Setting facts as environment variables

Another handy way to get information into Puppet and Facter is to pass it using environment variables. Any environment variable whose name starts with FACTER_ will be interpreted as a fact. For example, ask facter the value of hello using the following command:

[root@cookbook ~]# facter -p hello
Hello, world

Now override the value with an environment variable and ask again:

[root@cookbook ~]# FACTER_hello='Howdy!' facter -p hello
Howdy!

It works just as well with Puppet, so let's run through an example.

How to do it...

In this example we'll set a fact using an environment variable:

1. Keep the node definition for cookbook the same as our last example:

   node cookbook {
     notify {"$::hello": }
   }

2. Run the following command:

   [root@cookbook ~]# FACTER_hello="Hallo Welt" puppet agent -t
   Info: Caching catalog for cookbook.example.com
   Info: Applying configuration version '1416212026'
   Notice: Hallo Welt
   Notice: /Stage[main...