Using search to find nodes

If you are running your infrastructure in any type of virtualized environment, such as a public or private cloud, the server instances that you use will change frequently. Instead of having a well-known set of servers, you destroy and create virtual servers regularly.

In this situation, your cookbooks cannot rely on hardcoded server names when you need a list of available servers.

Chef provides a way to find nodes by their attributes, for example, their roles. In this section, we'll see how you can retrieve a set of nodes to use them in your recipes.

Getting ready

Make sure that you have a cookbook called my_cookbook, as described in the Creating and using cookbooks section in Chapter 1, Chef Infrastructure.

How to do it...

Let's see how we can find all nodes having a certain role:

1. Create a role called web that has my_cookbook in its run list. This command will open a JSON definition of your role in your default editor. You need to add "recipe[my_cookbook]" to "run_list...