Use GitHub Actions gha cache for Docker builds

Signed-off-by: Andrew Seigner <[email protected]>

.github/actions/docker-build/action.yml

@@ -30,15 +30,8 @@ inputs:
 runs:
   using: composite
   steps:
-    - name: Configure cache
-      shell: bash
-      run: echo "DOCKER_BUILDKIT_CACHE=${{ runner.temp }}/.buildx-cache" >> $GITHUB_ENV
-    - uses: actions/cache@704facf57e6136b1bc63b828d79edcd491f0ee84
-      with:
-        path: ${{ env.DOCKER_BUILDKIT_CACHE }}
-        key: ${{ runner.os }}-buildx-${{ inputs.component }}-${{ inputs.tag }}
-        restore-keys: ${{ runner.os }}-buildx-${{ inputs.component }}-
-
+    # populate ACTIONS_CACHE_URL, ACTIONS_RUNTIME_TOKEN
+    - uses: crazy-max/ghaction-github-runtime@b3a9207c0e1ef41f4cf215303c976869d0c2c1c4
     - uses: docker/setup-qemu-action@68827325e0b33c7199eb31dd4e31fbe9023e06e3
     - uses: docker/setup-buildx-action@f95db51fddba0c2d1ec667646a06c2ce06100226
     - name: Run bin/docker-build-${{ inputs.component }}
@@ -62,10 +55,6 @@ runs:
         echo "${image_digest}"
         echo "DIGEST=${{ inputs.docker-registry }}/${{ inputs.component }}@${image_digest}" >> "$GITHUB_OUTPUT"
 
-    # Delete older docker images to prevent cache bloat.
-    - run: bin/docker-cache-prune
-      shell: bash
-
 outputs:
   image:
     description: The image that was built

.github/workflows/integration.yml

@@ -18,6 +18,7 @@ on:
       - '!.devcontainer/**'
       - rust-toolchain.toml
       - bin/rust-toolchain-version
+      - bin/_docker.sh
 
 permissions:
   contents: read
@@ -391,4 +392,3 @@ jobs:
           just linkerd-tag='${{ needs.tag.outputs.tag }}' \
               k3d-k8s='${{ matrix.k8s }}' \
               mc-test-run
-

bin/_docker.sh

@@ -18,6 +18,9 @@ export DOCKER_REGISTRY=${DOCKER_REGISTRY:-cr.l5d.io/linkerd}
 # buildx cache directory
 export DOCKER_BUILDKIT_CACHE=${DOCKER_BUILDKIT_CACHE:-}
 
+# populated in GitHub Actions
+export ACTIONS_CACHE_URL=${ACTIONS_CACHE_URL:-}
+
 export DOCKER_TARGET=${DOCKER_TARGET:-$(os)}
 
 # When set together with DOCKER_TARGET=multi-arch, it will push the multi-arch images to the registry
@@ -69,6 +72,8 @@ docker_build() {
 
     if [ "$DOCKER_BUILDKIT_CACHE" ]; then
       cache_params="--cache-from type=local,src=${DOCKER_BUILDKIT_CACHE} --cache-to type=local,dest=${DOCKER_BUILDKIT_CACHE},mode=max"
+    elif [ "$ACTIONS_CACHE_URL" ]; then
+      cache_params="--cache-from type=gha,scope=$name-$DOCKER_TARGET --cache-to type=gha,scope=$name-$DOCKER_TARGET,mode=max"
     fi
 
     output_params="--load"