[guestbook-go] Use multi-stage build (#211)

guestbook-go/Dockerfile

@@ -12,13 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM busybox:ubuntu-14.04
-
-ADD ./guestbook_bin /app/guestbook
-ADD ./public/index.html /app/public/index.html
-ADD ./public/script.js /app/public/script.js
-ADD ./public/style.css /app/public/style.css
+FROM golang:1.10.0
+RUN go get github.com/codegangsta/negroni \
+           github.com/gorilla/mux \
+           github.com/xyproto/simpleredis
+WORKDIR /app
+ADD ./main.go .
+RUN CGO_ENABLED=0 GOOS=linux go build -o main .
 
+FROM scratch
 WORKDIR /app
-CMD ["./guestbook"]
+COPY --from=0 /app/main .
+COPY ./public/index.html public/index.html
+COPY ./public/script.js public/script.js
+COPY ./public/style.css public/style.css
+CMD ["/app/main"]
 EXPOSE 3000

guestbook-go/Makefile

@@ -23,19 +23,14 @@ release: clean build push clean
 
 # builds a docker image that builds the app and packages it into a minimal docker image
 build:
-	@cp ../../bazel-bin/examples/guestbook-go/guestbook-go guestbook_bin
-	docker build --pull --rm --force-rm -t ${REGISTRY}/guestbook-builder .
-	docker run --rm ${REGISTRY}/guestbook-builder | docker build --pull -t "${REGISTRY}/guestbook:${VERSION}" -
+	docker build -t ${REGISTRY}/guestbook:${VERSION} .
 
 # push the image to an registry
 push:
 	gcloud docker -- push ${REGISTRY}/guestbook:${VERSION}
 
 # remove previous images and containers
 clean:
-	rm -f guestbook_bin
-	docker rm -f ${REGISTRY}/guestbook-builder 2> /dev/null || true
-	docker rmi -f ${REGISTRY}/guestbook-builder || true
-	docker rmi -f "${REGISTRY}/guestbook:${VERSION}" || true
+	docker rm -f ${REGISTRY}/guestbook:${VERSION} 2> /dev/null || true
 
 .PHONY: release clean build push