Undocumented Features: Salt Runner Silence

Salt Project is a useful tool for DevOps. It has functionality for days (as the kids say), and Runner modules stand out as powerful utilities that allow for the execution of tasks directly on the master. Runners are typically executed from the command line using the salt-run command, with their output displayed in stdout. However, a deeper exploration into the Salt Project’s code base reveals an undocumented feature that adds a layer of flexibility and security to the execution of Runner modules.

Unveiling the undocumented feature

Runner modules, while traditionally executed directly on the master, can also be triggered by publishing an event on a minion through the publish.runner execution module. While this method offers a different approach to executing Runner modules, it also raises a concern: the potential exposure of sensitive output information in the journalctl logs. This alternative execution method may end up redirecting the output from stdout to the journalctl logs on the master depending on the service configuration.

Addressing this concern is an undocumented configuration parameter: quiet. Found within the code, this hidden gem allows for enhanced control over the output of the Runner modules. By setting quiet: true in the master configuration, the output from the execution of Runner modules is suppressed, preventing it from being displayed in the journalctl logs. This helps in maintaining the confidentiality of sensitive information which may be otherwise exposed by a Runner module.

The way forward: enhanced documentation

It’s somewhat disconcerting to stumble upon an undocumented feature like the quiet configuration parameter in the Salt Project’s code base. When it comes to Salt for DevOps, users and administrators rely on comprehensive documentation to fully utilize the platform’s capabilities and ensure secure and efficient operations. Discovering features through a meticulous code base exploration, rather than straightforward documentation, is far from ideal. However, this discovery provides an opportunity for improvement. Ensuring that features, especially those pertinent to security and operational efficiency, are well-documented and easily accessible, is imperative. We’ll be working on documenting and/or creating a better workflow for this behavior, enhancing the user experience and the overall functionality of the Salt Project. At EITR, we love Open Source!