gtuhl: startup IT and software development

I’ve become a pretty huge fan of openSUSE. The installer is excellent, it just works really well and I really like having the option of yast to manage most aspects of the system, even when working from a command line. In comparison to RHEL it has more file system options, newer/more rpms in the official repositories, and in my opinion yast is superior to RHEL’s up2date. If support is an issue you can get Suse Enterprise Linux preinstalled by hardware vendors (including Dell) as well as enterprise support from Novell.

Though the openSUSE installer is pretty solid manually booting, configuring, installing, and updating an OS can get old really fast especially if you are installing on machines meant to have the same or similar roles. As part of the effort to improve our ability to manage more machines at work I decided to explore two tools to make life easier:

• Setting up our own installation server
• Using autoyast to automate 95% of the install for new machines

I generally followed the guidance offered at this novell.com page but want to walk through the specific process I went through as well as some specific gotchas and details in the hopes of helping out anybody else trying to do the same with 64bit openSUSE 10.2 on servers. By “on servers” I mean “no x windows”.

Setting up the Installation Server

If you have an existing openSUSE box setting up the installation server is pretty easy. Here are the steps involved in setting the server up and linking it to the official Novell yast repostories so your new installations get updated packages.

• Run yast and goto Software -> Software Management
• Search for and install yast2-instserver
• Exit and restart yast and goto Miscellaneous -> Installation Server
• From here you will be walked through the process of copying the files from your installation media to the HD and exposing the sources with FTP, HTTP, or NFS
• For this particular example I went with FTP, openSUSE installed and attempted to configure vsftp
• I had to manually /sbin/service vsftpd start to make it work.
• By default vsftp was configured to allow only anonymous access with read-only permissions, and /srv/ftp was set as the root of what anonymous can see on the disk, so the config was perfect by default.
• The full path to the 64bit installation source CD contents was /srv/ftp/sources/suse-10.2-64bit/. It is a good idea to give the source directory a specific name as that allows you to add alternate sources (like 32bit) to the same installation server in the future.
• Go to /srv/ftp/sources/suse-10.2-64bit/CD1 and create a new file named add_on_products.
• Edit this new file and enter any number of source repositories that you want to be included in new installs - 1 on each line. In my case it looked like this:
  http://download.opensuse.org/distribution/10.2/repo/oss
http://download.opensuse.org/distribution/10.2/repo/non-oss
http://download.suse.com/update/10.2
• Sources entered here will also automatically be registered as installation sources for the new machines. If you aren’t using 10.2 your source repositories will be different. Check this page for all of them.
• That wraps up the installation server. Assuming the vsftp service started up you are good to go.

At this point, you can setup new openSUSE machines by installing against this server. You would need to boot the machine with some sort of openSUSE installation media (the DVD, CD1, a properly setup usb key, or the minimal install CD) to get to the installation menu. From there hit F4, enter your FTP installation server and the /sources/suse-10.2-64bit/CD1 directory, press enter, and then continue with the installation. Having the installation server is really nice because you can control and manage a single, consistent set of rpms.

Setting up autoyast

Just having a central installation server is great but with autoyast you can almost completely automate installation of new openSUSE servers. This works by creating an autoyast control file at which you point new installations. The control file can include instructions for disk partitioning, installed software, services, custom config files, and directions to run extra scripts at various stages of the installation. The link at the top of this post provides a pretty good overview and the documentation here is very helpful as well. That documentation provides almost all of the information you need so where details are excluded from the following look there.

In my specific case (an autoyast file for JBoss servers) the process went like this:

• Uploaded the latest versions of JBoss and Java (yast didn’t have 1.5), init.d scripts for JBoss, as well as our custom /etc/profile.d/environment.sh file to the installation server under a different directory accessible through FTP.
• Wrote a script meant to run after new installs to download and configure the above. Really just a bunch of wgets, copying, linking, chmod/chown changes. This was going to be downloaded and run in the init-scripts stage of the autoyast install.
• Setup a fresh install of openSUSE exactly as I wanted it for a JBoss server and ran yast2 autoyast from the command line.
• Selected Tools -> Create Reference Profile
• Selected the areas I cared about including. Note that selections here are in addition to a default set of information that includes partitioning and installed packages. In my case Firewall, Online Update Config (I enabled this on the reference server), Local Security, and User Management made sense.
• Next was to add a custom sshd_config file. With the reference profile loaded, went to Miscellaneous -> Complete Configuration Files and then alt-E for configure.
• Alt-w for new, file path of /etc/ssh/sshd_config for the new installs, and the loaded the contents of my existing sshd_config file for the contents.
• Lastly, I wanted to run the script I mentioned above as an init-script. These are scripts which run after installation is complete and networking is functional on a new server. init-scripts cannot be configured through the autoyast tool so I did File -> Save As and generated my baseline autoyast file.
• If you see warnings about the format of the generated xml file (the autoyast control file) ignore them. The Suse team has issues with their schema files.
• Finally, I edited the autoyast file and added my init-script to the end. It looked like this:
  
<scripts>
  <init-scripts config:type="list">
    <script>
      <location>ftp://myserver/myscript.sh</location>
      <interpreter>shell</interpreter>
    </script>
  </init-scripts>
</scripts>

  
• Then I just uploaded this file to the same FTP server so it was accessible during new installs.

Though the number of steps I just listed seems long, these autoyast files are really very quick to make. You could create any number of them for different machine roles and make them all available for new installs.

Setting up a New Server

Now that you have an installation server (FTP-based in this specific case) and all the autoyast files and other resources a new machine could need, you can setup a new machine from scratch by doing the following:

• Boot from the openSUSE DVD, CD1, or minimal installation CD. With some more work you can setup a bootable usb key or use the PXE boot capability of newer machines to boot from a network resource.
• Once you see the installation menu, Hit F4, enter your FTP installation server and the /sources/suse-10.2-64bit/CD1 directory, press enter.
• Move the cursor over the Installation option and type autoyast=ftp://[installserver]/[autoyast-file]. What you type appears in the command line options along the bottom of the screen.
• Press enter and walk away from the machine for awhile so the installation can complete.

Now, when I set this up, GRUB wouldn’t boot the newly installed machine. It turned out that the kernel version I was running on the reference server (and from which I generated the initial autoyast file) was different from the kernel provided by the installation server. This meant in my autoyast file the GRUB configuration portion was trying to reference a file (vmlinuz-2.6.18.2-34-default) that didn’t exist. So make sure your installation server is tied to the official repositories and make sure your reference machine is fully up to date before creating the baseline autoyast file.

I used this same approach to create configurations for JBoss, e-mail, and basic openSUSE-based servers.