Revert "release: skip downloading go modules in container image builds (#821)"

This reverts commit ba0891b7b7.

Dockerfile

@@ -1,3 +1,12 @@
+FROM golang:1.12.4-alpine3.9 as builder
+
+RUN apk add --no-cache make git
+WORKDIR /workspace/helmfile
+COPY . /workspace/helmfile
+RUN make static-linux
+
+# -----------------------------------------------------------------------------
+
 FROM alpine:3.8
 
 RUN apk add --no-cache ca-certificates git bash curl jq
@@ -27,6 +36,6 @@ RUN helm plugin install https://github.com/databus23/helm-diff && \
     helm plugin install https://github.com/hypnoglow/helm-s3.git && \
     helm plugin install https://github.com/aslafy-z/helm-git.git
 
-COPY dist/helmfile_linux_amd64 /usr/local/bin/helmfile
+COPY --from=builder /workspace/helmfile/dist/helmfile_linux_amd64 /usr/local/bin/helmfile
 
 CMD ["/usr/local/bin/helmfile"]

Makefile

@@ -26,7 +26,7 @@ integration:
 .PHONY: integration
 
 cross:
-	env CGO_ENABLED=0 gox -os '!openbsd !freebsd !netbsd' -arch '!arm !mips !mipsle !mips64 !mips64le !s390x' -output "dist/{{.Dir}}_{{.OS}}_{{.Arch}}" -ldflags '-X main.Version=${TAG}' ${TARGETS}
+	env CGO_ENABLED=0 gox -os '!openbsd !freebsd !netbsd' -arch '!arm !mips !mipsle !mips64 !mips64le' -output "dist/{{.Dir}}_{{.OS}}_{{.Arch}}" -ldflags '-X main.Version=${TAG}' ${TARGETS}
 .PHONY: cross
 
 static-linux:
@@ -50,13 +50,9 @@ release: pristine cross
 	@ghr -b ${BODY} -t ${GITHUB_TOKEN} -u ${ORG} -recreate ${TAG} dist
 .PHONY: release
 
-image: static-linux/in-docker
+image:
 	docker build -t quay.io/${ORG}/helmfile:${TAG} .
 
-static-linux/in-docker:
-	if [ -f dist/helmfile_linux_amd64 ]; then echo removing dist/helmfile_linux_amd64; rm dist/helmfile_linux_amd64; fi
-	docker run -v $(HOME)/go:/go -v $(PWD):/workspace/helmfile -w /workspace/helmfile golang:1.12.4-alpine3.9 sh -c 'apk add --no-cache make git && make static-linux'
-
 run: image
 	docker run --rm -it -t quay.io/${ORG}/helmfile:${TAG} sh