /cnb/lifecycle /cnb/lifecycle
+COPY ./cnb-build-files/cnb/buildpacks /cnb/buildpacks
+COPY ./cnb-build-files/layers /layers
+
+RUN mkdir -p /cache
+RUN chown -R cnb:cnb /workspace /cache
+RUN chown -R cnb:cnb /layers /platform
+RUN find /layers
+
+USER cnb
+
+ENV CNB_PLATFORM_API=0.9
+
+COPY ./ /workspace
+
+WORKDIR /workspace
+
+# Add RUN command(s) below here to run the lifecycle commands and build and export the app to a registry
+# It also fixes the architecture because it always gets set to amd64 when running in buildkit.
+
+RUN <<RUN_EOF
+
+export image_arch=amd64
+if [ $(arch) = "aarch64" ]; then
+  export image_arch=arm64
+fi
+
+export image_uri="localhost:55000/inline-app:$image_arch"
+
+echo "#!/bin/bash" > /workspace/lifecycle-build.sh
+cat <<IN_BUILDKIT_LIFECYCLE_SCRIPT_EOF >> /workspace/lifecycle-build.sh
+
+set -euo pipefail
+set -x
+
+/cnb/lifecycle/analyzer -log-level debug -stack /layers/stack.toml -run-image ghcr.io/jericop/run-jammy:latest localhost:55000/inline-app:$image_arch
+/cnb/lifecycle/detector -app /workspace -log-level debug
+/cnb/lifecycle/restorer -cache-dir /cache -log-level debug
+/cnb/lifecycle/builder -app /workspace -log-level debug
+/cnb/lifecycle/exporter -log-level debug -app /workspace -cache-dir /cache -stack /layers/stack.toml localhost:55000/inline-app:$image_arch
+
+crane pull $image_uri image.tar
+
+mkdir -p contents
+tar -xvf image.tar -C contents
+cd contents
+ls
+cat manifest.json | jq -r '.[0].Config'
+current_config=\$(cat manifest.json | jq -r '.[0].Config')
+echo \$current_config
+cat \$current_config | jq -c ".architecture = \"\${image_arch}\" | .os = \"linux\"" | tr -d '\n' > newconfig.json
+new_config="sha256:$(sha256sum newconfig.json | cut -d' ' -f1)"
+rm -f "\${current_config}"
+mv newconfig.json "\${new_config}"
+cat manifest.json| jq -c ".[0].Config = \"\${new_config}\"" | tr -d '\n' > newmanifest.json
+mv -f newmanifest.json manifest.json
+tar -cvf ../fixed-arch-image.tar *
+cd ..
+
+crane push fixed-arch-image.tar $image_uri
+
+rm -rf image.tar fixed-arch-image.tar contents
+
+IN_BUILDKIT_LIFECYCLE_SCRIPT_EOF
+
+# Run the lifecycle script and ensure correct architecture is set
+chmod +x /workspace/lifecycle-build.sh
+/workspace/lifecycle-build.sh
+
+RUN_EOF
+

Dockerfile-initial

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+# Pin the lifecycle version so we can be sure of the behavior if we run this script in the future
+FROM chainguard/crane:latest as crane
+FROM buildpacksio/lifecycle:0.16.3 as lifecycle
+FROM ghcr.io/jericop/builder-jammy:latest
+USER root
+
+COPY --from=crane /usr/bin/crane /usr/local/bin/crane
+COPY --from=lifecycle /cnb/lifecycle /cnb/lifecycle
+COPY ./cnb-build-files/cnb/buildpacks /cnb/buildpacks
+COPY ./cnb-build-files/layers /layers
+
+RUN mkdir -p /cache
+RUN chown -R cnb:cnb /workspace /cache
+RUN chown -R cnb:cnb /layers /platform
+RUN find /layers
+
+USER cnb
+
+ENV CNB_PLATFORM_API=0.9
+
+COPY ./ /workspace
+
+WORKDIR /workspace
+
+# Add RUN command(s) below here to run the lifecycle commands and build and export the app to a registry
+# It also fixes the architecture because it always gets set to amd64 when running in buildkit.
+

