update examples scripts, replacing add_to_server() with two-line statement

note that due to the usage of the 'server' global, it will not work to add a
Session.add_to_server() or core.misc.utils.add_to_server() function
(Boeing r1828)

daemon/examples/netns/distributed.py

@@ -25,17 +25,6 @@ coreapi.add_node_class("CORE_NODE_SWITCH",
 # node list (count from 1)
 n = [None]
 
-def add_to_server(session):
-    ''' Add this session to the server's list if this script is executed from
-    the core-daemon server.
-    '''
-    global server
-    try:
-        server.addsession(session)
-        return True
-    except NameError:
-        return False
-
 def main():
     usagestr = "usage: %prog [-h] [options] [args]"
     parser = optparse.OptionParser(usage = usagestr)
@@ -68,7 +57,8 @@ def main():
 
     prefix = ipaddr.IPv4Prefix("10.83.0.0/16")
     session = pycore.Session(persistent=True)
-    add_to_server(session)
+    if 'server' in globals():
+        server.addsession(session)
 
     # distributed setup - connect to slave server
     slaveport = options.slave.split(':')

daemon/examples/netns/emane80211.py

@@ -16,17 +16,6 @@ from core.emane.ieee80211abg import EmaneIeee80211abgModel
 # node list (count from 1)
 n = [None]
 
-def add_to_server(session):
-    ''' Add this session to the server's list if this script is executed from
-    the core-daemon server.
-    '''
-    global server
-    try:
-        server.addsession(session)
-        return True
-    except NameError:
-        return False
-
 def main():
     usagestr = "usage: %prog [-h] [options] [args]"
     parser = optparse.OptionParser(usage = usagestr)
@@ -62,7 +51,8 @@ def main():
     session.location.refscale = 150.0
     session.cfg['emane_models'] = "RfPipe, Ieee80211abg, Bypass, AtdlOmni"
     session.emane.loadmodels()
-    add_to_server(session)
+    if 'server' in globals():
+        server.addsession(session)
 
     # EMANE WLAN
     print "creating EMANE WLAN wlan1"

daemon/examples/netns/iperf-performance-chain.py

@@ -23,17 +23,6 @@ from core.constants import *
 # node list (count from 1)
 n = [None]
 
-def add_to_server(session):
-    ''' Add this session to the server's list if this script is executed from
-    the core-daemon server.
-    '''
-    global server
-    try:
-        server.addsession(session)
-        return True
-    except NameError:
-        return False
-
 def main():
     usagestr = "usage: %prog [-h] [options] [args]"
     parser = optparse.OptionParser(usage = usagestr)
@@ -64,7 +53,8 @@ def main():
     start = datetime.datetime.now()
 
     session = pycore.Session(persistent=True)
-    add_to_server(session)
+    if 'server' in globals():
+        server.addsession(session)
     print "creating %d nodes"  % options.numnodes
     left = None
     prefix = None

daemon/examples/netns/switch.py

@@ -14,17 +14,6 @@ from core.constants import *
 # node list (count from 1)
 n = [None]
 
-def add_to_server(session):
-    ''' Add this session to the server's list if this script is executed from
-    the core-daemon server.
-    '''
-    global server
-    try:
-        server.addsession(session)
-        return True
-    except NameError:
-        return False
-
 def main():
     usagestr = "usage: %prog [-h] [options] [args]"
     parser = optparse.OptionParser(usage = usagestr)
@@ -54,7 +43,8 @@ def main():
     # IP subnet
     prefix = ipaddr.IPv4Prefix("10.83.0.0/16")
     session = pycore.Session(persistent=True)
-    add_to_server(session)
+    if 'server' in globals():
+        server.addsession(session)
     # emulated Ethernet switch
     switch = session.addobj(cls = pycore.nodes.SwitchNode, name = "switch")
     switch.setposition(x=80,y=50)