Unify inject and extract into a single action

Signed-off-by: Akihiro Suda <[email protected]>

.github/workflows/test.yml

@@ -0,0 +1,45 @@
+---
+name: Test
+on:
+ push:
+ pull_request:
+jobs:
+ test:
+ runs-on: ubuntu-22.04
+ timeout-minutes: 10
+ steps:
+ - uses: actions/checkout@v4
+ - uses: docker/setup-buildx-action@v2
+ - uses: docker/metadata-action@v4
+ id: meta
+ with:
+ images: test
+ - name: Cache var-cache-apt
+ uses: actions/cache@v3
+ with:
+ path: var-cache-apt
+ key: var-cache-apt-${{ hashFiles('.github/workflows/test/Dockerfile') }}
+ - name: Cache var-lib-apt
+ uses: actions/cache@v3
+ with:
+ path: var-lib-apt
+ key: var-lib-apt-${{ hashFiles('.github/workflows/test/Dockerfile') }}
+ - name: inject var-cache-apt into docker
+ uses: ./
+ with:
+ cache-source: var-cache-apt
+ cache-target: /var/cache/apt
+ - name: inject var-lib-apt into docker
+ uses: ./
+ with:
+ cache-source: var-lib-apt
+ cache-target: /var/lib/apt
+ - name: Build and push
+ uses: docker/build-push-action@v3
+ with:
+ context: .github/workflows/test
+ cache-from: type=gha
+ cache-to: type=gha,mode=max
+ push: false
+ tags: ${{ steps.meta.outputs.tags }}
+ labels: ${{ steps.meta.outputs.labels }}

.github/workflows/test/Dockerfile

@@ -0,0 +1,8 @@
+FROM ubuntu:22.04
+RUN rm -f /etc/apt/apt.conf.d/docker-clean && \
+ echo 'Binary::apt::APT::Keep-Downloaded-Packages "true";' > /etc/apt/apt.conf.d/keep-cache
+RUN \
+ --mount=type=cache,target=/var/cache/apt,sharing=locked \
+ --mount=type=cache,target=/var/lib/apt,sharing=locked \
+ apt update && \
+ apt-get --no-install-recommends install -y gcc

README.md

@@ -40,8 +40,8 @@ jobs:
  path: go-build-cache
  key: ${{ runner.os }}-go-build-cache-${{ hashFiles('**/go.sum') }}
 
- - name: inject go-build-cache into docker
- uses: reproducible-containers/buildkit-cache-dance/inject@main
+ - name: inject/extract go-build-cache into docker
+ uses: reproducible-containers/buildkit-cache-dance@main
  with:
  cache-source: go-build-cache
 
@@ -56,12 +56,6 @@ jobs:
  tags: ${{ steps.meta.outputs.tags }}
  labels: ${{ steps.meta.outputs.labels }}
  platforms: linux/amd64,linux/arm64
-
- - name: extract go-build-cache from docker
- uses: overmindtech/buildkit-cache-dance/extract@main
- with:
- cache-source: go-build-cache
-
 ```
 
 Thanks to [Alexander Pravdin](https://github.com/speller) for the basic idea in [this comment](https://github.com/moby/buildkit/issues/1512).

action.yml

@@ -0,0 +1,58 @@
+name: Inject/Extract Cache
+description: "Injects the cached data into the docker build(x|kit) process"
+inputs:
+ cache-source:
+ default: cache
+ description: "Where the cache is stored in the calling workspace. Default: `cache`"
+ cache-target:
+ default: /root/.cache/go-build
+ description: "Where the cache is stored in the docker container. Default: `/root/.cache/go-build`"
+ scratch-dir:
+ default: scratch
+ description: "Where the action is stores some temporary files for its processing. Default: `scratch`"
+runs:
+ using: composite
+ steps:
+ - uses: pyTooling/Actions/with-post-step@adef08d3bdef092282614f3b683897cefae82ee3 # v0.4.6
+ with:
+ main: |-
+ set -eux
+ # Clean Directories
+ rm -Rf ${{ inputs.scratch-dir }} && mkdir -p ${{ inputs.scratch-dir }} ${{ inputs.cache-source }}
+ # Prepare Timestamp for Layer Cache Busting
+ date --iso=ns | tee ${{ inputs.cache-source }}/buildstamp
+ # Prepare Dancefile to Access Caches
+ cat > ${{ inputs.scratch-dir }}/Dancefile.inject <<EOF
+ FROM busybox:1
+ COPY buildstamp buildstamp
+ RUN --mount=type=cache,target=${{ inputs.cache-target }} \
+ --mount=type=bind,source=.,target=/var/dance-cache \
+ cp -p -R /var/dance-cache/. ${{ inputs.cache-target }} || true
+ EOF
+ cat ${{ inputs.scratch-dir }}/Dancefile.inject
+ # Inject Data into Docker Cache
+ docker buildx build -f ${{ inputs.scratch-dir }}/Dancefile.inject --tag dance:inject ${{ inputs.cache-source }}
+ # Clean Directories
+ sudo rm -rf ${{ inputs.cache-source }}
+ post: |-
+ set -eux
+ # Prepare Timestamp for Layer Cache Busting
+ date --iso=ns | tee ${{ inputs.scratch-dir }}/buildstamp
+ # Prepare Dancefile to Access Caches
+ cat > ${{ inputs.scratch-dir }}/Dancefile.extract <<EOF
+ FROM busybox:1
+ COPY buildstamp buildstamp
+ RUN --mount=type=cache,target=${{ inputs.cache-target }} \
+ mkdir -p /var/dance-cache/ \
+ && cp -p -R ${{ inputs.cache-target }}/. /var/dance-cache/ || true
+ EOF
+ cat ${{ inputs.scratch-dir }}/Dancefile.extract
+ # Extract Data into Docker Image
+ docker buildx build -f ${{ inputs.scratch-dir }}/Dancefile.extract --tag dance:extract --load ${{ inputs.scratch-dir }}
+ # Create Extraction Image
+ docker rm -f cache-container && docker create -ti --name cache-container dance:extract
+ # Unpack Docker Image into Scratch
+ docker cp -L cache-container:/var/dance-cache - | tar -H posix -x -C ${{ inputs.scratch-dir }}
+ # Move Cache into Its Place
+ sudo rm -rf ${{ inputs.cache-source }}
+ mv ${{ inputs.scratch-dir }}/dance-cache ${{ inputs.cache-source }}