README.md

@@ -1 +1,35 @@
-# cnb-lfx-buildkit-poc
+# cnb-lfx-buildkit-poc
+
+This repo is an initial proof-of-concept for the following LFX mentorship project.
+
+[CNCF - Cloud Native Buildpacks: Proof of concept making multiarch images with buildkit (2024 Term 1)](https://mentorship.lfx.linuxfoundation.org/project/2c5ced86-d23b-41f5-aec3-59730e29f092)
+
+It is heavliy inspired by the following article. While the article is invaluable for understanding how the lifecycle works, it requires a fair amount of manual steps, which must be repeated if any changes are made to buildpacks. For the sake of simplicity, I am using an inline buildpack and running `pack build` once in order to copy out the necessary files.
+
+* https://medium.com/buildpacks/unpacking-cloud-native-buildpacks-ff51b5a767bf
+
+## Primary objective
+
+The primary objective is to create a Dockerfile that has all of the lifecycle commands needed to build and push architecture-specific images to a registry. `Dockerfile-example` is an example of how it works. You can then combine the architecture-specific images into a manifest list (multi-arch) image.
+
+## `pack-with-buildkit.sh`
+
+This script will do the following:
+
+* Sets up a buildkit builder with `host` network access
+* Starts a local registry on a random port
+* Run `pack build` using the `project.toml` which has an inline buildpack that copies the files we need to /workspace
+* Copies the files we need out of the container built with pack so we can use them in a new build (with buildkit)
+* Generates a `Dockerfile` from `Dockerfile-initial` that will look like `Dockerfile-example`
+* Runs `docker buildx build --platform linux/amd64,linux/arm64` to execute the lifecycle commands through buildkit
+  * This builds and publishes images to the local registry with `amd64` and `arm64` tags
+  * There is some hackery that happens to fix the architecture (for now)
+* Finally it creates a manifest list with the `amd64` and `arm64` tagged images
+
+## Requirements
+
+* Multi-arch builders are required. I'm using ones that I build and publish.
+
+## Published image(s)
+
+* ghcr.io/jericop/inline-app:latest

