Added ripcord.py, which attempts to make a FatTree using ripcord and

instantiate a mininet Network based on its topology.

Also minor cleanup of nox.py and GridNet class in mininet.py.

examples/nox.py

@@ -2,7 +2,6 @@
 
 "Instantiate a Tree network and use NOX as the controller."
 
-import time
 from mininet import init, Controller, TreeNet, Cli
 
 class NoxController( Controller ):

examples/ripcord.py

@@ -0,0 +1,50 @@
+#!/usr/bin/python
+
+"A FatTree network, using Brandon Heller's ripcord system."
+
+from ripcord.topo import StructuredNode, StructuredNodeSpec, FatTreeTopo, VL2T
+opo
+
+from mininet import Controller, Network, Host, pingTest
+
+class NoxController( Controller ):
+   "A customized Controller that uses NOX."
+   def __init__( self, name, **kwargs ):
+      Controller.__init__( self, name, 
+         controller='nox_core', cargs='-i ptcp pyswitch', 
+         cdir='/usr/local/bin', **kwargs)
+   
+class FatTree( Network ):
+   "A customized Network that uses ripcord's FatTree."
+   def __init__( self, **kwargs ):
+      Network.__init__( self, depth, **kwargs )
+   def makeNetwork( self, controller ):
+      ft = FatTreeTopo( depth )
+      graph = ft.g
+      switches = []
+      hosts = []
+      hostnames = nameGen( 'h0' )
+      switchnames = nameGen( 's0' )
+      graphToMini = {}
+      miniToGraph = {}
+      # Create nodes
+      for graphNode in graph.nodes():
+         print "found node", graphNode
+         isLeaf = len( graph.neighbors( graphNode ) ) = 1
+         if isLeaf:
+            mininetNode = Node( hostnames.next() )
+            hosts += [ mininetNode ]
+         else:
+            mininetNode = self.Switch( switchnames.next() )
+            switches += [ mininetNode ]
+            miniToGraph[ mininetNode ] = graphNode
+            graphToMini[ graphNode ] = mininetNode
+      # Create Links
+      for switch in switches:
+         for neighbor in miniToGraph[ switches ]:
+            makeLink( switch, graphToMini[ neighbor ] )
+
+if __name__ == '__main__':
+   init()   
+   network = FatTree( depth=4, kernel=True, Controller=NoxController)
+   network.run( pingTest )