Build binary in a docker container

So that people don't need to install all dependencies just to build.

Make it so that "make binary" does nothing if nothing changed.

Remove ${DEST}

Signed-off-by: Doug Davis <dug@us.ibm.com>

Dockerfile.build

@@ -0,0 +1,5 @@
+FROM ubuntu:16.04
+RUN apt-get update
+RUN apt-get install -y golang git-core libgpgme11-dev
+ENV GOPATH=/
+WORKDIR /src/github.com/projectatomic/skopeo

Makefile

@@ -25,8 +25,18 @@ GIT_COMMIT := $(shell git rev-parse HEAD 2> /dev/null || true)
 
 all: binary
 
-binary:
-	go build -ldflags "-X main.gitCommit=${GIT_COMMIT}" -o ${DEST}skopeo ./cmd/skopeo
+binary: skopeo
+
+# Build a docker image (skopeobuild) that has everything we need to build.
+# Then do the build and the output (skopeo) should appear in current dir
+skopeo: cmd/skopeo
+	docker build ${DOCKER_BUILD_ARGS} -f Dockerfile.build -t skopeobuildimage .
+	docker run --rm -v ${PWD}:/src/github.com/projectatomic/skopeo \
+		skopeobuildimage make binary-local
+
+# Build w/o using Docker containers
+binary-local:
+	go build -ldflags "-X main.gitCommit=${GIT_COMMIT}" -o skopeo ./cmd/skopeo
 
 build-container:
 	docker build ${DOCKER_BUILD_ARGS} -t "$(DOCKER_IMAGE)" .

hack/make/test-integration

@@ -8,7 +8,7 @@ bundle_test_integration() {
 
 # subshell so that we can export PATH without breaking other things
 (
-	make binary
+	make binary-local
 	make install-binary
 	export GO15VENDOREXPERIMENT=1
 	bundle_test_integration