Switching options on and off in a configuration file is a pretty common thing. Since Chef is using ERB as its template language, you can use pure Ruby to control the flow in your templates. You can use conditionals or even loops in your templates.
Make sure you have a cookbook called
my_cookbook and the
run_list of your node includes
my_cookbook as described in the Creating and using cookbooks section in Chapter 1, Chef Infrastructure.
Let's create a hypothetical configuration file listing the IP addresses of a given set of backend servers. We only want to print that list if the flag called
enabled is set to