#!/usr/bin/python
"""
cluster.py: prototyping/experimentation for distributed Mininet,
aka Mininet: Cluster Edition
Author: Bob Lantz
Core classes:
RemoteNode: a Node() running on a remote server
RemoteOVSSwitch(): an OVSSwitch() running on a remote server
RemoteLink: a Link() on a remote server
Tunnel: a Link() between a local Node() and a RemoteNode()
These are largely interoperable with local objects.
- One Mininet to rule them all
It is important that the same topologies, APIs, and CLI can be used
with minimal or no modification in both local and distributed environments.
- Multiple placement models
Placement should be as easy as possible. We should provide basic placement
support and also allow for explicit placement.
Questions:
What is the basic communication mechanism?
To start with? Probably a single multiplexed ssh connection between each
pair of mininet servers that needs to communicate.
How are tunnels created?
We have several options including ssh, GRE, OF capsulator, socat, VDE, l2tp,
etc.. It's not clear what the best one is. For now, we use ssh tunnels since
they are encrypted and semi-automatically shared. We will probably want to
support GRE as well because it's very easy to set up with OVS.
How are tunnels destroyed?
They are destroyed when the links are deleted in Mininet.stop()
How does RemoteNode.popen() work?
It opens a shared ssh connection to the remote server and attaches to
the namespace using mnexec -a -g.
Is there any value to using Paramiko vs. raw ssh?
Maybe, but it doesn't seem to support L2 tunneling.
Should we preflight the entire network, including all server-to-server
connections?
Yes! We don't yet do this with remote server-to-server connections yet.
Should we multiplex the link ssh connections?
Yes, this is done automatically with ControlMaster=auto.
Note on ssh and DNS:
Please add UseDNS: no to your /etc/ssh/sshd_config!!!
Things to do:
- asynchronous/pipelined/parallel startup
- ssh debugging/profiling
- make connections into real objects
- support for other tunneling schemes
- tests and benchmarks
- hifi support (e.g. delay compensation)
"""
from mininet.node import Node, Host, OVSSwitch, Controller
from mininet.link import Link, Intf
from mininet.net import Mininet
from mininet.topo import LinearTopo
from mininet.topolib import TreeTopo
from mininet.util import quietRun, makeIntfPair, errRun, retry
from mininet.examples.clustercli import CLI
from mininet.log import setLogLevel, debug, info, error
from signal import signal, SIGINT, SIGHUP, SIG_IGN
from subprocess import Popen, PIPE, STDOUT
import os
from random import randrange
from sys import exit
import re
from distutils.version import StrictVersion
# BL note: so little code is required for remote nodes,
# we will probably just want to update the main Node()
# class to enable it for remote access! However, there
# are a large number of potential failure conditions with
# remote nodes which we may want to detect and handle.
# Another interesting point is that we could put everything
# in a mix-in class and easily add cluster mode to 2.0.
class RemoteMixin( object ):
"A mix-in class to turn local nodes into remote nodes"
# ssh base command
# -q: don't print stupid diagnostic messages
# BatchMode yes: don't ask for password
# ForwardAgent yes: forward authentication credentials
sshbase = [ 'ssh', '-q',
'-o', 'BatchMode=yes',
'-o', 'ForwardAgent=yes', '-tt' ]
def __init__( self, name, server='localhost', user=None, serverIP=None,
controlPath='/tmp/mn-%r@%h:%p', splitInit=False, **kwargs):
"""Instantiate a remote node
name: name of remote node
server: remote server (optional)
user: user on remote server (optional)
controlPath: ssh control path template (optional)
splitInit: split initialization?
