So far, we have seen the different components of Chef and we have also seen what is possible by making use of the Chef server API. The Chef ecosystem is built for use by operations people and developers alike, and it comes with a bunch of tools such as Ohai, Knife, and so on, which can be used to manage your infrastructure easily using Chef.

However, every now and then you'll find that the available tools just aren't good enough to meet your requirements and this is the time when you can utilize the knowledge that you gathered about the API and internals of Ohai and Knife, and extend the Chef ecosystem by developing your very own resource providers, Ohai plugins, Knife plugins, or an all together different tool set using Chef API meshed up with other APIs.

We have already seen how to write our own custom resource provider and Ohai plugin in the previous chapters. In this chapter, we'll learn how to go about building custom Knife plugins and we'll also see how we...