Inside Bitcoin

1name: 'Configure Docker'
2description: 'Set up Docker build driver and configure build cache args'
3inputs:
4  provider:
5    description: 'The cache provider to use'
6    required: false
7    default: 'gha'
8runs:
9  using: 'composite'
10  steps:
11    - name: Set up Docker Buildx for Warp cache
12      if: ${{ inputs.provider == 'warp' }}
13      uses: docker/setup-buildx-action@v4
14      with:
15        driver-opts: |
16          network=host
17          env.BUILDKIT_STEP_LOG_MAX_SIZE=5242880
18
19    - name: Set up Docker Buildx
20      if: ${{ inputs.provider != 'warp' }}
21      uses: docker/setup-buildx-action@v4
22      with:
23        driver-opts: |
24          env.BUILDKIT_STEP_LOG_MAX_SIZE=5242880
25
26    # This is required when using the gha cache backend with a manual docker buildx invocation.
27    # Docker will check for variables $ACTIONS_CACHE_URL, $ACTIONS_RESULTS_URL and $ACTIONS_RUNTIME_TOKEN
28    # which are set automatically when running on GitHub infra: https://docs.docker.com/build/cache/backends/gha/#synopsis
29    - name: Expose actions cache variables
30      uses: actions/github-script@v8
31      with:
32        script: |
33          Object.keys(process.env).forEach(function (key) {
34            if (key.startsWith('ACTIONS_')) {
35              core.info(`Exporting ${key}`);
36              core.exportVariable(key, process.env[key]);
37            }
38          });
39
40    - name: Construct docker build cache args
41      shell: bash
42      run: |
43        cache_options="scope=${CONTAINER_NAME}"
44        if [[ "${{ inputs.provider }}" == "warp" ]]; then
45          cache_options="url=http://127.0.0.1:49160/,version=1,${cache_options}"
46        fi
47
48        # Configure docker build cache backend
49        # Always optimistically --cache‑from in case a cache blob exists
50        args=(--cache-from "type=gha,${cache_options}")
51
52        # Only add --cache-to when pushing to the default branch.
53        if [[ ${{ github.event_name }} == "push" && ${{ github.ref_name }} == ${{ github.event.repository.default_branch }} ]]; then
54          args+=(--cache-to "type=gha,mode=max,ignore-error=true,${cache_options}")
55        fi
56
57        # Always `--load` into docker images (needed when using the `docker-container` build driver).
58        args+=(--load)
59
60        echo "DOCKER_BUILD_CACHE_ARG=${args[*]}" >> $GITHUB_ENV
61