satellite_systemid.py

#!/bin/env python

import xml.etree.ElementTree as ET

tree = ET.parse("/etc/sysconfig/rhn/systemid")
doc = tree.getroot()

for member in tree.findall('param/value/struct/member'):
    if member.find('name').text == 'system_id':
        systemid = member.find('value').find('string').text
        if systemid.startswith('ID-'):
            systemid = systemid[3:]

print "satellite_systemid=" + systemid