use multi-stage build image

.github/workflows/build.yml

@@ -66,10 +66,6 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-      - name: get dependency
-        run: go get -t -v ./...
-      - name: build
-        run: make linux
       # Setup gcloud CLI
       - uses: GoogleCloudPlatform/github-actions/setup-gcloud@master
         with:

Dockerfile

@@ -1,5 +1,14 @@
-FROM scratch
+FROM golang:1.14 as builder
+WORKDIR /go/src/cmg
+COPY go.* ./
+RUN go mod download
+COPY . ./
+RUN CGO_ENABLED=0 GOOS=linux go build  -v -o cmg
+
+FROM alpine:3
+RUN apk --no-cache add ca-certificates
 EXPOSE 8080
-ENTRYPOINT ["/cmg"]
+ENV PORT=8080
+ENTRYPOINT ["/usr/bin/cmg"]
 CMD ["serve"]
-COPY ./bin/ /usr/bin
+COPY --from=builder /go/src/cmg/cmg /usr/bin/cmg