Typing Puppet Strings Onto Your Servers

Just like a good Perl programmer, a system administrator should strive for a certain degree of laziness.

Now, this is not the kind of laziness that leads one to think "Eh, I'm not going to bother installing that update." No, this is the form of efficient laziness that says "I could download and install that update, but there's got to be a way to get it done automatically without wasting my time." These are the kind of people who have libraries of shell scripts and packed cron jobs.

Now, those libraries of shell scripts are great, but they can be an awful lot of work to write and maintain. Not very lazy at all! So, rather than going that route, I've been working with (and on) a package called Puppet.

Puppet is a client/server package written in Ruby. Essentially, you configure the server with the configuration settings you want all of your machines to look like. The clients get pointed at the server, pull all of their settings down, and make them happen.

It's got a decent library of native types (such as packages, files, users, etc) right out of the box. If you need something that's not covered, it's fairly straightforward to write your own custom code (assuming you know Ruby) that allows you to extend what kinds of files and setting Puppet is able to directly manage. Thanks to some good helper libraries, I was able to whip up a custom module that allows me to manage entries in /etc/sysctl.conf is only 59 lines of code!

Some of the cooler features of Puppet:

• All communication is XML-RPC based, making it easier to write custom programs that communicate with Puppet
• Collections of facts about client systems (OS, OS version, etc) are reported back to the server and can be stored in a database
• Defines and Exec allow you to create complex configurations without writing any Ruby code
• ERb templating system (the same one of Ruby on Rails fame) allows you to generate complex configuration files with per-host settings

Ask anyone who manages big numbers of systems - hundreds, or thousands - and they'll tell you that the ability to automatically manage systems from provision to decommission without manual intervention is absolutely essential. Whether it's built in, like GPO in Windows, or an add-on package like Puppet, trying to manage any more than one or two systems without this kind of help is just making more work for yourself.

And that's not very lazy at all.