**kwargs: see Node()"""
# We connect to servers by IP address
self.server = server if server else 'localhost'
self.serverIP = serverIP if serverIP else self.findServerIP( self.server )
self.user = user if user else self.findUser()
if self.user and self.server != 'localhost':
self.dest = '%s@%s' % ( self.user, self.serverIP )
self.isRemote = True
else:
self.isRemote = False
self.dest = None
self.controlPath = controlPath
self.sshcmd = []
if hasattr( self, 'server' ) and self.isRemote:
self.sshcmd = [ 'sudo', '-E', '-u', self.user ] + self.sshbase
if self.controlPath:
self.sshcmd += [ '-o', 'ControlPath=' + self.controlPath,
'-o', 'ControlMaster=auto' ]
self.sshcmd = self.sshcmd + [ self.dest ]
self.splitInit = splitInit
super( RemoteMixin, self ).__init__( name, **kwargs )
@staticmethod
def findUser():
"Try to return logged-in (usually non-root) user"
try:
# If we're running sudo
return os.environ[ 'SUDO_USER' ]
except:
try:
# Logged-in user (if we have a tty)
return quietRun( 'who am i' ).split()[ 0 ]
except:
# Give up and return effective user
return quietRun( 'whoami' )
# Determine IP address of local host
_ipMatchRegex = re.compile( r'\d+\.\d+\.\d+\.\d+' )
@classmethod
def findServerIP( cls, server ):
"Return our server's IP address"
# First, check for an IP address
ipmatch = cls._ipMatchRegex.findall( server )
if ipmatch:
return ipmatch[ 0 ]
# Otherwise, look up remote server
output = quietRun( 'getent ahostsv4 %s' % server )
ips = cls._ipMatchRegex.findall( output )
ip = ips[ 0 ] if ips else None
return ip
# Command support via shell process in namespace
def startShell( self, *args, **kwargs ):
"Start a shell process for running commands"
if hasattr( self, 'server' ) and self.isRemote:
kwargs.update( mnopts='-c' )
super( RemoteMixin, self ).startShell( *args, **kwargs )
if self.splitInit:
self.sendCmd( 'echo $$' )
else:
self.pid = int( self.cmd( 'echo $$' ) )
def finishInit( self ):
self.pid = int( self.waitOutput() )
def rpopen( self, *cmd, **opts ):
"Return a Popen object on underlying server in root namespace"
params = { 'stdin': PIPE,
'stdout': PIPE,
'stderr': STDOUT,
'sudo': True }
params.update( opts )
return self._popen( *cmd, **params )
def rcmd( self, *cmd, **opts):
"""rcmd: run a command on underlying server
in root namespace
args: string or list of strings
returns: stdout and stderr"""
popen = self.rpopen( *cmd, **opts )
# print 'RCMD: POPEN:', popen
# These loops are tricky to get right.
# Once the process exits, we can read
# EOF twice if necessary.
result = ''
while True:
poll = popen.poll()
result += popen.stdout.read()
if poll is not None:
break
return result
@staticmethod
def _ignoreSignal():
"Detach from process group to ignore all signals"
os.setpgrp()
def _popen( self, cmd, sudo=True, tt=True, **params):
"""Spawn a process on a remote node
cmd: remote command to run (list)
**params: parameters to Popen()
returns: Popen() object"""
if type( cmd ) is str:
cmd = cmd.split()
if hasattr( self, 'server' ) and self.isRemote:
if sudo:
cmd = [ 'sudo', '-E' ] + cmd
if tt:
cmd = self.sshcmd + cmd
else:
# Hack: remove -tt
sshcmd = list( self.sshcmd )
sshcmd.remove( '-tt' )
cmd = sshcmd + cmd
else:
if self.user and not sudo:
# Drop privileges
cmd = [ 'sudo', '-E', '-u', self.user ] + cmd
params.update( preexec_fn=self._ignoreSignal )
debug( '_popen', ' '.join(cmd), params )
popen = super( RemoteMixin, self )._popen( cmd, **params )
return popen
def popen( self, *args, **kwargs ):
"Override: disable -tt"
return super( RemoteMixin, self).popen( *args, tt=False, **kwargs )
def addIntf( self, *args, **kwargs ):
"Override: use RemoteLink.moveIntf"
return super( RemoteMixin, self).addIntf( *args,
moveIntfFn=RemoteLink.moveIntf, **kwargs )
class RemoteNode( RemoteMixin, Node ):
"A node on a remote server"
pass
class RemoteHost( RemoteNode ):
"A RemoteHost is simply a RemoteNode"
pass
class RemoteOVSSwitch( RemoteMixin, OVSSwitch ):
"Remote instance of Open vSwitch"
OVSVersions = {}
def isOldOVS( self ):
"Is remote switch using an old OVS version?"
