How to do it...

Use Puppet's inline_template function, which allows you to execute Ruby code:

cron { "run-puppet":
    command => "/usr/sbin/puppet agent --test",
    minute  => inline_template("<%= hostname.hash.abs % 60 %>"),
}

service { "puppet":
    ensure => stopped,
    enable => false,
}

How it works...

Because each hostname produces a unique hash value, each client will run Puppet at a different minute past the hour. This hashing technique is useful for randomizing any cron jobs to improve the odds that they won't interfere with each other.

There's more...

You may find that running Puppet as a daemon leaks memory over time, or that occasionally Puppet can get into a stuck state when communicating with the master. Running Puppet from cron should also fix these problems.

There are other ways to trigger Puppet runs, including the MCollective tool, which we'll cover in detail elsewhere in this book.

See also