To install Puppet on CentOS 7, you can basically follow these instructions.

Notes:

1. Don’t forget to open the firewall: firewall-cmd --zone=public --add-port=8140/tcp --permanent firewall-cmd --reload
2. You may have to put SELinux into permissive mode to allow Apache read the config.ru owned by puppet.

To permanently switch from WEBrick to Apache, configure systemd like this:

systemctl disable puppetmaster
systemctl enable httpd

Install client agent on RedHat/CentOS

1. Pick the correct repository for your version from PuppetLabs.
2. Install it:
   yum install puppet
3. If needed, configure the Puppetmaster server name in /etc/puppet/puppet.conf:
   [agent]
server = mypuppetmaster.example.org
4. Finally, add the cronjob¹There’s also a way to let the puppet agent run as a service described here, but this can have an impact on cpu and memory usage.:
   puppet resource cron puppet-agent ensure=present user=root minute=30 command='/usr/bin/puppet agent --onetime --no-daemonize --splay'

• 1
  There’s also a way to let the puppet agent run as a service described here, but this can have an impact on cpu and memory usage.