In which module sub-directory should custom facts be placed to allow for synchronization using plugin sync?

Custom facts are designed to extend the capabilities of Facter, the tool Puppet uses to gather information about the system. To ensure these custom facts synchronize properly across environments, they must be placed in a specific location within the module structure.

The correct location for placing custom facts is in the 'lib/facter' directory. This is because Facter looks within the 'lib/facter' sub-directory of each module to find custom fact definitions. By placing them here, you ensure that during the plugin sync process, these facts are synchronized and available to all agents that pull the module from the Puppet master.

Other locations such as 'facts/', 'custom_facts/', and 'lib/custom_facts' are not recognized by Facter as valid directories for loading custom fact definitions. Therefore, keeping custom facts organized in 'lib/facter' is essential for proper functionality and synchronization across your Puppet environment.