Puppet Master-Agent Communication Model

We are done with concepts like Why Puppet, PE Stack, Puppet Master/Agent Installation:
Start Automation with Puppet
Puppet Enterprise Stack
Puppet Enterprise Master Installation
Puppet Agent Installation

Its time to understand the communication mechanism for Puppet Master-Agent Model. The whole communication of Puppet relies on three terms called Facts, Catalogs and Reports.

1.) Facts: There is an inbuilt tool called “Facter” in puppet which comes with Puppet Agent Package. This tools is responsible to collect all of the running node (client) information and send that to the puppet master server in the form of facts. In simple layman language facts is the client’s running state information.

2.) Catalogs: Upon receiving the facts from the client, Puppet Master compare the client running state with the actual configured configuration state in Master server. Based upon the comparison Puppet complies a Catalog and send it across to the client to makes changes if there are any drifts in the configuration or acknowledge if the configuration is all okay as per configured in Master server.

3.) Reports: All of the drifts (configuration changes) done in the clients are reported back to the Master Server in the form of reports.

Note: You can use third party tools for reports, Puppet provides many 3rd party API’s for the same.

We will learn about the Puppet Certification Management in our next post through which Puppet Master and Client’s establish their connections and follow Puppet Master-Agent Communication Model.