cls = type( self )
if self.server not in cls.OVSVersions:
vers = self.cmd( 'ovs-vsctl --version' )
cls.OVSVersions[ self.server ] = re.findall( '\d+\.\d+', vers )[ 0 ]
return ( StrictVersion( cls.OVSVersions[ self.server ] ) <
StrictVersion( '1.10' ) )
class RemoteLink( Link ):
"A RemoteLink is a link between nodes which may be on different servers"
def __init__( self, node1, node2, **kwargs ):
"""Initialize a RemoteLink
see Link() for parameters"""
# Create links on remote node
self.node1 = node1
self.node2 = node2
self.tunnel = None
kwargs.setdefault( 'params1', {} )
kwargs.setdefault( 'params2', {} )
Link.__init__( self, node1, node2, **kwargs )
def stop( self ):
"Stop this link"
if self.tunnel:
self.tunnel.terminate()
self.tunnel = None
def makeIntfPair( self, intfname1, intfname2, addr1=None, addr2=None ):
"""Create pair of interfaces
intfname1: name of interface 1
intfname2: name of interface 2
(override this method [and possibly delete()]
to change link type)"""
node1, node2 = self.node1, self.node2
server1 = getattr( node1, 'server', 'localhost' )
server2 = getattr( node2, 'server', 'localhost' )
if server1 == 'localhost' and server2 == 'localhost':
# Local link
return makeIntfPair( intfname1, intfname2, addr1, addr2 )
elif server1 == server2:
# Remote link on same remote server
return makeIntfPair( intfname1, intfname2, addr1, addr2,
run=node1.rcmd )
# Otherwise, make a tunnel
self.tunnel = self.makeTunnel( node1, node2, intfname1, intfname2, addr1, addr2 )
return self.tunnel
@staticmethod
def moveIntf( intf, node, printError=True ):
"""Move remote interface from root ns to node
intf: string, interface
dstNode: destination Node
srcNode: source Node or None (default) for root ns
printError: if true, print error"""
intf = str( intf )
cmd = 'ip link set %s netns %s' % ( intf, node.pid )
node.rcmd( cmd )
links = node.cmd( 'ip link show' )
if not ( ' %s:' % intf ) in links:
if printError:
error( '*** Error: RemoteLink.moveIntf: ' + intf +
' not successfully moved to ' + node.name + '\n' )
return False
return True
def makeTunnel( self, node1, node2, intfname1, intfname2,
addr1=None, addr2=None ):
"Make a tunnel across switches on different servers"
