Pretty big cache

Description

The cache can grow very quickly with large images, since old entries are not deleted.

Configuration

• Repository URL (if public): https://github.com/MarcelCoding/docker-desktop-vnc/blob/02fb4a97d5a75e40c467b856538efa443d1077cc/.github/workflows/docker-publish.yml#L28-L60
• Build URL (if public): https://github.com/MarcelCoding/docker-desktop-vnc/runs/1549446282?check_suite_focus=true#logs

[...]

      - name: Cache Docker layers
        uses: actions/cache@v2
        with:
          path: /tmp/.buildx-cache
          key: ${{ runner.os }}-buildx-${{ github.sha }}
          restore-keys: |
            ${{ runner.os }}-buildx-

[...]

      - name: Build
        uses: docker/build-push-action@v2
        with:
          push: false
          tags: ${{ steps.prepare.outputs.image }}
          platforms: ${{ env.DOCKER_PLATFORMS }}
          cache-from: type=local,src=/tmp/.buildx-cache
          cache-to: type=local,dest=/tmp/.buildx-cache
          context: .

[...]

Logs

logs_37.zip

My solution

Add a clean-cache configuration option that runs the following command before exporting the layers docker system prune -f --filter "until=5h".

[crazy-max]

@MarcelCoding

The cache can grow very quickly with large images, since old entries are not deleted.

Yes you’re right atm caches are copied over the existing cache so it keeps growing. Can you open an issue on buildkit repo about that please? In the meantime you can do this:

[...]

      - name: Cache Docker layers
        uses: actions/cache@v2
        with:
          path: /tmp/.buildx-cache
          key: ${{ runner.os }}-buildx-${{ github.sha }}
          restore-keys: |
            ${{ runner.os }}-buildx-

[...]

      - name: Build
        uses: docker/build-push-action@v2
        with:
          push: false
          tags: ${{ steps.prepare.outputs.image }}
          platforms: ${{ env.DOCKER_PLATFORMS }}
          cache-from: type=local,src=/tmp/.buildx-cache
          cache-to: type=local,dest=/tmp/.buildx-cache-new
          context: .

[...]

      - name: Move cache
        run:
          rm -rf /tmp/.buildx-cache
          mv /tmp/.buildx-cache-new /tmp/.buildx-cache

cc. @tonistiigi

[ksurl]

does this mean I can remove my step for local cache setup and just use:

      - name: Checkout repo
        uses: actions/checkout@v2
      
      - name: Prepare docker image name
        id: image_names
        run: |
          IMAGES="${GITHUB_REPOSITORY/docker-/},ghcr.io/${GITHUB_REPOSITORY/docker-/}"
          echo ::set-output name=images::${IMAGES}

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v3
        with:
          images: ${{ steps.image_names.outputs.images }}
          tags: |
            type=ref,event=tag

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v1
        with:
          platforms: all

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v1

      #- name: Set up build cache
        #uses: actions/cache@v2
        #with:
          #path: /tmp/.buildx-cache
          #key: ${{ runner.os }}-buildx-${{ github.sha }}
          #restore-keys: |
            #${{ runner.os }}-buildx-

      - name: Login to GitHub
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v1
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GHCR_TOKEN }}

      - name: Login to DockerHub
        uses: docker/login-action@v1
        with:
          username: ${{ secrets.DOCKER_HUB_USERNAME }}
          password: ${{ secrets.DOCKER_HUB_TOKEN }}

      - name: Build image
        id: docker_build
        uses: docker/build-push-action@v2
        with:
          context: ./
          file: ./Dockerfile
          builder: ${{ steps.buildx.outputs.name }}
          push: true
          platforms: linux/amd64,linux/arm/v7,linux/arm64
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          #cache-from: type=local,src=/tmp/.buildx-cache
          cache-from: type=gha, scope=${{ github.workflow }}
          cache-to: type=gha, scope=${{ github.workflow }}
          #cache-to: type=local,dest=/tmp/.buildx-cache