adding natnet example test

examples/test/test_natnet.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+
+"""
+Test for natnet.py
+"""
+
+import unittest
+import pexpect
+from mininet.util import quietRun
+
+class testNATNet( unittest.TestCase ):
+
+    prompt = 'mininet>'
+
+    def setUp( self ):
+        self.net = pexpect.spawn( 'python -m mininet.examples.natnet' )
+        self.net.expect( self.prompt )
+
+    def testPublicPing( self ):
+        "Attempt to ping the public server (h0) from h1 and h2"
+        self.net.sendline( 'h1 ping -c 1 h0' )
+        self.net.expect ( '(\d+)% packet loss' )
+        percent = int( self.net.match.group( 1 ) ) if self.net.match else -1
+        self.assertEqual( percent, 0 )
+        self.net.expect( self.prompt )
+
+        self.net.sendline( 'h2 ping -c 1 h0' )
+        self.net.expect ( '(\d+)% packet loss' )
+        percent = int( self.net.match.group( 1 ) ) if self.net.match else -1
+        self.assertEqual( percent, 0 )
+        self.net.expect( self.prompt )
+
+    def testPrivatePing( self ):
+        "Attempt to ping h1 and h2 from public server"
+        self.net.sendline( 'h0 ping -c 1 -t 1 h1' )
+        result = self.net.expect ( [ 'unreachable', 'loss' ] )
+        self.assertEqual( result, 0 )
+        self.net.expect( self.prompt )
+
+        self.net.sendline( 'h0 ping -c 1 -t 1 h2' )
+        result = self.net.expect ( [ 'unreachable', 'loss' ] )
+        self.assertEqual( result, 0 )
+        self.net.expect( self.prompt )
+
+    def testPrivateToPrivatePing( self ):
+        "Attempt to ping from NAT'ed host h1 to NAT'ed host h2"
+        self.net.sendline( 'h1 ping -c 1 -t 1 h2' )
+        result = self.net.expect ( [ '[Uu]nreachable', 'loss' ] )
+        self.assertEqual( result, 0 )
+        self.net.expect( self.prompt )
+
+    def tearDown( self ):
+        self.net.sendline( 'exit' )
+        self.net.wait()
+
+if __name__ == '__main__':
+    unittest.main()