Override or disable built-in facts in Puppet Enterprise

When Facter’s built-in facts cause issues with third-party software or Puppet Enterprise (PE), you might want to override or disable them.

For example:

• The ec2 structured fact might cause repeated connections to Openstack metadata nodes.

• A very large fact might cause performance issues, such as slow Puppet runs.

• Solaris automounts each user’s home directory, causing the mountpoints fact, which stores all filesystems mounted on each system, to become very large.

Version and installation information

PE version: All supported

Solution

In PE 2021.0 and later, you can block any fact using the blocklist setting in facter.conf

In PE 2019.8, you can block the generation of ec2_metadata, ec2_userdata, mountpoints, filesystems, or partitions facts using the blocklist setting in facter.conf, preventing all facts within the listed groups from being resolved when Facter runs.

If you can’t use those solutions, complete the following steps to create a module that overrides the fact. If you are using a version of PE that doesn’t support using blocklist, we recommend that you upgrade to the most recent long-term support version (PE 2021.7) . However, if that’s not possible, you can use the steps in this article to replace a fact with an empty string. In this example, the new module uses a custom fact to replace the mountpoints fact value with an empty string.

You can override a different fact by replacing mountpoints with a different fact.

1. Create a module: puppet module generate --skip-interview user-factoverride

2. Create a directory for your fact in the module: mkdir -p factoverride/lib/facter

3. Create a custom fact in the file factoverride/lib/facter/mountpoints_override.rb with the following contents:

   Facter.add(:mountpoints) do
     has_weight 100
   end

4. Deploy the module.

   If you use Code Manager: Deploy the module using Code Manager.

   If you do not use Code Manager: Deploy the module to the module directory for the desired environment.

5. As root, log into the primary server. Copy the new fact to the cache directory with pluginsync by running puppet agent -t. Your output should be similar to the following:

   Info: Using configured environment 'production' Info: Retrieving pluginfacts Info: Retrieving plugin Notice: /File[/opt/puppetlabs/puppet/cache/lib/facter/mountpoints_override.rb]/ensure: defined content as '{md5}7392c29fb7fe442b55196fc7aa8a92fb' Info: Loading facts Info: Caching catalog for puppetserver.domain.com Info: Applying configuration version '1c4bf0f741772f86cc7d91479a85b9d6b78f455d'

6. Verify that the override was successful by checking that mountpoints does not return any output. As root on the primary server run facter -p mountpoints.