An example Makefile for Docker and Leiningen.

Makefile

.PHONY: build test deploy

##-- Environment Variables --#

# Image and container registry
IMAGE_NAME := my-image-name
IMAGE_PATH := mygroup/myproject
REGISTRY   := registry-url:port
IMAGE      := $(REGISTRY)/$(IMAGE_PATH)/$(IMAGE_NAME)

# Get current branch and transform '/' to '-'
BRANCH := $(or $(CI_COMMIT_REF_NAME), `git rev-parse --abbrev-ref HEAD`)
BRANCH := $(shell echo $(BRANCH) | tr / -)

# Retrieve first 7 characters of current commit hash
SHORT_HASH := `git rev-parse --short HEAD`

# Docker image tag for a local build
BUILD_TAG := $(IMAGE):build

# Docker image tag that will be pushed to the registry
TAG := $(IMAGE):$(BRANCH)-$(SHORT_HASH)

##-- Main Makefile Targets --##

# build - build a local docker image and tag the image
build: docker-build docker-tag

# test - run unit tests
test:
	lein test

# deploy - push image into registry
deploy: docker-login docker-push

##-- Extra Makefile Targets --##

# clean - cleanup project space
clean:
	lein clean

# docs - build documentation
docs:
	lein codox

# shell - open a shell on the build container
shell:
	docker run --interactive --tty --rm --name testing $(BUILD_TAG) /bin/bash

##-- Lein Targets --##

# build-lein - build the project uberjar
lein-build:
	lein deps
	lein uberjar

# deploy-lein - deploy the project to clojars
deploy-lein: lein-build test
	lein deploy clojars

##-- Docker Helper Targets --##

# docker-build - build an image with a local build tag
docker-build:
	docker build --tag $(BUILD_TAG) --rm --compress $(PWD)

# docker-tag - prep local built image with tag for pushing to registry
docker-tag:
	docker tag $(BUILD_TAG) $(TAG)

# docker-login - login to registry using vars if available,
#                otherwise interactive login.
docker-login:
        @$(if $(and $(CI_REGISTRY_USER), $(CI_REGISTRY_PASSWORD)), \
                docker login -u $(CI_REGISTRY_USER) \
                        -p $(CI_REGISTRY_PASSWORD) \
                        $(CI_REGISTRY), \
       docker login $(REGISTRY))

# docker-push - push image to registry
docker-push:
	docker push $(TAG)

##-- Debug --##

# debug - display all environment variables
debug:
	@echo "IMAGE:     $(IMAGE)"
	@echo "BUILD_TAG: $(BUILD_TAG)"
	@echo "TAG:       $(TAG)"