Managing packages, services, and files

We will move on from this manual configuration and become familiar with Puppet as a central configuration server, whereby we can define settings within manifest files that will be distributed to the required nodes. To begin this, we will create the manifest file; these are just text files, and apply it locally on the Puppet master using puppet apply. Once we have verified that the manifest is working and enforcing the desired state, we will enlist the clients and see true Puppet automation at work.

The building blocks for Puppet start with the resource declarations that we have already looked at. These declarations are written to manifest files, which have the extension .pp. Within the manifest file, resources can be grouped together into classes. A class often represents related resources, such as the openssh-server package, the sshd service, and the /etc/ssh/sshd_config configuration file. It would seem reasonable to group these resources together...