Upgrade Puppet Server

Upgrade Puppet Server to adopt features and functionality of newer versions.

Upgrading the puppetserver package effectively upgrades Puppet Server. The puppetserver package, in turn, depends on the puppet-agent package. In the following procedure, the command in step 1 upgrades both the puppetserver and puppet-agent packages on the host.

Important: During an upgrade, Puppet Server doesn't perform its usual functions, including maintaining your site's infrastructure. If you use a single primary server, plan the timing of your upgrade accordingly and avoid reconfiguring any managed servers until your primary server is back up. If you use multiple load-balanced servers, upgrade them individually to avoid downtime or problems synchronizing configurations.

On your Puppet Server node, run the command appropriate to your package installer:
Yum:
```
yum update puppet-agent puppetserver
```
Apt:
```
apt-get update
apt-get install --only-upgrade puppet-agent puppetserver
```
If you pinned Puppet packages to a specific version, remove the pins.

For yum packages locked with the versionlock plugin, edit /etc/yum/pluginconf.d/versionlock.list to remove the lock.
On apt systems, remove .pref files from /etc/apt/preferences.d/ that pin packages, and use the apt-mark unhold command on each held package.
Run a full restart of the puppetserver service.