# We should never try to create a tunnel to ourselves!
assert node1.server != 'localhost' or node2.server != 'localhost'
# And we can't ssh into this server remotely as 'localhost',
# so try again swappping node1 and node2
if node2.server == 'localhost':
return self.makeTunnel( node2, node1, intfname2, intfname1,
addr2, addr1 )
# 1. Create tap interfaces
for node in node1, node2:
# For now we are hard-wiring tap9, which we will rename
node.rcmd( 'ip link delete tap9', stderr=PIPE )
cmd = 'ip tuntap add dev tap9 mode tap user ' + node.user
node.rcmd( cmd )
links = node.rcmd( 'ip link show' )
# print 'after add, links =', links
assert 'tap9' in links
# 2. Create ssh tunnel between tap interfaces
# -n: close stdin
dest = '%s@%s' % ( node2.user, node2.serverIP )
cmd = [ 'ssh', '-n', '-o', 'Tunnel=Ethernet', '-w', '9:9',
dest, 'echo @' ]
self.cmd = cmd
tunnel = node1.rpopen( cmd, sudo=False )
# When we receive the character '@', it means that our
# tunnel should be set up
debug( 'Waiting for tunnel to come up...\n' )
ch = tunnel.stdout.read( 1 )
if ch != '@':
error( 'makeTunnel:\n',
'Tunnel setup failed for',
'%s:%s' % ( node1, node1.dest ), 'to',
'%s:%s\n' % ( node2, node2.dest ),
'command was:', cmd, '\n' )
tunnel.terminate()
tunnel.wait()
error( ch + tunnel.stdout.read() )
error( tunnel.stderr.read() )
exit( 1 )
# 3. Move interfaces if necessary
for node in node1, node2:
if node.inNamespace:
retry( 3, .01, RemoteLink.moveIntf, 'tap9', node )
# 4. Rename tap interfaces to desired names
for node, intf, addr in ( ( node1, intfname1, addr1 ),
( node2, intfname2, addr2 ) ):
if not addr:
node.cmd( 'ip link set tap9 name', intf )
else:
node.cmd( 'ip link set tap9 name', intf, 'address', addr )
for node, intf in ( ( node1, intfname1 ), ( node2, intfname2 ) ):
assert intf in node.cmd( 'ip link show' )
return tunnel
def status( self ):
"Detailed representation of link"
if self.tunnel:
if self.tunnel.poll() is not None:
status = "Tunnel EXITED %s" % self.tunnel.returncode
else:
status = "Tunnel Running (%s: %s)" % (
self.tunnel.pid, self.cmd )
else:
status = "OK"
result = "%s %s" % ( Link.status( self ), status )
return result
# Some simple placement algorithms for MininetCluster
class Placer( object ):
"Node placement algorithm for MininetCluster"
def __init__( self, servers=None, nodes=None, hosts=None,
switches=None, controllers=None, links=None ):
"""Initialize placement object
servers: list of servers
nodes: list of all nodes
hosts: list of hosts
switches: list of switches
controllers: list of controllers
links: list of links
(all arguments are optional)
returns: server"""
self.servers = servers or []
self.nodes = nodes or []
self.hosts = hosts or []
self.switches = switches or []
self.controllers = controllers or []
self.links = links or []
def place( self, node ):
"Return server for a given node"
# Default placement: run locally
return None
class RandomPlacer( Placer ):
"Random placement"
def place( self, nodename ):
"""Random placement function
nodename: node name"""
# This may be slow with lots of servers
return self.servers[ randrange( 0, len( self.servers ) ) ]
class RoundRobinPlacer( Placer ):
"""Round-robin placement
Note this will usually result in cross-server links between
hosts and switches"""
def __init__( self, *args, **kwargs ):
Placer.__init__( self, *args, **kwargs )
self.next = 0
def place( self, nodename ):
"""Round-robin placement function
nodename: node name"""
# This may be slow with lots of servers
server = self.servers[ self.next ]
self.next = ( self.next + 1 ) % len( self.servers )
return server
class SwitchBinPlacer( Placer ):
"""Place switches (and controllers) into evenly-sized bins,
and attempt to co-locate hosts and switches"""
def __init__( self, *args, **kwargs ):
Placer.__init__( self, *args, **kwargs )
