Cleanup Old Docker Images from Nexus Repository

Many of us are using Nexus as a repository to publish Docker images. Typically, we build images tagged with the commit hash (or using semver ideally) after SCM changes automatically in CI, and we push them to the registry. As a result, there are many "unneeded" and "old" images that, in our case, take up a significant amount of disk space.

I looked around the graphical interface of Nexus, and there's apparently nothing to remove several Docker images at the same time. Or even, a scheduled task to clean up old hosted Docker images — and to also clean up layers that are no longer used by any hosted images.

So I have come up with a simple bash script that uses the Docker Registry API to purge Docker images and keep the last X images and delete all others. But is there a better solution? YES! I built a Nexus CLI.

To install Nexus CLI, find the appropriate package for your system and download it. For Linux:

wget https://s3.eu-west-2.amazonaws.com/nexus-cli/1.0.0-beta/linux/nexus-cli

After downloading Nexus CLI. Add the execution permission to the binary:

chmod +x nexus-cli

Note: For Windows, make sure that the nexus-cli binary is available on the PATH. This page contains instructions for setting the PATH on Windows.

After installing, verify that the installation worked by opening a new terminal session and checking if nexus-cli is available:

Once done, configure the Nexus credentials:

nexus-cli configure

Through nexus-cli configure, the Nexus CLI will prompt you for four pieces of information. The Username and Password are your account credentials. You will also need your Nexus Hostname and Docker repository name.

That should be it. Try out the following command from your cmd prompt and, if you have any images, you should see them listed:

Display image tags:

nexus-cli image tags -name IMAGE_NAME

nexus-cli image info -name IMAGE_NAME -tag TAG

To remove a specific image:

nexus-cli image delete -name IMAGE_NAME -tag TAG

To keep only the last X images and delete all other:

nexus-cli image delete -name IMAGE_NAME -keep X

 That’s it! Let’s go back to Nexus Dashboard:

As you can see, Nexus kept only the last four images and deleted the others.

The CLI is still in its early stages, so you are welcome to contribute to the project on GitHub.

This article was originally published on labouardy.com