Use buildx multi-stage cache (#33)

* Use buildx cache

* Update Makefile

* Use GITHUB_TOKEN

.github/workflows/docker.yaml

@@ -27,11 +27,17 @@ jobs:
       - uses: actions/checkout@v2
       - uses: docker/setup-qemu-action@v1
       - uses: docker/setup-buildx-action@v1
+      - uses: actions/cache@v2
+        with:
+          path: /tmp/buildx
+          key: buildx-${{ runner.os }}-${{ github.sha }}
+          restore-keys: |
+            buildx-${{ runner.os }}-
       - uses: docker/login-action@v1
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
-          password: ${{ secrets.CR_PAT }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - run: make docker-build
         if: github.event_name == 'pull_request'
       - run: make docker-build-push

Makefile

@@ -41,16 +41,19 @@ DOCKER_REPOSITORY := ghcr.io/int128/slack-docker
 .PHONY: docker-build
 docker-build: Dockerfile
 	docker buildx build . \
-		--cache-from=type=registry,ref=$(DOCKER_REPOSITORY):latest \
+		--output=type=image,push=false \
+		--cache-from=type=local,src=/tmp/buildx \
+		--cache-to=type=local,mode=max,dest=/tmp/buildx.new \
 		--platform=linux/amd64,linux/arm64
+	rm -fr /tmp/buildx
+	mv /tmp/buildx.new /tmp/buildx
 
 .PHONY: docker-build-push
 docker-build-push: Dockerfile
 	docker buildx build . \
 		--build-arg=VERSION=$(VERSION) \
 		--tag=$(DOCKER_REPOSITORY):$(VERSION) \
-		--cache-from=type=registry,ref=$(DOCKER_REPOSITORY):latest \
-		--cache-to=type=inline \
+		--cache-from=type=local,src=/tmp/buildx \
 		--platform=linux/amd64,linux/arm64 \
 		--push