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I just received a new book the other day: Pulling Strings With Puppet by James Turnbull. I got turned on to Puppet as a server management tool recently and wanted to try it out. There is a lot of good information on the Puppet project page, but I wanted a book, that spelled things out in a logical order. So far, I’m liking the book, and would recommend it to anybody looking to get into using Puppet.

For those unfamiliar with Puppet, its a configuration management utility that’s cross platform. You can run a central server with a client on each machine to be managed or just run the client with a configuration file. It makes more sense to use a central server in most cases though, but the latter is good for bootstrapping your initial server install and configuration before you can install Puppet. Puppet is nice because it is cross platform in the Unix/Linux world.

You don’t need to specificially know how to do things on each platform. You tell Puppet what you want and it will do it for you. For example:

file {
     "/etc/passwd":
     owner => "root",
     group => "root",
}

This sets ownership properties on the file /etc/passwd. You don’t need to know the commands to do so, just what you want the result to be. Its that simple.

Ryan puppet linux, puppet

I’ve been using virtualized systems for years now and finally began using Xen. Xen is similar to a bare-metal hypervisor like VMWare ESX but instead of using a proprietary host OS, Xen uses Linux. Most of the common Linux distros like Debian/Ubuntu, RHEL/Fedore/CentOS, etc provide support for Xen out of the box. I’m used to using Linux and have used it for years, so it just made sense.

Previously I had used VMWare Workstation for creating test servers, etc., but that required a full host operating system. For a while, I had used Windows, then I was using Linux, but it was still clunky. I had to manually start machines after reboot and if I upgraded the kernel on the host, I had to re-run some perl script to configure VMWare. After a while, I realized it was time to let go and do things the smart way, the Xen way. However, I do still use Parallels Desktop on my Mac just to have something available when I travel.

I have a custom server in my basement that I built a few years back and have modified over time. It has a 2TB RAID 5 array that I use for my network storage. It also has a dual-core AMD processor that I might swap out for a quad-core Phenom early next year. Just before rebuilding it as a Xen box, I upgraded the RAM to the maximum 8GB. Oh, and I added a 640GB drive to store my Xen machines.

I got the Xen Dom0 built the other week and have it running just enough to basically boot and allow me SSH access. This was really just a matter of doing a base install plus the Xen kernel and booting to the Xen kernel post-install. I kept the services to a minimum for security purposes and will run what’s needed off one of the DomU machines. Before I rebuilt this box with Xen, the host OS also doubled as the file and print server. This will be moved over to the first Xen DomU I create.

CentOS 5.2 comes with Xen 3.0 and unfortunately, none of the default repos have Xen built other than 3.0. Xen 3.0 is fairly outdated and I was looking to update to a more recent version to take advantage of the new features. The only options for updating were to upgrade/install from source or to use the wonderful Gitco repo that has a few Xen versions built for EL5 based operating systems.

I’m now the proud owner of a Xen box! I’ve learned quite a bit so far and have gotten my first DomU created. I’ll detail that more in a later post. I’m also looking at setting up Puppet to deploy and manage my machines. That’ll probably be the second DomU that I create.

Ryan Networking network, puppet, virtualization, xen