Software Update, go!

I spend the day installing a centralized update server on on of our Mac Mini Servers (on SL).

Apple provides a service called "Software Update" to accomplish this. 

Configuration is strait forward, just enable it in the Server Admin, configure the destination directory for the update cache and wait for it to finish downloading. Easy as it should be. 

As we have a mixed environment of Snow Leopard and Lion, the update server needs to host both types. 

This needs a few modifications in the config files. And this is where it gets ugly. 

Apple has documented the configuration here:

http://support.apple.com/kb/HT4771

Sadly, it does not work like that. Maybe it did one time, it does not anymore.
In short, two files need to be edited but these get changed back every time the service starts again. Apple fail.

Thx to leifsehn, I've found the correct way to do this: 

Hello All...I originally was having the same issue with the files reverting back to the original but I was able to get the lion updates working by doing the following: 

1. Login to your server as root, turn off SUS and Quit Server Admin.
2. Goto /System/Library/PrivateFrameworks/SUServer.framework/Versions/A/Resources/
3. Edit the swupd.conf to contain the new lion entry as per apple.
4. Delete the swupd.conf that is located in /etc/swupd
5. Run the command "sudo /usr/libexec/PlistBuddy -c 'add :otherCatalogs:2 string index-lion-snowleopard-leopard.merged-1.sucatalog' /etc/swupd/swupd.plist"
6. Resart the server
7. Start the Server Admin and Start the SUS.
8. Now the server should be reflecting the new Lion Updates.

Tested this with a managed computer and after I enabled the Lion updates I was able to instalt the 10.7.1 update.

Hope this helps. 

Source: https://discussions.apple.com/message/15962462#15962462

You can check if it's working correctly by accessing the Software Update repository in a browser:

http://softwareupdate.pretentco.com:8088/index.sucatalog

You should see an XML starting with "<?xml version="1.0" encoding="UTF-8"?>"

Great, so now SL and Lion updates are on the system, nothing left to stop us, right?
Well, the clients need to be configured. But I'll do that tomorrow...