After upgrading, you should do a few more things to make Puppet easier to maintain.
Reconfigure systems that use Puppet’s data
Puppet 4 changed the locations of many configuration files. If you have any other systems that reuse Puppet’s SSL credentials, configuration data, or generated data, point them to the new directories.
Update backup jobs
If you back up data in directories that moved (like
/etc/puppet, whose contents are now split between
/etc/puppetlabs/code), update your backup jobs to use the new locations.
/etc/puppet directory on *nix systems
Avoid maintenance and configuration confusion by deleting the old
/etc/puppet directory on your *nix systems. This prevents other systems from using stale data and protects sysadmins from accidentally updating the wrong copies of files.
Delete the per-environment
puppet_agent class from nodes
puppet_agent module doesn’t affect nodes running Puppet >=4, and you can unassign it from all nodes after your entire Puppet infrastructure is upgraded.