# Easy lookup for servers and node sets
self.servdict = dict( enumerate( self.servers ) )
self.hset = frozenset( self.hosts )
self.sset = frozenset( self.switches )
self.cset = frozenset( self.controllers )
# Server and switch placement indices
self.placement = self.calculatePlacement()
@staticmethod
def bin( nodes, servers ):
"Distribute nodes evenly over servers"
# Calculate base bin size
nlen = len( nodes )
slen = len( servers )
# Basic bin size
quotient = int( nlen / slen )
binsizes = { server: quotient for server in servers }
# Distribute remainder
remainder = nlen % slen
for server in servers[ 0 : remainder ]:
binsizes[ server ] += 1
# Create binsize[ server ] tickets for each server
tickets = sum( [ binsizes[ server ] * [ server ]
for server in servers ], [] )
# And assign one ticket to each node
return { node: ticket for node, ticket in zip( nodes, tickets ) }
def calculatePlacement( self ):
"Pre-calculate node placement"
placement = {}
# Create host-switch connectivity map,
# associating host with last switch that it's
# connected to
switchFor = {}
for src, dst in self.links:
if src in self.hset and dst in self.sset:
switchFor[ src ] = dst
if dst in self.hset and src in self.sset:
switchFor[ dst ] = src
# Place switches
placement = self.bin( self.switches, self.servers )
# Place controllers and merge into placement dict
placement.update( self.bin( self.controllers, self.servers ) )
# Co-locate hosts with their switches
for h in self.hosts:
if h in placement:
# Host is already placed - leave it there
continue
if h in switchFor:
placement[ h ] = placement[ switchFor[ h ] ]
else:
raise Exception(
"SwitchBinPlacer: cannot place isolated host " + h )
return placement
def place( self, node ):
"""Simple placement algorithm:
place switches into evenly sized bins,
and place hosts near their switches"""
return self.placement[ node ]
class HostSwitchBinPlacer( Placer ):
"""Place switches *and hosts* into evenly-sized bins
Note that this will usually result in cross-server
links between hosts and switches"""
def __init__( self, *args, **kwargs ):
Placer.__init__( self, *args, **kwargs )
# Calculate bin sizes
scount = len( self.servers )
self.hbin = max( int( len( self.hosts ) / scount ), 1 )
self.sbin = max( int( len( self.switches ) / scount ), 1 )
self.cbin = max( int( len( self.controllers ) / scount ) , 1 )
info( 'scount:', scount )
info( 'bins:', self.hbin, self.sbin, self.cbin, '\n' )
self.servdict = dict( enumerate( self.servers ) )
self.hset = frozenset( self.hosts )
self.sset = frozenset( self.switches )
self.cset = frozenset( self.controllers )
self.hind, self.sind, self.cind = 0, 0, 0
def place( self, nodename ):
"""Simple placement algorithm:
place nodes into evenly sized bins"""
# Place nodes into bins
if nodename in self.hset:
server = self.servdict[ self.hind / self.hbin ]
self.hind += 1
elif nodename in self.sset:
server = self.servdict[ self.sind / self.sbin ]
self.sind += 1
elif nodename in self.cset:
server = self.servdict[ self.cind / self.cbin ]
self.cind += 1
else:
info( 'warning: unknown node', nodename )
server = self.servdict[ 0 ]
return server
# The MininetCluster class is not strictly necessary.
# However, it has several purposes:
# 1. To set up ssh connection sharing/multiplexing
# 2. To pre-flight the system so that everything is more likely to work
# 3. To allow connection/connectivity monitoring
# 4. To support pluggable placement algorithms
class MininetCluster( Mininet ):
"Cluster-enhanced version of Mininet class"
# Default ssh command
# BatchMode yes: don't ask for password
# ForwardAgent yes: forward authentication credentials
sshcmd = [ 'ssh', '-o', 'BatchMode=yes', '-o', 'ForwardAgent=yes' ]
def __init__( self, *args, **kwargs ):
"""servers: a list of servers to use (note: include
