buildkite-agent

packaged by Chainguard

Chainguard Container for buildkite-agent

Buildkite Agent is a CI/CD build runner that polls Buildkite for work, runs build jobs, and reports results

Chainguard Containers are regularly-updated, secure-by-default container images.

Download this Container Image

For those with access, this container image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/buildkite-agent:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

Compatibility Notes

This image is compatible with the upstream buildkite/agent:latest image.

Why this image runs as root

This image runs as root (uid 0), matching the upstream buildkite/agent image.

The upstream team attempted nonroot execution but abandoned it. The agent needs root to access the Docker socket (/var/run/docker.sock), clean up root-owned files left behind by Docker container builds, and write to ~/.ssh/known_hosts during git checkout.

The upstream team is considering nonroot support but has not yet implemented it.

From the maintainer:

It's certainly something we'd consider, it just makes orchestration a lot more complicated, especially for docker with user namespacing enabled.

See also: Buildkite Docker security considerations, Buildkite blog on build permissions.

Getting Started

Prerequisites

1. A Buildkite account
2. An agent token from Buildkite > Agents > Agent Tokens > New Token

Running the Agent

To start a Buildkite Agent connected to your Buildkite organization:

docker run --rm \
  -e BUILDKITE_AGENT_TOKEN="<your-token>" \
  cgr.dev/ORGANIZATION/buildkite-agent:latest

On successful connection, you should see output similar to:

Starting buildkite-agent ...
Successfully registered agent "<container-id>" with tags [queue=default]
Connecting to Buildkite...
Waiting for instructions...

Using a Custom Configuration File

The agent reads its configuration from /buildkite/buildkite-agent.cfg by default. You can mount a custom configuration file:

docker run --rm \
  -e BUILDKITE_AGENT_TOKEN="<your-token>" \
  -v /path/to/buildkite-agent.cfg:/buildkite/buildkite-agent.cfg \
  cgr.dev/ORGANIZATION/buildkite-agent:latest

Deploying with Helm

The image can be deployed using the upstream Buildkite Helm chart:

helm repo add buildkite https://buildkite.github.io/charts
helm repo update buildkite

helm install buildkite-agent buildkite/agent \
  --set image.repository=cgr.dev/ORGANIZATION/buildkite-agent \
  --set image.tag=latest \
  --set agent.token="<your-token>" \
  --namespace buildkite --create-namespace

Verify the agent is running:

kubectl --namespace=buildkite get pods -l "app=agent,release=buildkite-agent"
kubectl --namespace=buildkite logs -l "app=agent,release=buildkite-agent"

Documentation and Resources

• Buildkite Agent Documentation
• Buildkite Agent GitHub Repository
• Buildkite Pipelines Documentation
• Buildkite Helm Chart

What are Chainguard Containers?

Chainguard's free tier of Starter container images are built with Wolfi, our minimal Linux undistro.

All other Chainguard Containers are built with Chainguard OS, Chainguard's minimal Linux operating system designed to produce container images that meet the requirements of a more secure software supply chain.

The main features of Chainguard Containers include:

• Minimal design, without unnecessary software bloat
• Daily builds to ensure container images are up-to-date with available security patches
• High quality build-time SBOMs attesting to the provenance of all artifacts within the image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

For cases where you need container images with shells and package managers to build or debug, most Chainguard Containers come paired with a development, or -dev, variant.

In all other cases, including Chainguard Containers tagged as :latest or with a specific version number, the container images include only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager.

Although the -dev container image variants have similar security features as their more minimal versions, they include additional software that is typically not necessary in production environments. We recommend using multi-stage builds to copy artifacts from the -dev variant into a more minimal production image.

Need additional packages?

To improve security, Chainguard Containers include only essential dependencies. Need more packages? Chainguard customers can use Custom Assembly to add packages, either through the Console, chainctl, or API.

To use Custom Assembly in the Chainguard Console: navigate to the image you'd like to customize in your Organization's list of images, and click on the Customize image button at the top of the page.

Learn More

Refer to our Chainguard Containers documentation on Chainguard Academy. Chainguard also offers VMs and Libraries — contact us for access.

Trademarks

This software listing is packaged by Chainguard. The trademarks set forth in this offering are owned by their respective companies, and use of them does not imply any affiliation, sponsorship, or endorsement by such companies.