实验7：基于REST API的SDN北向应用实践..

标签：__ .. url flow REST switch API table id

（一）基本要求

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；

   

   

   （2） 下发指令删除s1上的流表数据。

2. #!/usr/bin/python
   import requests
   from requests.auth import HTTPBasicAuth

   def http_delete(url):
   url= url
   headers = {'Content-Type':'application/json'}
   resp = requests.delete(url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
   return resp

   if __name__ == "__main__":
   url = 'http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/'
   resp = http_delete(url)
   print(resp.content)

3. （3） 下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。

    

4. # timeout.py
   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/flow-node-inventory:table/0/flow/1'
   with open("./timeOut.json") as file:
   str = file.read()
   headers = {'Content-Type': 'application/json'}
   res = requests.put(url, str, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
   print (res.content)

5. # timeout.json
   {
   "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"
   }
   ]
   }

6. （4） 获取s1上活动的流表数。
   

   # getflow.py
   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)

7. 编写Python程序，调用Ryu的北向接口实现以下功能
   （1） 实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。

   （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。

   

    

   二）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。

   GetNode.py

   

    1 import requests
    2 import time
    3 import re
    4 
    5 
    6 class GetNodes:
    7     def __init__(self, ip):
    8         self.ip = ip
    9         
   10     def get_switch_id(self):
   11         url = 'http://' + self.ip + '/stats/switches'
   12         re_switch_id = requests.get(url=url).json()
   13         switch_id_hex = []
   14         for i in re_switch_id:
   15             switch_id_hex.append(hex(i))
   16 
   17         return switch_id_hex
   18 
   19     def getflow(self):
   20         url = 'http://' + self.ip + '/stats/flow/%d'
   21         switch_list = self.get_switch_id()
   22         ret_flow = []
   23         for switch in switch_list:
   24             new_url = format(url % int(switch, 16))
   25             re_switch_flow = requests.get(url=new_url).json()
   26             ret_flow.append(re_switch_flow)
   27         return ret_flow
   28 
   29     def show(self):
   30         flow_list = self.getflow()
   31         for flow in flow_list:
   32             for dpid in flow.keys():
   33                 dp_id = dpid
   34                 switchnum= '{1}'.format(hex(int(dp_id)), int(dp_id))        
   35                 print('s'+switchnum,end = " ")
   36                 switchnum = int(switchnum)
   37             for list_table in flow.values():
   38                 for table in list_table:          
   39                     string1 = str(table)
   40                     if re.search("'dl_vlan': '(.*?)'", string1) is not None:
   41                        num = re.search("'dl_vlan': '(.*?)'", string1).group(1);
   42                        if num == '0' and switchnum == 1:
   43                           print('h1',end = " ")
   44                        if num == '1' and switchnum == 1:
   45                           print('h2',end = " ")
   46                        if num == '0' and switchnum == 2:
   47                           print('h3',end = " ")
   48                        if num == '1' and switchnum == 2:
   49                           print('h4',end = " ")
   50         print("")
   51         flow_list = self.getflow()
   52         for flow in flow_list:
   53             for dpid in flow.keys():
   54                 dp_id = dpid
   55                 print('switch_name:s{1}'.format(hex(int(dp_id)), int(dp_id)))
   56             for list_table in flow.values():
   57                 for table in list_table:
   58                     print(table)
   59 s1 = GetNodes("127.0.0.1:8080")
   60 s1.show()

   

（三）实验小结 在利用curl命令删除流表时，需要使用sudo apt install curl安装才可以使用，还有就是编写Python程序生成拓扑时，命令一直错误，后面发现是创建指令没有写完整的程序名。同时也复习了关于Ryu的运行方面的操作命令，以及关于.sh脚本的命令。ryu实验中创建的拓扑无法连接上控制器，需要使用命令ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest打开Ryu控制器。

标签：__,..,url,flow,REST,switch,API,table,id
From： https://www.cnblogs.com/vghf/p/16853180.html