Add buildx example with cache

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>

Author: sagikazarmark

.github/workflows/dockerimage.yml

@@ -66,3 +66,20 @@ jobs:
       - run: docker pull docker.pkg.github.com/$GITHUB_REPOSITORY/build-cache-no-buildkit || true
       - run: docker build . -t thing --cache-from=docker.pkg.github.com/$GITHUB_REPOSITORY/build-cache-no-buildkit
       - run: docker tag thing docker.pkg.github.com/$GITHUB_REPOSITORY/build-cache-no-buildkit && docker push docker.pkg.github.com/$GITHUB_REPOSITORY/build-cache-no-buildkit || true
+  build_cache_buildx:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: docker/setup-buildx-action@v1
+      - uses: actions/cache@v2
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ hashFiles('Dockerfile') }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
+      - uses: docker/build-push-action@v2
+        with:
+          push: false
+          tags: thing
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache