Files
mininet/examples/multiping.py
T
lantz f0c726a42f Use /usr/bin/env python for virtualenv (#1025)
This helps with virtualenv although it can open
up another security hole if you end up using an
unexpected python interpreter.

Overall it seems to make sense to err on the side
of usability but it's good to be aware of security.

However, for the remaining utility scripts that require
python 2, we explicitly note this with #!/usr/bin/python2.
2021-02-05 07:42:50 -08:00

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Python
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#!/usr/bin/env python
"""
multiping.py: monitor multiple sets of hosts using ping
This demonstrates how one may send a simple shell script to
multiple hosts and monitor their output interactively for a period=
of time.
"""
from select import poll, POLLIN
from time import time
from mininet.net import Mininet
from mininet.node import Node
from mininet.topo import SingleSwitchTopo
from mininet.log import info, setLogLevel
def chunks( l, n ):
"Divide list l into chunks of size n - thanks Stackoverflow"
return [ l[ i: i + n ] for i in range( 0, len( l ), n ) ]
def startpings( host, targetips ):
"Tell host to repeatedly ping targets"
targetips = ' '.join( targetips )
# Simple ping loop
cmd = ( 'while true; do '
' for ip in %s; do ' % targetips +
' echo -n %s "->" $ip ' % host.IP() +
' `ping -c1 -w 1 $ip | grep packets` ;'
' sleep 1;'
' done; '
'done &' )
info( '*** Host %s (%s) will be pinging ips: %s\n' %
( host.name, host.IP(), targetips ) )
host.cmd( cmd )
def multiping( netsize, chunksize, seconds):
"Ping subsets of size chunksize in net of size netsize"
# Create network and identify subnets
topo = SingleSwitchTopo( netsize )
net = Mininet( topo=topo, waitConnected=True )
net.start()
hosts = net.hosts
subnets = chunks( hosts, chunksize )
# Create polling object
fds = [ host.stdout.fileno() for host in hosts ]
poller = poll()
for fd in fds:
poller.register( fd, POLLIN )
# Start pings
for subnet in subnets:
ips = [ host.IP() for host in subnet ]
# adding bogus to generate packet loss
ips.append( '10.0.0.200' )
for host in subnet:
startpings( host, ips )
# Monitor output
endTime = time() + seconds
while time() < endTime:
readable = poller.poll(1000)
for fd, _mask in readable:
node = Node.outToNode[ fd ]
info( '%s:' % node.name, node.monitor().strip(), '\n' )
# Stop pings
for host in hosts:
host.cmd( 'kill %while' )
net.stop()
if __name__ == '__main__':
setLogLevel( 'info' )
multiping( netsize=20, chunksize=4, seconds=10 )