Build docker image in CI

.github/workflows/continuous_delivery.yaml

@@ -29,11 +29,14 @@ jobs:
     - name: Build
       run: make build
 
+    - name: Build docker image
+      run: make image
+
     - name: Lint
       run: make lint
 
     - name: Test
-      run: git show && make testci
+      run: git show --stat && make testci
 
     - name: Code coverage
       uses: codecov/codecov-action@v1

Dockerfile

+# syntax = docker/dockerfile:1-experimental
 FROM golang:1.16
 
 WORKDIR /go/src/github.com/mccutchen/go-httpbin
@@ -6,7 +7,8 @@ WORKDIR /go/src/github.com/mccutchen/go-httpbin
 RUN cd /tmp && go get -u github.com/kevinburke/go-bindata/...
 
 COPY . .
-RUN make build buildtests
+RUN --mount=type=cache,id=gobuild,target=/root/.cache/go-build \
+    make build buildtests
 
 FROM gcr.io/distroless/base
 COPY --from=0 /go/src/github.com/mccutchen/go-httpbin/dist/go-httpbin* /bin/

Makefile

@@ -142,7 +142,7 @@ gcloud-auth:
 # docker images
 # =============================================================================
 image:
-	docker build -t $(DOCKER_TAG_DOCKERHUB) .
+	DOCKER_BUILDKIT=1 docker build -t $(DOCKER_TAG_DOCKERHUB) .
 
 imagepush: image
 	docker push $(DOCKER_TAG_DOCKERHUB)