Bruce's Blog

The following lines of code when used within Zenoss's zendmd environment will take a list of IP addresses from a text file and spit out a list of those IP addresses that do not yet have a corresponding object in Zenoss.

import string

print [devip for devip in map(string.strip, open("iplist.txt", "r").readlines())
    if not [True for device in dmd.Devices.getSubDevices() if device.manageIp == devip]]

This is useful for those cases where you are sure Zenoss discovery missed a few network switches due to a network administrator screwup and find that it's too time consuming to find the handful among hundreds the manual way.

As for the code quality I beg forgiveness from the Pythonic gods for thinking a list comprehension within a list comprehension with a map thrown in was a good idea. But then again I'm sure there are some Ruby fanatics out there that think that looks like Hello World. ;)

Update on May 13th: A kind poster pointed out the presence of find() in zendmd and thus dmd.Devices.findDevice(). That means one can just do this instead:

import string

print [devip for devip in map(string.strip, open("iplist.txt", "r").readlines())
    if not dmd.Devices.findDevice(devip)]

Not only is it shorter its also a magnitude of order faster which shouldn't be too surprising considering the evil in the original version. Thanks Erik!