attempt to add cache

build time is currently very slow, lets try to fix it

.github/workflows/docker-publish.yml

@@ -53,6 +53,14 @@ jobs:
       # Workaround: https://github.com/docker/build-push-action/issues/461
       - name: Setup Docker buildx
         uses: docker/setup-buildx-action@dc7b9719a96d48369863986a06765841d7ea23f6
+        
+      - name: Cache Docker layers
+        uses: actions/cache@v2
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
 
       # Login against a Docker registry except on PR
       # https://github.com/docker/login-action
@@ -85,6 +93,8 @@ jobs:
           # https://github.com/docker/setup-qemu-action#about
           # platforms: linux/amd64,linux/arm64,linux/riscv64,linux/ppc64le,linux/s390x,linux/386,linux/mips64le,linux/mips64,linux/arm/v7,linux/arm/v6
           platforms: linux/amd64,linux/arm64,linux/arm/v6,linux/arm/v7
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache-new,mode=max
 
       # Sign the resulting Docker image digest except on PRs.
       # This will only write to the public Rekor transparency log when the Docker
@@ -98,3 +108,12 @@ jobs:
         # This step uses the identity token to provision an ephemeral certificate
         # against the sigstore community Fulcio instance.
         run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign {}@${{ steps.build-and-push.outputs.digest }}
+
+      -
+        # Temp fix
+        # https://github.com/docker/build-push-action/issues/252
+        # https://github.com/moby/buildkit/issues/1896
+        name: Move cache
+        run: |
+          rm -rf /tmp/.buildx-cache
+          mv /tmp/.buildx-cache-new /tmp/.buildx-cache