def stopFlow():
"""
Stops ongoing iperf client sessions that were previously
orchestrated by the TG.
"""
#Retrieve Traffic Generator Slave Object
tgslave = app.config['TGS']
t = time.strftime("%H:%M:%S", time.gmtime())
log.info("%s - StopFlow command from Traffic Generator arrived\n"%t)
# Get flow information
flow = flask.request.json
aux = Base()
size = aux.setSizeToStr(flow['size'])
# Log it
log.info("\t* Stopping iperf client session of flow...\n")
log.info("\t - src: %s:%s\n"%(flow['src'], flow['sport']))
log.info("\t - dst: %s:%s\n"%(flow['dst'], flow['dport']))
log.info("\t - size: %s\n"%size)
log.info("\t - duration: %s\n"%str(flow['duration']))
# Kill ongoing flow
flow_already_there = [(p, f) for (p, f) in tgslave.iperf_sessions.iteritems() if f == flow]
if flow_already_there != []:
# Get process handler
p = flow_already_there[0][0]
# Terminate it
p.terminate()
# Remove from dictionary
tgslave.iperf_sessions.pop(p)
else:
log.info("\t* Error: non-existing flow\n")
def startFlow():
"""This function will be running in each of the hosts in our
network. It essentially waits for commands from the
TrafficGenerator in the Json-Rest interface and creates a
subprocess for each corresponding iperf client sessions to other
hosts.
"""
try:
# Retrieve Traffic Generator Slave object
tgslave = app.config['TGS']
t = time.strftime("%H:%M:%S", time.gmtime())
log.info("%s - StartFlow command from Traffic Generator arrived\n"%t)
# Get flow information
flow = flask.request.json
aux = Base()
size = aux.setSizeToStr(flow['size'])
# Log it
log.info("\t* Starting iperf client command...\n")
log.info("\t - src: %s:%s\n"%(flow['src'], flow['sport']))
log.info("\t - dst: %s:%s\n"%(flow['dst'], flow['dport']))
log.info("\t - size: %s\n"%size)
log.info("\t - duration: %s\n"%str(flow['duration']))
# Add process handler to dictionary
flow_already_there = [(p, f) for (p, f) in tgslave.iperf_sessions.iteritems() if f == flow]
if flow_already_there != []:
# If same flow exists already, restart it
previous_p = flow_already_there[0][0]
previous_p.terminate()
tgslave.iperf_sessions.pop(p)
# Start iperf client session
p = Popen(["iperf", "-c", flow['dst'], "-u", "-b", size, "-t",
str(flow['duration']), "-p", str(flow['dport'])])
tgslave.iperf_sessions[p] = flow
except:
log.info("ERROR:\n")
log.info("LOG: Exception in user code:\n")
log.info('-'*60+'\n')
log.info(traceback.print_exc())
log.info('-'*60+'\n')