pack-with-buildkit.sh

@@ -0,0 +1,135 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_name="mybuildpack"
+registry_name="local-registry"
+builder_name="${registry_name}"
+
+cleanup() {
+  docker buildx stop "${builder_name}" > /dev/null 2>&1
+  docker buildx rm "${builder_name}" > /dev/null 2>&1
+
+  log_message "Stopping local registry"
+  docker stop "${registry_name}" > /dev/null 2>&1
+}
+
+log_message() {
+  echo "$1"
+}
+
+# https://github.com/docker/buildx/issues/166#issuecomment-1804970076
+# First, we need to create our own buildx builder that uses the host nework and docker-container driver so that we can get multiarch support
+log_message "Setting up docker buildx builder"
+docker buildx use "${builder_name}" > /dev/null 2>&1 || docker buildx create --name "${builder_name}" --driver docker-container --driver-opt network=host --bootstrap --use > /dev/null 2>&1
+
+# Next, we need to check if a registry is already running
+log_message "Setting up a local registry on random port"
+docker container inspect "${registry_name}" > /dev/null 2>&1 || docker run -d -e REGISTRY_STORAGE_DELETE_ENABLED=true -p 0:5000 --rm --name "${registry_name}" registry:2 > /dev/null 2>&1
+
+# Get local registry port since we asked docker to assign a random port by choosing port 0
+registry_port=$(docker inspect "${registry_name}" | jq -r '.[0].NetworkSettings.Ports["5000/tcp"][0].HostPort')
+log_message "Local registry is listening on port ${registry_port}"
+
+# Rather than creating the necessary files manually, we let pack generate and the inline buildpack 
+# copy them to /layers/build-files we publish to a local registry so we can capture 
+pack build localhost:$registry_port/inline-app \
+  --publish --verbose --network host 2>&1 | tee pack-build.log \
+  | grep -B3 -A4 "Args: '/cnb/lifecycle" > lifecycle-commands.log
+
+docker pull localhost:$registry_port/inline-app
+
+if [ -d cnb-build-files ]; then
+  rm -rf cnb-build-files
+fi
+mkdir -p cnb-build-files
+
+# Copy the files created by pack during the build from the volume and into the local directory 
+docker run --rm --entrypoint bash --user root \
+  --volume $(pwd)/cnb-build-files:/hostmnt \
+  localhost:$registry_port/inline-app \
+  -c 'cp -R /workspace/build-files/* /hostmnt/'
+
+# We copy the initial Dockerfile (without lifecycle commands) to Dockerfile
+cp Dockerfile-initial Dockerfile
+
+# Then we add a run command (heredoc) with the lifecycle commands to build and push the architecture-specific images
+cat <<ADD_RUN_COMMAND_TO_DOCKERFILE_EOF >> Dockerfile 
+RUN <<RUN_EOF
+
+export image_arch=amd64
+if [ \$(arch) = "aarch64" ]; then
+  export image_arch=arm64
+fi
+
+export image_uri="localhost:$registry_port/inline-app:\$image_arch"
+
+echo "#!/bin/bash" > /workspace/lifecycle-build.sh
+cat <<IN_BUILDKIT_LIFECYCLE_SCRIPT_EOF >> /workspace/lifecycle-build.sh
+
+set -euo pipefail
+set -x
+
+ADD_RUN_COMMAND_TO_DOCKERFILE_EOF
+
+# Add the lifecycle commands from the saved log output of `pack build` we ran above
+while read cmd; do
+  if echo $cmd | grep -q "localhost:$registry_port/inline-app\$"; then
+    echo "$cmd:\$image_arch" >> Dockerfile
+  else
+    echo "$cmd" >> Dockerfile
+  fi
+done < <(grep Args: lifecycle-commands.log | cut -d"'" -f2)
+
+cat <<'CONTINUE_ADD_RUN_COMMAND_TO_DOCKERFILE_EOF' >> Dockerfile
+
+crane pull $image_uri image.tar
+
+mkdir -p contents
+tar -xvf image.tar -C contents
+cd contents
+ls
+cat manifest.json | jq -r '.[0].Config'
+current_config=\$(cat manifest.json | jq -r '.[0].Config')
+echo \$current_config
+cat \$current_config | jq -c ".architecture = \"\${image_arch}\" | .os = \"linux\"" | tr -d '\n' > newconfig.json
+new_config="sha256:$(sha256sum newconfig.json | cut -d' ' -f1)"
+rm -f "\${current_config}"
+mv newconfig.json "\${new_config}"
+cat manifest.json| jq -c ".[0].Config = \"\${new_config}\"" | tr -d '\n' > newmanifest.json
+mv -f newmanifest.json manifest.json
+tar -cvf ../fixed-arch-image.tar *
+cd ..
+
+crane push fixed-arch-image.tar $image_uri
+
+rm -rf image.tar fixed-arch-image.tar contents
+
+IN_BUILDKIT_LIFECYCLE_SCRIPT_EOF
+
+# Run the lifecycle script and ensure correct architecture is set
+chmod +x /workspace/lifecycle-build.sh
+/workspace/lifecycle-build.sh
+
+RUN_EOF
+
+CONTINUE_ADD_RUN_COMMAND_TO_DOCKERFILE_EOF
+
+# After all of that, we are finally ready to build the multi-arch images using the lifecycle with buildkit.
+# We are not publishing with this command because the lifecyle will publish the images to the local registry for us.
+docker buildx build --tag ignored --platform linux/amd64,linux/arm64 .
+
+# Now we can combine the linux/amd64 and linux/arm64 images into a manifest list and push it to the local registry
+docker buildx imagetools create \
+  --tag localhost:$registry_port/inline-app:latest \
+  localhost:$registry_port/inline-app:amd64 \
+  localhost:$registry_port/inline-app:arm64
+
+crane manifest localhost:$registry_port/inline-app:latest  | jq
+
+if [[ ! -z "${PUBLISH_TO_GHCR_IO_IMAGE_URI:-}" ]]; then
+  crane copy localhost:$registry_port/inline-app:latest ghcr.io/jericop/inline-app:latest
+  log_message "Published image to: $PUBLISH_TO_GHCR_IO_IMAGE_URI"
+fi
+
+# This image can then be copied to another registry

project.toml

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+[project]
+name = "inline-app"
+
+# stack images need to be multi-arch for this to work
+[build]
+builder = "ghcr.io/jericop/builder-jammy:latest"
+
+[[build.buildpacks]]
+id = "inline/shell-buildpack"
+
+[build.buildpacks.script]
+api = "0.8"
+inline = """
+set -x
+
+# sleep 300
+
+build_files=/workspace/build-files
+
+mkdir -p $build_files/cnb
+mkdir -p $build_files/layers
+
+ls /cnb/*.toml
+cp -r /cnb/*.toml $build_files/cnb/
+cp -r /cnb/buildpacks $build_files/cnb/
+
+cp /cnb/order.toml $build_files/layers/ 
+cp /layers/*.toml $build_files/layers/
+
+find $build_files
+
+cat <<EOF > ${1}/launch.toml
+[[processes]]
+type = 'web'
+command = 'bin/bash'
+default = true
+EOF
+"""