初試mininet(可選PyCharm)

目錄

• 0x00 Mininet
• 0x01 Important classes, methods, functions
• 0x02 Sample
• 0x04 run in shell
• 0x05 Output
• 0x06 Problems
• 0x07 Paint

0x00 Mininet

嘗試理解一下mininet,話說mininet是基於python編寫的，代碼結構清晰，簡直清醒脫俗（~(≧▽≦)/~啦啦啦），附上連接mininet,mark一下。

0x01 Important classes, methods, functions

簡單記錄一下比較重要的類和方法

Important classes, methods, functions and variables in the above code include:

Topo: the base class for Mininet topologies

build(): The method to override in your topology class. Constructor parameters (n) will be passed through to it automatically by Topo.__init__().

addSwitch(): adds a switch to a topology and returns the switch name

addHost(): adds a host to a topology and returns the host name

addLink(): adds a bidirectional link to a topology (and returns a link key, but this is not important). Links in Mininet are bidirectional unless noted otherwise.

Mininet: main class to create and manage a network

start(): starts your network

pingAll(): tests connectivity by trying to have all nodes ping each other

stop(): stops your network

net.hosts: all the hosts in a network

dumpNodeConnections(): dumps connections to/from a set of nodes.

setLogLevel( 'info' | 'debug' | 'output' ): set Mininet's default output level; 'info' is recommended as it provides useful information.

0x02 Sample

本身寫了一個簡單的，h1~h5連接到s1, h6~h10連接到s2,而後s1和s2互聯
一開始想着SingleSwitchTopo的方法來寫LinearTopo，結果一直報錯，╮(╯_╰)╭，明明人家代碼都寫好了
SingleSwitchTopo是Single switch connected to k hosts，而Linear topology of k switches, with n hosts per switch

#!/usr/bin/python

from mininet.topo import Topo
from mininet.net import Mininet
from mininet.util import irange,dumpNodeConnections
from mininet.log import setLogLevel

class LinearTopo(Topo):
    ""
    """Linear topology of k switches, with n hosts per switch."""
    ""
    def __init__(self, k=2, n=5,**opts):

        """k:number of switches (and hosts)"""
        """hconf: host configuration options"""
        """lconf: ling configuration options"""
        super(LinearTopo, self).__init__(**opts)
        self.n = n
        self.k = k
        """creates 2 switchs"""
        switch1 = self.addSwitch('s1')
        switch2 = self.addSwitch('s2')

        """creates h1~h5 and addLink switch1"""

        for i in irange(1,n):
            host = self.addHost('h%s' %i)
            self.addLink(host,switch1)

        """creates h6~h10 and addLink switch2"""

        for i in irange(n+1,n+5):
            host =self.addHost('h%s' %i)
            self.addLink(host,switch2)

        """addLink switch1 and switch2"""
        self.addLink(switch1,switch2)


def simpleTest():
    "Create and test a simple network"
    topo = LinearTopo(k=2,n=5)
    net = Mininet(topo)
    #start the network
    net.start()
    print "Dumping host connections"
    dumpNodeConnections(net.hosts)

    #test the connections of the network
    print "Testing network connectivity"
    net.pingAll()

    #Test the bandwidth of the h* and h*
    print "Testing bandwidth between h1 and h2"
    h1, h2 = net.get('h1', 'h2')
    net.iperf((h1,h2))

    print "Testing bandwidth between h10 and h1"
    h10, h1 = net.get('h10', 'h1')
    net.iperf((h10,h1))


    #stop the network
    net.stop()

if __name__== '__main__':
    # Tell mininet to print useful information
    setLogLevel('info')
    simpleTest()

0x04 run in shell

命令行直接運行

#將代碼保存到一個文件中
sudo vi test.py

#運行
sudo python test.py

0x05 Output

*** Creating network
*** Adding controller
*** Adding hosts:
h1 h2 h3 h4 h5 h6 h7 h8 h9 h10 
*** Adding switches:
s1 s2 
*** Adding links:
(h1, s1) (h2, s1) (h3, s1) (h4, s1) (h5, s1) (h6, s2) (h7, s2) (h8, s2) (h9, s2) (h10, s2) (s1, s2) 
*** Configuring hosts
h1 h2 h3 h4 h5 h6 h7 h8 h9 h10 
*** Starting controller
c0 
*** Starting 2 switches
s1 s2 ...
Dumping host connections
h1 h1-eth0:s1-eth1
h2 h2-eth0:s1-eth2
h3 h3-eth0:s1-eth3
h4 h4-eth0:s1-eth4
h5 h5-eth0:s1-eth5
h6 h6-eth0:s2-eth1
h7 h7-eth0:s2-eth2
h8 h8-eth0:s2-eth3
h9 h9-eth0:s2-eth4
h10 h10-eth0:s2-eth5
Testing network connectivity
*** Ping: testing ping reachability
h1 -> h2 h3 h4 h5 h6 h7 h8 h9 h10 
h2 -> h1 h3 h4 h5 h6 h7 h8 h9 h10 
h3 -> h1 h2 h4 h5 h6 h7 h8 h9 h10 
h4 -> h1 h2 h3 h5 h6 h7 h8 h9 h10 
h5 -> h1 h2 h3 h4 h6 h7 h8 h9 h10 
h6 -> h1 h2 h3 h4 h5 h7 h8 h9 h10 
h7 -> h1 h2 h3 h4 h5 h6 h8 h9 h10 
h8 -> h1 h2 h3 h4 h5 h6 h7 h9 h10 
h9 -> h1 h2 h3 h4 h5 h6 h7 h8 h10 
h10 -> h1 h2 h3 h4 h5 h6 h7 h8 h9 
*** Results: 0% dropped (90/90 received)
Testing bandwidth between h1 and h2
*** Iperf: testing TCP bandwidth between h1 and h2 
*** Results: ['35.8 Gbits/sec', '35.8 Gbits/sec']
Testing bandwidth between h10 and h1
*** Iperf: testing TCP bandwidth between h10 and h1 
*** Results: ['36.4 Gbits/sec', '36.4 Gbits/sec']
*** Stopping 1 controllers
c0 
*** Stopping 11 links
...........
*** Stopping 2 switches
s1 s2 
*** Stopping 10 hosts
h1 h2 h3 h4 h5 h6 h7 h8 h9 h10 
*** Done

0x06 Problems

遇到的問題:
一.Mininet只能使用python2使用python3不行，即便用外部庫也不行，
二.PyCharm配置root運行文件
一開始我沒有使用shell來運行，而是使用了PyCharm來跑，而後出現了一個問題，就是Mininet must run as a root,即必須以管理員身份進行，因此須要在PyCharm上設置管理員運行，具體作法：

• 1.在/usr/bin/目錄下新建文件 python_sudo.sh ：

sudo gedit /usr/bin/python_sudo.sh

在文件中寫入下列代碼：

#! /bin/bash 
sudo python $*

• 2.給sh文件賦予權限：

cd /usr/bin/
sudo chmod a+x python_sudo.sh

• 3.編輯visudo(其餘工具備點問題):

sudo visudo

• 4.在最後一行輸入,而後保存：

%sudo ALL=NOPASSWD: /usr/bin/python

• 5.將pycharm 中的

File→Settings→Project Interpreter
置換爲本身寫的python_sudo.sh，在下圖選中框右邊有個小齒輪，點那個進行Add就OK了

• 6.同理能夠對python3等進行設定，只要在將python改爲對應版本就能夠(前提是在這個目錄下已安裝)

0x07 Paint

一個能用畫圖工具

sudo apt-get install kolourpaint4

而後搜paint就OK了