Docker build, tag and push helper script

Makefile

# Docker build helper

-include .make

REPO 		:= $(shell grep REPO .make 2>/dev/null | cut -d '=' -f2)
IMAGE 		:= $(shell grep IMAGE .make 2>/dev/null | cut -d '=' -f2)
VERSION		:= $(shell grep VERSION .make 2>/dev/null | cut -d '=' -f2)

TIMESTAMP 	:= $(shell date +%Y.%m.%d-%H.%M.%S)

TAG 		:= $(REPO)/$(IMAGE):$(VERSION)-$(TIMESTAMP)
LATEST		:= $(REPO)/$(IMAGE):latest


.PHONY: help
help:
	@echo "Please use 'make <target>' where <target> is one of the following:"
	@echo "	help         to print this help (the default)"
	@echo "	build        to build a docker image with semantic version and timestamp"
	@echo "	push         to push the latest image and semantic versioned image timestamp"
	@echo "	prune        to prune all tagged $(IMAGE) images"
	@echo "	test         to print an example of genetared image names"
	@echo "	init         to generate a .make file with placeholders for the REPO, IMAGE, and VERSION variables"
	@echo $(REPO) $(IMAGE) $(VERSION)


.PHONY: build
build: check_makefile
	@echo "Building your images..."
	docker build --build-arg PB_VERSION=$(VERSION) . -t $(TAG)
	docker tag $(TAG) $(LATEST)


.PHONY: push
push: check_makefile
	@echo "Pushing your images..."
	docker login
	docker push $(TAG)
	docker push $(LATEST)


.PHONY: test
test: check_makefile
	@echo "Example of names generated:"
	@echo	"	$(TAG)"
	@echo	"	$(LATEST)"


.PHONY: prune
prune: check_makefile
	@echo "Pruning images prefixed with $(REPO)/$(IMAGE)..."
	@docker images --filter "reference=$(REPO)/$(IMAGE)*" -q | xargs -r docker rmi -f


.PHONY: init
init:
	@echo "Generating .make file..."
	@echo "REPO=\nIMAGE=\nVERSION=" > .make


# checkings TODO check .make exist and variables are not empty

check_makefile: