About

GitHub Action to build and push Docker images.

---

• Usage
  • Quick start
  • Git context
• Customizing
  • inputs
  • outputs
• Limitation

Usage

This action uses our setup-buildx action that extends the docker build command named buildx with the full support of the features provided by Moby BuildKit builder toolkik. This includes multi-arch build, build-secrets, remote cache, etc. and different builder deployment/namespacing options.

Quick start

name: ci

on:
  pull_request:
    branches: master
  push:
    branches: master
    tags:

jobs:
  buildx:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v2
      -
        name: Set up QEMU
        uses: docker/setup-qemu-action@v1
        with:
          platforms: all
      -
        name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v1
      -
        name: Login to DockerHub
        uses: crazy-max/ghaction-docker-login@v1 # switch to docker/login-action@v1 when available 
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}
      -
        name: Build and push
        uses: docker/build-push-action@v2
        with:
          builder: ${{ steps.buildx.outputs.name }}
          platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/386,linux/ppc64le,linux/s390x
          push: true
          tags: |
            user/app:latest
            user/app:1.0.0            

Git context

You can build from Git directly without actions/checkout action, even in private repositories if your context is a valid Git url:

name: ci

on:
  pull_request:
    branches: master
  push:
    branches: master
    tags:

jobs:
  git-context:
    runs-on: ubuntu-latest
    steps:
      -
        name: Set up QEMU
        uses: docker/setup-qemu-action@v1
        with:
          platforms: all
      -
        name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v1
        with:
          version: latest
      -
        name: Login to DockerHub
        uses: crazy-max/ghaction-docker-login@v1 # switch to docker/login-action@v1 when available
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}
      -
        name: Build and push
        uses: ./
        env:
          GIT_AUTH_TOKEN: ${{ github.token }}
        with:
          context: "${{ github.repositoryUrl }}#${{ github.ref }}"
          builder: ${{ steps.buildx.outputs.name }}
          platforms: linux/amd64,linux/arm64,linux/386
          push: true
          tags: |
            name/app:latest
            name/app:1.0.0            

Customizing

inputs

Following inputs can be used as step.with keys

Name	Type	Default	Description
builder	String		Builder instance (see setup-buildx action)
context	String	.	Build's context is the set of files located in the specified PATH or URL
file	String	./Dockerfile	Path to the Dockerfile.
build-args	List		List of build-time variables
labels	List		List of metadata for an image
tags	List		List of tags
pull	Bool	false	Always attempt to pull a newer version of the image
target	String		Sets the target stage to build
allow	List		List of extra privileged entitlement (eg. network.host,security.insecure)
no-cache	Bool	false	Do not use cache when building the image
platforms	List		List of target platforms for build
load	Bool	false	Load is a shorthand for --output=type=docker
push	Bool	false	Push is a shorthand for --output=type=registry
outputs	List		List of output destinations (format: type=local,dest=path)
cache-from	List		List of external cache sources (eg. user/app:cache, type=local,src=path/to/dir)
cache-to	List		List of cache export destinations (eg. user/app:cache, type=local,dest=path/to/dir)

List type can be a comma or newline-delimited string

tags: name/app:latest,name/app:1.0.0

tags: |
  name/app:latest
  name/app:1.0.0  

outputs

Following outputs are available

Name	Type	Description
digest	String	Image content-addressable identifier also called a digest

environment variables

Following environment variables can be used as step.env keys

Name	Description
GIT_AUTH_HEADER¹	Raw authorization header to authenticate against git repository
GIT_AUTH_TOKEN¹	x-access-token basic auth to authenticate against git repository

¹ Only used if input.context is a valid git uri.

Limitation

This action is only available for Linux virtual environments.