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:
      -
        # Add support for more platforms with QEMU (optional)
        # https://github.com/docker/setup-qemu-action
        name: Set up QEMU
        uses: docker/setup-qemu-action@v4
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4

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)
name	String		Name of the builder. If not specified, one will be generated or if it already exists, it will be used instead of creating a new one
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
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
keep-state	Bool	false	Keep BuildKit state on cleanup. This is only useful on persistent self-hosted runners
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	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

Example:

[
  {
    "name": "builder-8fa135e1-9bce-4a29-9368-46a09a1d750d0",
    "endpoint": "unix:///var/run/docker.sock",
    "status": "running",
    "buildkitd-flags": "--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host",
    "buildkit": "v0.27.1",
    "platforms": "linux/amd64,linux/amd64/v2,linux/amd64/v3,linux/386"
  }
]

Contributing

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