实验7：基于REST API的SDN北向应用实践

一、实验目的

1. 能够编写程序调用OpenDaylight REST API实现特定网络功能；
2. 能够编写程序调用Ryu REST API实现特定网络功能。

二、实验环境

1. 下载虚拟机软件Oracle VisualBox或VMware；
2. 在虚拟机中安装Ubuntu 20.04 Desktop amd64，并完整安装Mininet、OpenDaylight（Carbon版本）、Postman和Ryu；

三、实验要求

（一）基本要求

1. OpenDaylight

   （1） 利用Mininet平台搭建下图所示网络拓扑，并连接OpenDaylight；

   

（2) 编写Python程序，调用OpenDaylight的北向接口下发指令删除s1上的流表数据。

#!/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） 编写Python程序，调用OpenDaylight的北向接口下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。

#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
def http_put(url,jstr):
    url= url
    headers = {'Content-Type':'application/json'}
    resp = requests.put(url,jstr,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/flow-node-inventory:table/0/flow/1'
    with open('h_timeout.json') as f:
        jstr = f.read()
    resp = http_put(url,jstr)
    print (resp.content)
{
    "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": "flow1",
            "priority": "65535",
            "hard-timeout": "20",
            "cookie": "2",
            "table_id": "0"
        }
    ]
}

（4) 编写Python程序，调用OpenDaylight的北向接口获取s1上活动的流表数。

  #！/usr/bin/python
  import requests
  import json
  from requests.auth import HTTPBasicAuth
  def http_get(url):
      url= url
      headers = {'Content-Type':'application/json'}
      resp = requests.get(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/flow-node-inventory:table/0'
      resp = http_get(url)
      res = json.loads(resp.text)
      # print(resp.text)
      print(len(res['flow-node-inventory:table'][0]['flow']))

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

   #!/usr/bin/python
   import requests
   from requests.auth import HTTPBasicAuth
   def http_post(url,jstr):
       url= url
       headers = {'Content-Type':'application/json'}
       resp = requests.post(url,jstr,headers=headers)
       return resp
   
   if __name__ == "__main__":
       url='http://127.0.0.1:8080/stats/flowentry/add'
       with open('ryu_htimeout.json') as f:
           jstr = f.read()
       resp = http_post(url,jstr)
       print (resp.content)
   {
       "dpid": 1,
       "cookie": 1,
       "cookie_mask": 1,
       "table_id": 0,
       "hard_timeout": 20,
       "priority": 65535,
       "flags": 1,
       "match":{
           "in_port":1
       },
       "actions":[
           {
               "type":"OUTPUT",
               "port": 2
           }
       ]
    }

3. （2） 利用Mininet平台搭建下图所示网络拓扑，要求支持OpenFlow 1.3协议，主机名、交换机名以及端口对应正确。拓扑生成后需连接Ryu，且Ryu应能够提供REST API服务。
   

   

   

   

   （3) 整理一个Shell脚本，参考Ryu REST API的文档，利用curl命令，实现和实验2相同的VLAN。

   VLAN_ID	Hosts
   0	h1 h3
   1	h2 h4

4. 心得体会
5. 好多都是不会做，上节课因为有事请假也是没有去上课，做实验的时候也是一脸懵，感觉好难的样子，后面也是没有做出来，提取了大部分同学的代码，也请教了许多人。