make docker build with version incrementor

Makefile

#!/usr/bin/env bash
.EXPORT_ALL_VARIABLES:
SHELL = /bin/bash
VENV_NAME = venv

PRODUCT = myapp

version=$(shell cat .version)

.PHONY: virtualenv
virtualenv:
	pip install virtualenv

.PHONY: docker_venv
docker_venv: virtualenv
	virtualenv --python $$(cat .python-version) ${VENV_NAME}
	@${VENV_NAME}/bin/pip install --upgrade pip
	@${VENV_NAME}/bin/pip install version_incrementor==1.5.0
	@echo "Installed version_incrementor"
	@touch ${VENV_NAME}/bin/activate
	@echo "virtualenv prepared, please run 'source ${VENV_NAME}/bin/activate' if you wish to use it in your current shell"

.PHONY: docker_authenticate_to_registry
docker_authenticate_to_registry:
	@docker login --username ${REGISTRY_USERNAME} --password "${REGISTRY_PASSWORD}" ${REGISTRY_FQDN}

.PHONY: docker_build 
docker_build: docker_venv
	@echo "Getting next version"
	@${VENV_NAME}/bin/prepare-release
	@docker build -t ${PRODUCT}:$$(cat .version) .