As with all Munki tutorials, this one assumes you already know some Munki basics. If you don't, you might want to start with Absolute beginner's guide to setting up Munki (not monkey).
When you use munkiimport to import software packages, it will either find icons automatically or prompt you to try to extract icons from the package. In some cases, the extraction doesn't work, and you may have to create an icon manually.
First, go into your munki_repo and then within the pkgsinfo subdirectory, find your package info. As an example, we'll use Inkscape. Open it up in a text editor (e.g., TextWrangler).
Alternate Method to Find Names: If you run
Mac software packages usually have a .icns file for the icon, but Munki is looking for a .png, so we'll do a conversion.
Troubleshooting Suggestion: If your icons still aren't showing up, and you're 100% certain the name matches, the permissions may be wrong. I thought 644 on the icons directory content would be a enough (read/write for owner, read for everyone else), but I had to change it to 755 recursively to get all the icons to work, for some reason.
More details at the Munki Google Code page about icon guidelines.