Contributing to Rockstor Rock-ons

Rock-ons are Docker plugins (see Rock-ons (Docker Plugins) for more information) defined by a JSON file stored in the rockon-registry repository on As detailed in the Adding your own Rock-on section, please refer to rockon-registry for full instructions and examples on how to write your own Rock-on definition file.

If you are interested in donating a Rock-on for your favorite project, please consider contributing to the rockon-registry by submitting a pull-request. Steps for doing so are similar to those required for Contributing to Rockstor - Overview or Contributing to Rockstor documentation. Briefly, these would consist in:

  1. Creating an issue in the rockon-registry repository.
  2. Creating your own fork of the rockon-registry.
  3. Create a new branch dedicated to the issue you just created (ideally containing the issue #).
  4. Write your Rock-on JSON definition file following the as guideline.
  5. Once you’re finished writing and testing your new Rock-on definition file, upload it to this branch.
  6. Submit a pull-request to the rockon-registry repository.

Which Docker image should I use?

Docker hub centralizes a very large number of docker images. As a result, it can sometimes be difficult to select the best image among dozens for very popular projects. While it is nearly impossible to provide a simple “rule” for selecting the best image, the best image for a Rock-on will be secure, maintained in the long-term, compatible with Rockstor, and allow for “all-in-one” use for the end-user. In this context, the following guidelines can help:

  • Is there an official image for your project of interest? Official images are clearly labeled in Docker hub and provide assurance with regards to security, and long-term maintenance of the image.
  • Does the project provide its own docker image? These usually ensure the good quality of the image and best experience with the respective project.
  • Is the image regulary updated? Generally, an image with active maintainer(s) and community will be able to offer better support and timely updates. The image history on its Docker hub page as well as the number of pulls/favorites can be a useful indicator of an active image.
  • Does the image allow for an “all-in-one” user experience? Ideally, the image would allow for an easy install from the Rockstor’s webUI without requiring user intervention at the command line before and/or after.
  • Finally, the image size is another helpful factor, with smaller images being usually favored.