feat: add multiple stage build for docker.

.drone.yml

@@ -25,8 +25,6 @@ pipeline:
       - coverage all
       - make coverage
       - make build
-      # build binary for docker image
-      - make static_build
     when:
       event: [ push, tag, pull_request ]
 

Dockerfile

@@ -1,3 +1,7 @@
+FROM appleboy/golang-testing AS build-env
+ADD . /go/src/github.com/appleboy/drone-ssh
+RUN cd /go/src/github.com/appleboy/drone-ssh && make static_build
+
 FROM alpine:3.4
 
 RUN apk update && \
@@ -6,5 +10,5 @@ RUN apk update && \
     openssh-client && \
   rm -rf /var/cache/apk/*
 
-ADD drone-ssh /bin/
+COPY --from=build-env /go/src/github.com/appleboy/drone-ssh/drone-ssh /bin
 ENTRYPOINT ["/bin/drone-ssh"]