Remove more hard-coded stuff

route-0.py

@@ -9,44 +9,54 @@ from mininet.cli import CLI
 from util.router import Router
 from util.experiment import Experiment
 
+FRR_BIN_DIR = "/usr/lib/frr"
+
 
 def start_daemon(node, daemon, conf_dir):
     """Start one FRR daemon on a given node.
 
     """
-    node.cmd("/usr/lib/frr/{daemon}"
+    node.cmd("{bin_dir}/{daemon}"
              " -f {conf_dir}/{node_name}.conf"
              " -d"
              " -i /tmp/{node_name}-{daemon}.pid"
              " > /tmp/{node_name}-{daemon}.out 2>&1"
-             .format(daemon=daemon, conf_dir=conf_dir, node_name=node.name))
+             .format(bin_dir=FRR_BIN_DIR,
+                     daemon=daemon,
+                     conf_dir=conf_dir,
+                     node_name=node.name))
     node.waitOutput()
 
 
-def run(scenario):
-    """Start a network scenario.
+def clean():
+    """Clean all state left over from a previous experiment.
+
     """
-
-    daemons = [
-        "zebra",
-        "staticd",
-        "isisd",
-    ]
-
     os.system("rm -f /tmp/R*.log /tmp/R*.pid /tmp/R*.out")
     os.system("rm -f /tmp/h*.log /tmp/h*.pid /tmp/h*.out")
     os.system("mn -c >/dev/null 2>&1")
-    os.system("killall -9 {} > /dev/null 2>&1".format(' '.join(daemons)))
+    os.system("killall -9 {} > /dev/null 2>&1"
+              .format(' '.join(os.listdir(FRR_BIN_DIR))))
 
-    net = Mininet(topo=scenario.topo(), switch=Router)
+
+def run(experiment):
+    """Start a network experiment.
+
+    """
+
+    # Clean up any state from previous experiments.
+    clean()
+
+    # Start Mininet.
+    net = Mininet(topo=experiment.topo(), switch=Router)
     net.start()
 
     # WARNING: FRR can get confused unless all daemons on each node are started
     #          together.
     for node in net.switches:
-        for daemon in daemons:
-            if node.name in getattr(scenario, daemon, set()):
-                conf_dir = getattr(scenario, "{}_conf".format(daemon))
+        for daemon in experiment.daemons:
+            if node.name in getattr(experiment, daemon, set()):
+                conf_dir = getattr(experiment, "{}_conf".format(daemon))
                 start_daemon(node, daemon, conf_dir)
 
         if node.name.startswith('R'):
@@ -60,18 +70,26 @@ def run(scenario):
 
     CLI(net)
     net.stop()
-    os.system("killall -9 {} > /dev/null 2>&1".format(' '.join(daemons)))
+    os.system("killall -9 {}".format(' '.join(experiment.daemons)))
 
 
-if __name__ == "__main__":
+def main():
+    """Route 0 entry point.
+
+    """
+
     parser = argparse.ArgumentParser(
-        description='Launch a network scenario Mininet.')
+        description='Launch an FRR network experiment in Mininet.')
     parser.add_argument('--topology', '-t', type=str, required=True,
                         help='the topology of the network')
     parser.add_argument('--scenario', '-s', type=str, required=True,
                         help='the scenario to set up in the network')
-    ARGS = parser.parse_args()
+    args = parser.parse_args()
 
-    experiment = Experiment(ARGS.topology, ARGS.scenario)
+    experiment = Experiment(args.topology, args.scenario)
 
     run(experiment)
+
+
+if __name__ == "__main__":
+    main()

util/experiment.py

@@ -27,6 +27,9 @@ class Experiment(object):
                       .import_module('topology.{}.topo'.format(topology))
                       .NetTopo)
 
+        # Initialise list of daemons.
+        self.daemons = []
+
         # Return now if the scenario is "plain".
         if scenario == "plain":
             return
@@ -56,6 +59,11 @@ class Experiment(object):
         # Each daemon entry should be a directory.
         daemon_dir = os.path.join(parent_dir, daemon)
         if os.path.exists(daemon_dir) and os.path.isdir(daemon_dir):
+            # Make sure zebra is always first on the list of daemons.
+            if daemon == "zebra":
+                self.daemons.insert(0, daemon)
+            else:
+                self.daemons.append(daemon)
             setattr(self, daemon, set())
             setattr(self, "{}_conf".format(daemon), daemon_dir)