GitHub Actions to build and push a Docker image to GitHub Packages Registry

build.yml

name: Build and push the Docker image

on:
  push:
    paths:
      - docker/**

jobs:
  build:
    runs-on: ubuntu-18.04
    steps:
      - uses: actions/checkout@v2
      - run: make -C docker release
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        #if: github.event.push.ref == 'refs/heads/master'

Dockerfile

FROM alpine:3.11
ARG VERSION
#TODO: add steps

Makefile

VERSION := v1.0.0

IMAGE_NAME := docker.pkg.github.com/octocat/example/example
IMAGE_TAG := $(VERSION)
GITHUB_USERNAME := octocat

.PHONE: build
build: Dockerfile
	docker pull $(IMAGE_NAME):$(IMAGE_TAG)
	docker build -t $(IMAGE_NAME):$(IMAGE_TAG) --build-arg VERSION=$(VERSION) .
	docker run --rm $(IMAGE_NAME):$(IMAGE_TAG) --version

.PHONE: release
release: build
	docker login docker.pkg.github.com --username $(GITHUB_USERNAME) --password $(GITHUB_TOKEN)
	docker push $(IMAGE_NAME):$(IMAGE_TAG)

.PHONY: clean
clean:
	docker rmi $(IMAGE_NAME):$(IMAGE_TAG)