.PHONY: tag push clean container
default: push

IMAGE=node_exporter
SHA_IMAGE=alpine:3.5@sha256:dfbd4a3a8ebca874ebd2474f044a0b33600d4523d03b0df76e5c5986cb02d7e8

container: Dockerfile
	docker build --no-cache -t $(IMAGE):build .

hash: Dockerfile
	find $^ -type f | xargs cat | docker run --rm -i $(SHA_IMAGE) sha1sum - | sed 's/ .*//' > hash

push: hash container
	docker pull linuxkit/$(IMAGE):$(shell cat hash) || \
		(docker tag $(IMAGE):build linuxkit/$(IMAGE):$(shell cat hash) && \
		 docker push linuxkit/$(IMAGE):$(shell cat hash))
	docker rmi $(IMAGE):build
	rm -f hash

tag: hash container
	docker pull linuxkit/$(IMAGE):$(shell cat hash) || \
		docker tag $(IMAGE):build linuxkit/$(IMAGE):$(shell cat hash)
	docker rmi $(IMAGE):build
	rm -f hash

clean:
	rm -rf hash

.DELETE_ON_ERROR: