About

GitHub Action to set up Docker Buildx.

This action will create and boot a builder that can be used in the following steps of your workflow if you're using Buildx or the build-push action. By default, the docker-container driver will be used to be able to build multi-platform images and export cache using a BuildKit container.

---

• Usage
• Configuring your builder
• Customizing
  • inputs
  • outputs
  • environment variables
• Notes
  • nodes output
• Contributing

Usage

name: ci

on:
  push:

jobs:
  buildx:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        # Add support for more platforms with QEMU (optional)
        # https://github.com/docker/setup-qemu-action
        name: Set up QEMU
        uses: docker/setup-qemu-action@v3
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

Configuring your builder

• Version pinning: Pin to a specific Buildx or BuildKit version
• BuildKit container logs: Enable BuildKit container logs for debugging purposes
• BuildKit Daemon configuration
  • Registry mirror: Configure a registry mirror for your builds
  • Max parallelism: Configure the maximum parallelism for your builds
• Append additional nodes to the builder: Create additional nodes for your builder
• Authentication for remote builders
  • SSH authentication: Authenticate to a remote builder using SSH
  • TLS authentication: Authenticate to a remote builder using TLS
• Standalone mode: Use Buildx as a standalone binary (without the Docker CLI)
• Isolated builders: Create isolated builders for your builds

Customizing

inputs

The following inputs can be used as step.with keys:

List type is a newline-delimited string

driver-opts: |
  image=moby/buildkit:master
  network=host

CSV type must be a comma-delimited string

platforms: linux/amd64,linux/arm64

Name	Type	Default	Description
version	String		Buildx version. (eg. v0.3.0, latest, https://github.com/docker/buildx.git#master)
driver	String	docker-container	Sets the builder driver to be used
driver-opts	List		List of additional driver-specific options (eg. image=moby/buildkit:master)
buildkitd-flags	String		BuildKit daemon flags
buildkitd-config *	String		BuildKit daemon config file
buildkitd-config-inline *	String		Same as buildkitd-config but inline
install	Bool	false	Sets up docker build command as an alias to docker buildx
use	Bool	true	Switch to this builder instance
endpoint	String		Optional address for docker socket or context from docker context ls
platforms	List/CSV		Fixed platforms for current node. If not empty, values take priority over the detected ones.
append	YAML		Append additional nodes to the builder
cache-binary	Bool	true	Cache buildx binary to GitHub Actions cache backend
cleanup	Bool	true	Cleanup temp files and remove builder at the end of a job

Important

If you set the buildkitd-flags input, the default flags (--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host) will be reset. If you want to retain the default behavior, make sure to include these flags in your custom buildkitd-flags value.

Note

buildkitd-config and buildkitd-config-inline are mutually exclusive.

outputs

The following outputs are available:

Name	Type	Description
name	String	Builder name
driver	String	Builder driver
platforms	String	Builder node platforms (preferred and/or available)
nodes	JSON	Builder nodes metadata

environment variables

The following official docker environment variables are supported:

Name	Type	Default	Description
DOCKER_CONFIG	String	~/.docker	The location of your client configuration files

Notes

nodes output

[
  {
     "name": "builder-3820d274-502c-4498-ae24-d4c32b3023d90",
     "endpoint": "unix:///var/run/docker.sock",
     "driver-opts": [
       "network=host",
       "image=moby/buildkit:master"
     ],
    "status": "running",
    "buildkitd-flags": "--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host",
    "buildkit": "3fab389",
    "platforms": "linux/amd64,linux/amd64/v2,linux/amd64/v3,linux/amd64/v4,linux/386"
  }
]

Name	Type	Description
name	String	Node name
endpoint	String	Node endpoint
driver-opts	List	Options for the driver
status	String	Node status
buildkitd-flags	String	Flags for buildkitd daemon
buildkit	String	BuildKit version
platforms	String	Platforms available

Contributing

Want to contribute? Awesome! You can find information about contributing to this project in the CONTRIBUTING.md