Chainguard Container for sftp

Various scripts from https://github.com/atmoz/sftp to help run SFTP in a container

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/sftp:latest

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

Compatibility Notes

Chainguard's Atmoz SFTP image is comparable to the official Atmoz SFTP image. The upstream image includes the openssh-server-pam package in their image, , but we found it unnecessary for our version. None of the settings in upstream’s sshd_config require PAM, and user authentication relies solely on the shadow file.

Getting Started

Ensure you have OpenSSH installed, specifically the openssh-client package, which includes the sftp command.

Replace <host-dir> with your desired directory and run:

docker run --rm --name sftp-container -v <host-dir>/upload:/home/foo/upload -p 2222:22 -it cgr.dev/ORGANIZATION/atmoz-sftp:latest foo:pass:::upload

You can verify the container is running with a docker ps command:

docker ps | grep sftp-container

To check if Wildfly has started successfully, check the logs with docker logs:

docker logs sftp-container | grep "Server listening on :: port 22."

Create a test file in your upload directory:

echo "test file" > <host-dir>/upload

Connect to the SFTP server:

sftp -o StrictHostKeyChecking=no -P 2222 foo@127.0.0.1

Enter the password (pass) when prompted. Once inside the SFTP shell, upload and verify the file:

put <host-dir>/upload/test.txt upload/test.txt
ls upload/test.txt
exit

Confirm the file is inside the container:

docker exec -it sftp-container ls -l /home/foo/upload | grep test.txt

Stop the container when done:

docker stop sftp-container

Documentation and Resources

• Atmoz SFTP

What are Chainguard Containers?

Chainguard Containers are minimal container images that are secure by default.

In many cases, the Chainguard Containers tagged as :latest contain only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager. Chainguard Containers are built with Wolfi, our Linux undistro 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 -dev variant.

Although the -dev container image variants have similar security features as their more minimal versions, they feature additional software that is typically not necessary in production environments. We recommend using multi-stage builds to leverage the -dev variants, copying application artifacts into a final minimal container that offers a reduced attack surface that won’t allow package installations or logins.

Learn More

To better understand how to work with Chainguard Containers, please visit Chainguard Academy and Chainguard Courses.

In addition to Containers, Chainguard offers VMs and Libraries. Contact Chainguard to access additional products.

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.