localhost or None to use local system as well)
user: user name for server ssh
placement: Placer() subclass"""
params = { 'host': RemoteHost,
'switch': RemoteOVSSwitch,
'link': RemoteLink,
'precheck': True }
params.update( kwargs )
servers = params.pop( 'servers', [ 'localhost' ] )
servers = [ s if s else 'localhost' for s in servers ]
self.servers = servers
self.serverIP = params.pop( 'serverIP', {} )
if not self.serverIP:
self.serverIP = { server: RemoteMixin.findServerIP( server )
for server in self.servers }
self.user = params.pop( 'user', RemoteMixin.findUser() )
if params.pop( 'precheck' ):
self.precheck()
self.connections = {}
self.placement = params.pop( 'placement', SwitchBinPlacer )
# Make sure control directory exists
self.cdir = os.environ[ 'HOME' ] + '/.ssh/mn'
errRun( [ 'mkdir', '-p', self.cdir ] )
Mininet.__init__( self, *args, **params )
def popen( self, cmd ):
"Popen() for server connections"
old = signal( SIGINT, SIG_IGN )
conn = Popen( cmd, stdin=PIPE, stdout=PIPE, close_fds=True )
signal( SIGINT, old )
return conn
def baddLink( self, *args, **kwargs ):
"break addlink for testing"
pass
def precheck( self ):
"""Pre-check to make sure connection works and that
we can call sudo without a password"""
result = 0
info( '*** Checking servers\n' )
for server in self.servers:
ip = self.serverIP[ server ]
if not server or server == 'localhost':
continue
info( server, '' )
dest = '%s@%s' % ( self.user, ip )
cmd = [ 'sudo', '-E', '-u', self.user ]
cmd += self.sshcmd + [ '-n', dest, 'sudo true' ]
debug( ' '.join( cmd ), '\n' )
out, err, code = errRun( cmd )
if code != 0:
error( '\nstartConnection: server connection check failed '
'to %s using command:\n%s\n'
% ( server, ' '.join( cmd ) ) )
result |= code
if result:
error( '*** Server precheck failed.\n'
'*** Make sure that the above ssh command works correctly.\n'
'*** You may also need to run mn -c on all nodes, and/or\n'
'*** use sudo -E.\n' )
exit( 1 )
info( '\n' )
def modifiedaddHost( self, *args, **kwargs ):
"Slightly modify addHost"
kwargs[ 'splitInit' ] = True
return Mininet.addHost( *args, **kwargs )
def placeNodes( self ):
"""Place nodes on servers (if they don't have a server), and
start shell processes"""
if not self.servers or not self.topo:
# No shirt, no shoes, no service
return
nodes = self.topo.nodes()
placer = self.placement( servers=self.servers,
nodes=self.topo.nodes(),
hosts=self.topo.hosts(),
switches=self.topo.switches(),
links=self.topo.links() )
for node in nodes:
config = self.topo.nodeInfo( node )
# keep local server name consistent accross nodes
if 'server' in config.keys() and config[ 'server' ] == None:
config[ 'server' ] = 'localhost'
server = config.setdefault( 'server', placer.place( node ) )
if server:
config.setdefault( 'serverIP', self.serverIP[ server ] )
info( '%s:%s ' % ( node, server ) )
key = ( None, server )
_dest, cfile, _conn = self.connections.get(
key, ( None, None, None ) )
if cfile:
config.setdefault( 'controlPath', cfile )
def addController( self, *args, **kwargs ):
"Patch to update IP address to global IP address"
controller = Mininet.addController( self, *args, **kwargs )
# Update IP address for controller that may not be local
if ( isinstance( controller, Controller)
and controller.IP() == '127.0.0.1'
and ' eth0:' in controller.cmd( 'ip link show' ) ):
Intf( 'eth0', node=controller ).updateIP()
return controller
def buildFromTopo( self, *args, **kwargs ):
"Start network"
info( '*** Placing nodes\n' )
self.placeNodes()
info( '\n' )
Mininet.buildFromTopo( self, *args, **kwargs )
def testNsTunnels():
"Test tunnels between nodes in namespaces"
net = Mininet( host=RemoteHost, link=RemoteLink )
h1 = net.addHost( 'h1' )
h2 = net.addHost( 'h2', server='ubuntu2' )
net.addLink( h1, h2 )
net.start()
