Add xterm support

mininet/net.py

@@ -47,6 +47,7 @@ Naming:
 """
 import os
 import re
+import signal
 from subprocess import call
 import sys
 from time import sleep
@@ -54,6 +55,7 @@ from time import sleep
 from mininet.logging_mod import lg
 from mininet.util import quietRun, fixLimits
 from mininet.util import make_veth_pair, move_intf, retry, MOVEINTF_DELAY
+from mininet.xterm import cleanUpScreens, makeXterms
 
 DATAPATHS = ['kernel'] #['user', 'kernel']
 
@@ -101,6 +103,8 @@ class Mininet(object):
         self.in_namespace = in_namespace
         self.switch_is_kernel = switch_is_kernel
 
+        self.terms = [] # list of spawned xterm processes
+
         self.kernel = True #temporary!
 
         if build:
@@ -286,7 +290,30 @@ class Mininet(object):
         self._config_hosts()
 
         if xterms:
-            pass # build xterms
+            self.start_xterms()
+
+    def switch_nodes(self):
+        '''Return switch nodes.'''
+        return [self.nodes[dpid] for dpid in self.topo.switches()]
+
+    def host_nodes(self):
+        '''Return host nodes.'''
+        return [self.nodes[dpid] for dpid in self.topo.hosts()]
+
+    def start_xterms(self):
+        '''Start an xterm for each node in the topo.'''
+        lg.info("*** Running xterms on %s\n" % os.environ['DISPLAY'])
+        cleanUpScreens()
+        self.terms += makeXterms(self.controllers.values(), 'controller')
+        self.terms += makeXterms(self.switch_nodes(), 'switch')
+        self.terms += makeXterms(self.host_nodes(), 'host')
+
+    def stop_xterms(self):
+        '''Kill each xterm.'''
+        # Kill xterms
+        for term in self.terms:
+            os.kill(term.pid, signal.SIGKILL)
+        cleanUpScreens()
 
     def start(self):
         '''Start controller and switches\n'''
@@ -303,6 +330,9 @@ class Mininet(object):
 
     def stop(self):
         '''Stop the controller(s), switches and hosts\n'''
+        if self.terms:
+            lg.info('*** Stopping %i terms\n' % len(self.terms))
+            self.stop_xterms()
         lg.info('*** Stopping %i hosts\n' % len(self.topo.hosts()))
         for host_dpid in self.topo.hosts():
             host = self.nodes[host_dpid]

mininet/xterm.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+"""XTerm creation and cleanup.
+
+Utility functions to run an xterm (connected via screen(1)) on each host.
+
+Requires xterm(1) and GNU screen(1).
+"""
+
+import os
+import re
+from subprocess import Popen
+
+from mininet.util import quietRun
+
+def makeXterm(node, title):
+    '''Run screen on a node, and hook up an xterm.
+
+    @param node Node object
+    @param title base title
+    @return process created
+    '''
+    title += ': ' + node.name
+    if not node.inNamespace:
+        title += ' (root)'
+    cmd = ['xterm', '-title', title, '-e']
+    if not node.execed:
+        node.cmdPrint('screen -dmS ' + node.name)
+        cmd += ['screen', '-D', '-RR', '-S', node.name]
+    else:
+        cmd += ['sh', '-c', 'exec tail -f /tmp/' + node.name + '*.log']
+    return Popen(cmd)
+
+
+def cleanUpScreens():
+    '''Remove moldy old screen sessions.'''
+    r = r'(\d+.[hsc]\d+)'
+    output = quietRun('screen -ls').split('\n')
+    for line in output:
+        m = re.search(r, line)
+        if m:
+            quietRun('screen -S ' + m.group(1) + ' -X kill')
+
+
+def makeXterms(nodes, title):
+    '''Create XTerms.
+
+    @param nodes list of Node objects
+    @param title base title for each
+    @return list of created xterm processes
+    '''
+    return [makeXterm(node, title) for node in nodes]