实验7:基于REST API的SDN北向应用实践

一.将所有本实验相关文件保存在目录/home/用户名/学号/lab7/中
二.(一)只需要提交实现相应Python代码和执行结果截图,其余文字请勿赘述;
(二)不做必须要求,有完成的同学请提交Python代码和运行结果,文件保存目录参照要求2。
1.编写Python程序,调用OpenDaylight的北向接口实现以下功能
(1) 利用Mininet平台搭建下图所示网络拓扑,并连接OpenDaylight;
a.打开odl控制器

./distribution-karaf-0.6.4-Carbon/bin/karaf

b.创建拓扑

sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13


(2) 下发指令删除s1上的流表数据。
a.delete.py代码

#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
if __name__ == "__main__":
    url = 'http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/'
    headers = {'Content-Type': 'application/json'}
    res = requests.delete(url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print (res.content)

b.结果截图

(3) 下发硬超时流表,实现拓扑内主机h1和h3网络中断20s。
a.flowtimeout.json代码

{
  "flow": [
    {
      "id": "1",
      "match": {
        "in-port": "1",
        "ethernet-match": {
          "ethernet-type": {
            "type": "0x0800"
          }
        },
        "ipv4-destination": "10.0.0.3/32"
      },
      "instructions": {
        "instruction": [
          {
            "order": "0",
            "apply-actions": {
              "action": [
                {
                  "order": "0",
                  "drop-action": {}
                }
              ]
            }
          }
        ]
      },
      "flow-name": "flow",
      "priority": "65535",
      "hard-timeout": "20",
      "cookie": "2",
      "table_id": "0"
    }
  ]
}

b.put.py文件

#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
if __name__ == "__main__":
    url = 'http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/'
    headers = {'Content-Type': 'application/json'}
    res = requests.delete(url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print (res.content)

c.结果截图

(4) 获取s1上活动的流表数
a.get.py的代码

#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
if __name__ == "__main__":
    url = 'http://127.0.0.1:8181/restconf/operational/opendaylight-inventory:nodes/node/openflow:1/flow-node-inventory:table/0/opendaylight-flow-table-statistics:flow-table-statistics'
    headers = {'Content-Type': 'application/json'}
    res = requests.get(url,headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print (res.content)

b.结果截图

2.编写Python程序,调用Ryu的北向接口实现以下功能
a.关闭ODL控制器,关闭上次的拓扑并清除拓扑后

sudo mn -c

b.打开Ryu控制器

ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest

c.创建拓扑

sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

(1) 实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。
a.编写ryu_timeout.py 代码

import requests
from requests.auth import HTTPBasicAuth

if __name__ == '__main__':
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    headers = {'Content-Type': 'application/json'}
    json = open('ryu_timeout.json').read()
    response = requests.post(url, data=json, headers=headers)
    print(response.content)

b.编写ryu_timeout.json代码

{
    "dpid": 1,
    "cookie": 1,
    "cookie_mask": 1,
    "table_id": 0,
    "hard_timeout": 20,
    "priority": 65535,
    "flags": 1,
    "match":{
        "in_port":1
    },
    "actions":[]
 }

c.创建一个拓扑

sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

d.开启ryu服务

ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest

e.先进行h1 ping h2 的操作后运行ryu_timeout的代码

(2) 参考Ryu REST API的文档,基于VLAN实验的网络拓扑,编程实现相同的VLAN配置。
提示:拓扑生成后需连接Ryu,且Ryu应能够提供REST API服务
a.编写ryu_topo.py代码

from mininet.topo import Topo
 
class ryu_topo(Topo):
    def __init__(self):
        Topo.__init__(self)

        self.addSwitch("s1")
        self.addSwitch("s2")
 
        self.addHost("h1")
        self.addHost("h2")
        self.addHost("h3")
        self.addHost("h4")
 
        self.addLink("s1", "h1")
        self.addLink("s1", "h2")
        self.addLink("s2", "h3")
        self.addLink("s2", "h4")
        self.addLink("s1", "s2")
 
topos = {'ryu_topo': (lambda: ryu_topo())}

b.编写ryu_vlan.py代码

import json
import requests

if __name__ == '__main__':
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    headers = {'Content-Type': 'application/json'}
    f = open('ryu_vlan.json').read()
    flows = json.loads(f)['flows']
    [requests.post(url, data=json.dumps(flows[i]), headers=headers) for i in range(0, 8)]


