2 years ago

Category: Software

When you write enough Puppet code, you will eventually find yourself in need of a Facter fact or Puppet resource type that doesn’t exist in Puppet itself. However, sometimes your search turns up blank and you are confronted with a choice: abandon what you are trying to do, or; write a new custom fact or a new custom type / provider.

The catch is that the custom fact and the custom type / provider will need AwesomeApp dependencies installed on the node, and not every node will have AwesomeApp installed on it.

Here’s what confinement looks like in the code of a custom Facter fact (it looks nearly identical in custom type / provider code as well): Confining a custom Facter fact or custom type / provider involves using the confine function to, typically, only allow resolution of the fact on nodes that can satisfy the parameters you have given it.

You could bake the check into the custom fact and custom type / provider code itself, but that would introduce a lot of conditional statements and make your new code more error-prone.