docker / build-push-action

Buildx Integration - docker/build-push-action

This document explains how to leverage Docker Buildx in the context of the Docker Build-Push Action project (https://github.com/docker/build-push-action/). We will cover the benefits of using Buildx, its configuration options, and how it facilitates multi-platform builds.

What is Docker Buildx?

Docker Buildx is a tool that allows you to build multi-platform Docker images more efficiently. It uses the Moby BuildKit backend and provides a unified API for build pipelines with consistent configuration and execution.

Benefits of using Buildx

  • Multi-platform image building: Buildx enables you to build images for multiple platforms (e.g., Linux, Windows, ARM) in a single command.
  • Improved performance: Buildx leverages the power of distributed builds, allowing you to distribute the build load across multiple machines.
  • Consistent configuration: Buildx provides a unified API for build pipelines, ensuring consistent configuration and execution.

Configuring Buildx in GitHub Actions

To use Buildx in GitHub Actions, you can utilize the docker/setup-buildx-action action. This action sets up Buildx on the GitHub Actions runner and optionally configures it with a specific version or BuildKit image.

Basic Configuration

To configure Buildx with the default settings, use the following code snippet:

- name: Set up Docker Buildx
uses: docker/setup-buildx-action@v3

Version Pinning

To pin the Buildx version to a specific release, use the version input:

- name: Set up Docker Buildx
uses: docker/setup-buildx-action@v3
with:
version: v0.10.0

Pinning BuildKit Image

To pin the BuildKit image to a specific version, use the image option in the driver-opts input:

- name: Set up Docker Buildx
uses: docker/setup-buildx-action@v3
with:
driver-opts:
image: moby/buildkit:0.11.0

Using a Dedicated BuildKit Config File

To use a dedicated BuildKit config file from your repository, use the config input:

- name: Set up Docker Buildx
uses: docker/setup-buildx-action@v3
with:
config: .github/buildkitd.toml

Multi-platform Builds

To perform multi-platform builds with Buildx, you can use the docker buildx build command with the --platform flag:

- name: Build and push multi-platform image
run: |
    docker buildx build \
      --tag your-username/multiarch-example:latest \
--platform linux/amd64,linux/arm/v7,linux/arm64 .

Environment Variables

Docker Buildx supports various environment variables that impact the behavior of building:

  • BUILDKIT_PROGRESS: Configure the type of progress output.
  • BUILDX_BUILDER: Override the configured builder instance.
  • BUILDX_CONFIG: Specify the location for configuration, state, and logs.

For a complete list of environment variables, refer to the official documentation.

Additional Resources