## About GitHub Action to build and push Docker images. ___ * [Usage](#usage) * [Quick start](#quick-start) * [Bake](#bake) * [Git context](#git-context) * [Customizing](#customizing) * [inputs](#inputs) * [outputs](#outputs) * [Limitation](#limitation) ## Usage This action uses our [setup-buildx](https://github.com/docker/setup-buildx-action) action that extends the `docker build` command named [buildx](https://github.com/docker/buildx) with the full support of the features provided by [Moby BuildKit](https://github.com/moby/buildkit) builder toolkik. This includes multi-arch build, build-secrets, remote cache, etc. and different builder deployment/namespacing options. ### Quick start ```yaml 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 ``` ### Bake [Buildx bake](https://github.com/docker/buildx#buildx-bake-options-target) is also available with this action through the [`bake` inputs](#inputs): ```yaml name: ci on: pull_request: branches: master push: branches: master tags: jobs: bake: 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 }} push: true bake: true bake-files: | ./config.hcl bake-targets: | default release ``` ### Git context You can build from Git directly without [`actions/checkout`](https://github.com/actions/checkout/) action, even in private repositories if your `context` is a valid Git url: ```yaml 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 }} GIT_REF: ${{ github.ref }} with: context: ${{ github.repositoryUrl }} 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](https://github.com/docker/setup-buildx-action) 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](https://github.com/docker/buildx#--allowentitlement) (eg. `network.host,security.insecure`) | | `no-cache` | Bool | `false` | Do not use cache when building the image | | `platforms` | List | | List of [target platforms](https://github.com/docker/buildx#---platformvaluevalue) for build | | `load` | Bool | `false` | [Load](https://github.com/docker/buildx#--load) is a shorthand for `--output=type=docker` | | `push` | Bool | `false` | [Push](https://github.com/docker/buildx#--push) is a shorthand for `--output=type=registry` | | `outputs` | List | | List of [output destinations](https://github.com/docker/buildx#-o---outputpath-typetypekeyvalue) (format: `type=local,dest=path`) | | `cache-from` | List | | List of [external cache sources](https://github.com/docker/buildx#--cache-fromnametypetypekeyvalue) (eg. `user/app:cache`, `type=local,src=path/to/dir`) | | `cache-to` | List | | List of [cache export destinations](https://github.com/docker/buildx#--cache-tonametypetypekeyvalue) (eg. `user/app:cache`, `type=local,dest=path/to/dir`) | | `bake` | Bool | `false` | Use [bake](https://github.com/docker/buildx#buildx-bake-options-target) as the high-level build command | | `bake-files` | List | | List of [bake definition files](https://github.com/docker/buildx#file-definition) | | `bake-targets` | List | | List of bake targets | > List type can be a comma or newline-delimited string > ```yaml > tags: name/app:latest,name/app:1.0.0 > ``` > ```yaml > 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_HEADER`**¹** | Raw authorization header to authenticate against git repository | | `GIT_AUTH_TOKEN`**¹** | `x-access-token` basic auth to authenticate against git repository | | `GIT_REF`**¹** | Git refrerence to use against git repository | > **¹** Only used if `input.context` is a valid git uri. ## Limitation This action is only available for Linux [virtual environments](https://help.github.com/en/articles/virtual-environments-for-github-actions#supported-virtual-environments-and-hardware-resources).