The Chef client uses a tool called Ohai to gather data about a node. For example, by default, Ohai collects a node's platform, platform version, and IP address. The data Ohai collects is stored on the Chef server and can be used for reporting, troubleshooting, and in your recipes. However, Ohai's real power lies in its plugin interface. You can build custom Ohai plugins that help you to create dynamic recipes and that supplement the information you collect about a node.
In this webinar, we explain Ohai's plugin structure, walk through the core Ohai plugins, and show you how to build and test a custom plugin. Finally, we talk about some further refinements you can add to the implementation.