Chainguard Container for REPO_NAME

A fast TCP/UDP tunnel over HTTP

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/REPO_NAME:latest

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

What is Chisel?

Chisel is a fast TCP/UDP tunnel, transported over HTTP, secured via SSH. It allows you to create secure tunnels through firewalls and NAT devices. This container image provides both server and client functionality for creating encrypted tunnels.

Usage

The chisel container can be run in two modes: server and client.

Server Mode

Start a chisel server with authentication:

docker run -p 8080:8080 --name chisel-server -d \
  cgr.dev/$ORGANIZATION/chisel server --auth username:password

Start a server without authentication (not recommended for production):

docker run -p 8080:8080 --name chisel-server -d \
  cgr.dev/$ORGANIZATION/chisel server

Client Mode

Connect to a chisel server and create a tunnel:

docker run -p 28080:28080 --name chisel-client -d \
  cgr.dev/$ORGANIZATION/chisel client --auth username:password \
  http://server-host:8080 28080:target-host:80

Complete Example

Here's a complete example that demonstrates setting up a tunnel to access an nginx server:

1. Create a Docker network:

docker network create chisel-test

2. Start an nginx server:

docker run --network chisel-test -p 18080:8080 --name nginx -d \
  cgr.dev/$ORGANIZATION/nginx

3. Start the chisel server:

docker run --network chisel-test -p 8080:8080 --name chisel-server -d \
  cgr.dev/$ORGANIZATION/chisel server --auth testuser:S3cr3tP@ssword

4. Start the chisel client to create a tunnel:

docker run --network chisel-test -p 28080:28080 --name chisel-client -d \
  cgr.dev/$ORGANIZATION/chisel client --auth testuser:S3cr3tP@ssword \
  http://chisel-server:8080 28080:nginx:8080

5. Test the tunnel:

# Access nginx directly
curl http://localhost:18080

# Access nginx through the chisel tunnel
curl http://localhost:28080

Common Use Cases

• Bypassing firewalls: Create tunnels through restrictive network environments
• Accessing internal services: Expose internal services through a single HTTP endpoint
• Reverse tunnels: Allow external access to services behind NAT
• Port forwarding: Forward local ports to remote services

Security Notes

• Always use authentication (--auth username:password) in production environments
• Consider using TLS/HTTPS for the transport layer when possible
• Regularly rotate authentication credentials
• Monitor tunnel usage and connections

Troubleshooting

Check server logs:

docker logs chisel-server

Check client logs:

docker logs chisel-client

The server should show "Listening on" and the client should show "Connected" when the tunnel is established successfully.

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.