Change image layering - plugin builds on weaver & weaver builds on weaveexec

Makefile

@@ -131,8 +131,8 @@ $(BUILD_UPTODATE): build/*
 %/Dockerfile.$(DOCKERHUB_USER): %/Dockerfile.template
 	sed -e "s/DOCKERHUB_USER/$(DOCKERHUB_USER)/" $^ > $@
 
-$(WEAVER_UPTODATE): prog/weaver/Dockerfile $(WEAVER_EXE)
-	$(SUDO) DOCKER_HOST=$(DOCKER_HOST) docker build -t $(WEAVER_IMAGE) prog/weaver
+$(WEAVER_UPTODATE): prog/weaver/Dockerfile.$(DOCKERHUB_USER) $(WEAVER_EXE) $(WEAVEEXEC_UPTODATE)
+	$(SUDO) DOCKER_HOST=$(DOCKER_HOST) docker build -f prog/weaver/Dockerfile.$(DOCKERHUB_USER) -t $(WEAVER_IMAGE) prog/weaver
 	touch $@
 
 $(WEAVEEXEC_UPTODATE): prog/weaveexec/Dockerfile prog/weaveexec/symlink $(DOCKER_DISTRIB) weave $(SIGPROXY_EXE) $(WEAVEPROXY_EXE) $(WEAVEWAIT_EXE) $(WEAVEWAIT_NOOP_EXE) $(WEAVEWAIT_NOMCAST_EXE) $(WEAVEUTIL_EXE)
@@ -147,7 +147,7 @@ $(WEAVEEXEC_UPTODATE): prog/weaveexec/Dockerfile prog/weaveexec/symlink $(DOCKER
 	$(SUDO) DOCKER_HOST=$(DOCKER_HOST) docker build -t $(WEAVEEXEC_IMAGE) prog/weaveexec
 	touch $@
 
-$(PLUGIN_UPTODATE): prog/plugin/Dockerfile.$(DOCKERHUB_USER) $(PLUGIN_EXE) $(WEAVEEXEC_UPTODATE)
+$(PLUGIN_UPTODATE): prog/plugin/Dockerfile.$(DOCKERHUB_USER) $(PLUGIN_EXE) $(WEAVER_UPTODATE)
 	$(SUDO) docker build -f prog/plugin/Dockerfile.$(DOCKERHUB_USER) -t $(PLUGIN_IMAGE) prog/plugin
 	touch $@
 

prog/plugin/Dockerfile.template

@@ -1,3 +1,3 @@
-FROM DOCKERHUB_USER/weaveexec
+FROM DOCKERHUB_USER/weave
 ADD ./plugin /home/weave/
 ENTRYPOINT ["/home/weave/plugin"]

prog/weaver/Dockerfile.template

@@ -1,4 +1,4 @@
-FROM scratch
+FROM DOCKERHUB_USER/weaveexec
 MAINTAINER Weaveworks Inc <help@weave.works>
 LABEL works.weave.role=system
 WORKDIR /home/weave