net.pingAll()
net.stop()
# Manual topology creation with net.add*()
#
# This shows how node options may be used to manage
# cluster placement using the net.add*() API
def testRemoteNet( remote='ubuntu2' ):
"Test remote Node classes"
print '*** Remote Node Test'
net = Mininet( host=RemoteHost, switch=RemoteOVSSwitch,
link=RemoteLink )
c0 = net.addController( 'c0' )
# Make sure controller knows its non-loopback address
Intf( 'eth0', node=c0 ).updateIP()
print "*** Creating local h1"
h1 = net.addHost( 'h1' )
print "*** Creating remote h2"
h2 = net.addHost( 'h2', server=remote )
print "*** Creating local s1"
s1 = net.addSwitch( 's1' )
print "*** Creating remote s2"
s2 = net.addSwitch( 's2', server=remote )
print "*** Adding links"
net.addLink( h1, s1 )
net.addLink( s1, s2 )
net.addLink( h2, s2 )
net.start()
print 'Mininet is running on', quietRun( 'hostname' ).strip()
for node in c0, h1, h2, s1, s2:
print 'Node', node, 'is running on', node.cmd( 'hostname' ).strip()
net.pingAll()
CLI( net )
net.stop()
# High-level/Topo API example
#
# This shows how existing Mininet topologies may be used in cluster
# mode by creating node placement functions and a controller which
# can be accessed remotely. This implements a very compatible version
# of cluster edition with a minimum of code!
remoteHosts = [ 'h2' ]
remoteSwitches = [ 's2' ]
remoteServer = 'ubuntu2'
def HostPlacer( name, *args, **params ):
"Custom Host() constructor which places hosts on servers"
if name in remoteHosts:
return RemoteHost( name, *args, server=remoteServer, **params )
else:
return Host( name, *args, **params )
def SwitchPlacer( name, *args, **params ):
"Custom Switch() constructor which places switches on servers"
if name in remoteSwitches:
return RemoteOVSSwitch( name, *args, server=remoteServer, **params )
else:
return RemoteOVSSwitch( name, *args, **params )
def ClusterController( *args, **kwargs):
"Custom Controller() constructor which updates its eth0 IP address"
controller = Controller( *args, **kwargs )
# Find out its IP address so that cluster switches can connect
Intf( 'eth0', node=controller ).updateIP()
return controller
def testRemoteTopo():
"Test remote Node classes using Mininet()/Topo() API"
topo = LinearTopo( 2 )
net = Mininet( topo=topo, host=HostPlacer, switch=SwitchPlacer,
link=RemoteLink, controller=ClusterController )
net.start()
net.pingAll()
net.stop()
# Need to test backwards placement, where each host is on
# a server other than its switch!! But seriously we could just
# do random switch placement rather than completely random
# host placement.
def testRemoteSwitches():
"Test with local hosts and remote switches"
servers = [ 'localhost', 'ubuntu2']
topo = TreeTopo( depth=4, fanout=2 )
net = MininetCluster( topo=topo, servers=servers,
placement=RoundRobinPlacer )
net.start()
net.pingAll()
net.stop()
#
# For testing and demo purposes it would be nice to draw the
# network graph and color it based on server.
# The MininetCluster() class integrates pluggable placement
# functions, for maximum ease of use. MininetCluster() also
# pre-flights and multiplexes server connections.
def testMininetCluster():
"Test MininetCluster()"
servers = [ 'localhost', 'ubuntu2' ]
topo = TreeTopo( depth=3, fanout=3 )
net = MininetCluster( topo=topo, servers=servers,
placement=SwitchBinPlacer )
net.start()
net.pingAll()
net.stop()
def signalTest():
"Make sure hosts are robust to signals"
h = RemoteHost( 'h0', server='ubuntu1' )
h.shell.send_signal( SIGINT )
h.shell.poll()
if h.shell.returncode is None:
print 'OK: ', h, 'has not exited'
else:
print 'FAILURE:', h, 'exited with code', h.shell.returncode
h.stop()
if __name__ == '__main__':
setLogLevel( 'info' )
# testRemoteTopo()
# testRemoteNet()
# testMininetCluster()
# testRemoteSwitches()
signalTest()