c.编写ryu_vlan.json代码

{
	"flows": [
        {
			"dpid": 1,
			"priority": 1,
			"match": {
				"in_port": 1
			},
			"actions": [{
					"type": "PUSH_VLAN",
					"ethertype": 33024
				},
				{
					"type": "SET_FIELD",
					"field": "vlan_vid",
					"value": 4096
				},
				{
					"type": "OUTPUT",
					"port": 3
				}
			]
		},
		{
			"dpid": 1,
			"priority": 1,
			"match": {
				"in_port": 2
			},
			"actions": [{
					"type": "PUSH_VLAN",
					"ethertype": 33024
				},
				{
					"type": "SET_FIELD",
					"field": "vlan_vid",
					"value": 4097
				},
				{
					"type": "OUTPUT",
					"port": 3
				}
			]
		},
		{
			"dpid": 1,
			"priority": 1,
			"match": {
				"vlan_vid": 0
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 1
				}
			]
		},
		{
			"dpid": 1,
			"priority": 1,
			"match": {
				"vlan_vid": 1
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 2
				}
			]
		},
		{
			"dpid": 2,
			"priority": 1,
			"match": {
				"in_port": 1
			},
			"actions": [{
					"type": "PUSH_VLAN",
					"ethertype": 33024
				},
				{
					"type": "SET_FIELD",
					"field": "vlan_vid",
					"value": 4096
				},
				{
					"type": "OUTPUT",
					"port": 3
				}
			]
		}, 
        {
			"dpid": 2,
			"priority": 1,
			"match": {
				"in_port": 2
			},
			"actions": [{
					"type": "PUSH_VLAN",
					"ethertype": 33024
				},
				{
					"type": "SET_FIELD",
					"field": "vlan_vid",
					"value": 4097
				},
				{
					"type": "OUTPUT",
					"port": 3
				}
			]
		},
		{
			"dpid": 2,
			"priority": 1,
			"match": {
				"vlan_vid": 0
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 1
				}
			]
		},
		{
			"dpid": 2,
			"priority": 1,
			"match": {
				"vlan_vid": 1
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 2
				}
			]
		}
	]
}


d.创建一个拓扑并清空流表

sudo mn --custom ryu_topo.py --topo ryu_topo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/1
curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/2

e.打开ryu

ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest

f.运行ryu_vlan.py代码,并pingall

三.进阶要求
OpenDaylight或Ryu任选其一,编程实现查看前序VLAN实验拓扑中所有节点(含交换机、主机)的名称,以及显示每台交换机的所有流表项。
1)getnodes.py

import requests
import time
import re


class GetNodes:
    def __init__(self, ip):
        self.ip = ip
        
    def get_switch_id(self):
        url = 'http://' + self.ip + '/stats/switches'
        re_switch_id = requests.get(url=url).json()
        switch_id_hex = []
        for i in re_switch_id:
            switch_id_hex.append(hex(i))

        return switch_id_hex

    def getflow(self):
        url = 'http://' + self.ip + '/stats/flow/%d'
        switch_list = self.get_switch_id()
        ret_flow = []
        for switch in switch_list:
            new_url = format(url % int(switch, 16))
            re_switch_flow = requests.get(url=new_url).json()
            ret_flow.append(re_switch_flow)
        return ret_flow

    def show(self):
        flow_list = self.getflow()
        for flow in flow_list:
            for dpid in flow.keys():
                dp_id = dpid
                switchnum= '{1}'.format(hex(int(dp_id)), int(dp_id))        
                print('s'+switchnum,end = " ")
                switchnum = int(switchnum)
            for list_table in flow.values():
                for table in list_table:          
                    string1 = str(table)
                    if re.search("'dl_vlan': '(.*?)'", string1) is not None:
                        num = re.search("'dl_vlan': '(.*?)'", string1).group(1);
                        if num == '0' and switchnum == 1:
                            print('h1',end = " ")
                        if num == '1' and switchnum == 1:
                            print('h2',end = " ")
                        if num == '0' and switchnum == 2:
                            print('h3',end = " ")
                        if num == '1' and switchnum == 2:
                            print('h4',end = " ")
        print("")
        flow_list = self.getflow()
        for flow in flow_list:
            for dpid in flow.keys():
                dp_id = dpid
                print('switch_name:s{1}'.format(hex(int(dp_id)), int(dp_id)))
            for list_table in flow.values():
                for table in list_table:
                    print(table)
s1 = GetNodes("127.0.0.1:8080")
s1.show()

2)运行代码后查看对应的流表项

四.个人总结,包括但不限于实验难度、实验过程遇到的困难及解决办法,个人感想,不少于200字
实验的目的是要求我们能够编写程序调用OpenDaylight REST API实现特定网络功能,能够编写程序调用Ryu REST API实现特定网络功能。
对于我来说,实验的难度还是有点大,很多代码还是比较灵活,所以参考了很多同学的代码,完成了这次实验。由于实验要求的Ubuntu要20.04然后我在实验的时候发现ryu开启不了,询问后发现是python3.10版本与ryu不兼容,但是本身的ubuntu是22版本自带python3.10,查阅资料修改python版本后系统崩溃,就重新安装了个ubuntu20.04版本。

posted on 2022-11-02 19:20  Qwertyuzxc  阅读(31)  评论(0编辑  收藏  举报