Using nxtoolkit to Generate a Cable Plan from a Running Topology

Getting Started with Cable-Plan

The Cable-Plan application module is imported from :file:cableplan.py which can be found in the nxtoolkit/applications/cableplan directory.

It can be incorporated directly into a Python script, or it can be used from the command-line.

    from cableplan import CABLEPLAN  

To create a cable-plan from the current running Nexus switch, simply do the following:

    cp = CABLEPLAN.get(session)  

where session is a Nexus switch session object generated using the nxtoolkit, cp will be the cable-plan object.

Export that cable-plan by opening a file and calling the export() method as follows:

    cpFile = open('cableplan1.xml','w')  
    cp.export(cpFile)  
    cpFile.close()  

The cable-plan will be written to the :file:cableplan1.xml file.

Working with Saved Cable-Plans

Reading an existing cable-plan xml file is equally easy:

    fileName = 'cableplan2.xml'  
    cp2 = CABLEPLAN.get(fileName)  

Note that you don't have to explicitly open or close the file. The get(fileName) method will handle this.

Comparing Cable-Plans

Comparing cable-plans is one of the more interesting capabilities of the cable-plan module and is very easy to do using "difference" methods. When generating the difference between two cable-plans, the module will return those items that exist in the first cable-plan, but not in the second.

Missing Switches

For example, assume that in the above example, the second cable-plan read from the :file:cableplan2.xml file does not have switch "Spine3" and the first cable-plan does have it. The following example will print all of the switches in the first cable-plan and not in the second:

  missing_switches = cp1.difference_switch(cp2)  
  for switch in missing_switches :  
      print switch.get_name()  

This should print the following output:

Spine3

Missing Links

Similiarly, the following example will print all of the missing links:

  missing_links = cp1.difference_link(cp2)  
  for link in missing_links :  
      print link.get_name()  

New and Missing Links

To understand all of the differences between two cable-plans it is necessary to compare them in both directions:

  missing_links = cp1.difference_link(cp2)  
  extra_links = cp2.difference_link(cp1)  
  print 'The following links are missing from the second cable-plan'
  for link in missing_links :  
      print link.get_name()  
  print 'The following links are extra links in the second cable-plan'  
  for link in extra_links:  
      print link.get_name()