实验7:基于REST API的SDN北向应用实践

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;
    img

    构建拓扑并连接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
    
    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)
    

    (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
    
    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("./flow.json") as f:
            jstr = f.read()
        headers = {'Content-Type': 'application/json'}
        res = requests.put(url, jstr, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
        print (res.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"
        }
      ]
    }
    

    flow.json文件

    结果如下图

    (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
  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/operational/opendaylight-inventory:nodes/node/openflow:1/flow-node-inventory:table/0/opendaylight-flow-table-statistics:flow-table-statistics'
      resp = http_get(url)
      print(resp.content)
  

结果如下

  1. Ryu

    运行Ryu

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

    (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
    
    if __name__ == "__main__":
        url = 'http://127.0.0.1:8080/stats/flowentry/add'
        with open("./ryu.json") as f:
            jstr = f.read()
        headers = {'Content-Type': 'application/json'}
        res = requests.post(url, jstr, headers=headers)
        print (res.content)
    
    

    ryu.json

    {
        "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
            }
        ]
     }
    

    执行结果

    (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。
    img

    构建拓扑:topo.py

    #!/usr/bin/env python
    from mininet.topo import Topo
    
    class MyTopo(Topo):
        def __init__(self):
            # initilaize topology
            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 = {'mytopo': (lambda: MyTopo())}
    

    (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。

    执行命令

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

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

    shell脚本 shell.sh

    # 将主机1,2发送来的数据包打上vlan标记
    curl -X POST -d '{
        "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
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
     curl -X POST -d '{
        "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
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
    # 将主机3,4发送来的数据包取出vlan标记
     curl -X POST -d '{
        "dpid": 1,
        "priority": 1,
        "match":{
            "vlan_vid": 0
        },
        "actions":[
            {
                "type": "POP_VLAN",    
                "ethertype": 33024       
            },
            {
                "type": "OUTPUT",
                "port": 1
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
     curl -X POST -d '{
        "dpid": 1,
        "priority": 1,
        "match":{
            "vlan_vid": 1
        },
        "actions":[
            {
                "type": "POP_VLAN",    
                "ethertype": 33024      
            },
            {
                "type": "OUTPUT",
                "port": 2
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
    # 将主机3,4发送来的数据包打上vlan标记
     curl -X POST -d '{
        "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
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
     curl -X POST -d '{
        "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
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
     curl -X POST -d '{
        "dpid": 2,
        "priority": 1,
        "match":{
            "vlan_vid": 0
        },
        "actions":[
            {
                "type": "POP_VLAN",    
                "ethertype": 33024      
            },
            {
                "type": "OUTPUT",
                "port": 1
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
     curl -X POST -d '{
        "dpid": 2,
        "priority": 1,
        "match":{
            "vlan_vid": 1
        },
        "actions":[
            {
                "type": "POP_VLAN",    
                "ethertype": 33024      
            },
            {
                "type": "OUTPUT",
                "port": 2
            }
        ]
     }' http://localhost:8080/stats/flowentry/add
    
    VLAN_ID Hosts
    0 h1 h3
    1 h2 h4

结果

(二)进阶要求

编程实现基本要求第2部分Ryu(3)中的VLAN划分。

fin.py

#!/usr/bin/python
import json

import requests

if __name__ == "__main__":
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    headers = {'Content-Type': 'application/json'}
    flow1 = {
        "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
            }
        ]
    }
    flow2 = {
        "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
            }
        ]
    }
    flow3 = {
        "dpid": 1,
        "priority": 1,
        "match":{
            "vlan_vid": 0
        },
        "actions":[
            {
                "type": "POP_VLAN",    
                "ethertype": 33024     
            },
            {
                "type": "OUTPUT",
                "port": 1
            }
        ]
    }
    flow4 = {
        "dpid": 1,
        "priority": 1,
        "match": {
            "vlan_vid": 1
        },
        "actions": [
            {
                "type": "POP_VLAN", 
                "ethertype": 33024  
            },
            {
                "type": "OUTPUT",
                "port": 2
            }
        ]
    }
    flow5 = {
        "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
            }
        ]
    }
    flow6 = {
        "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
            }
        ]
    }
    flow7 = {
        "dpid": 2,
        "priority": 1,
        "match": {
            "vlan_vid": 0
        },
        "actions": [
            {
                "type": "POP_VLAN", 
                "ethertype": 33024  
            },
            {
                "type": "OUTPUT",
                "port": 1
            }
        ]
    }
    flow8 = {
        "dpid": 2,
        "priority": 1,
        "match": {
            "vlan_vid": 1
        },
        "actions": [
            {
                "type": "POP_VLAN", 
                "ethertype": 33024  
            },
            {
                "type": "OUTPUT",
                "port": 2
            }
        ]
    }
    res1 = requests.post(url, json.dumps(flow1), headers=headers)
    res2 = requests.post(url, json.dumps(flow2), headers=headers)
    res3 = requests.post(url, json.dumps(flow3), headers=headers)
    res4 = requests.post(url, json.dumps(flow4), headers=headers)
    res5 = requests.post(url, json.dumps(flow5), headers=headers)
    res6 = requests.post(url, json.dumps(flow6), headers=headers)
    res7 = requests.post(url, json.dumps(flow7), headers=headers)
    res8 = requests.post(url, json.dumps(flow8), headers=headers)

(三)实验总结

3.1 实验难度:较大,实验涉及到OpenDaylight以及Ryu的使用,由于对它们使用的不够熟练,所以要重温之前的实验复习OpenDaylight以及Ryu的使用。

3.2 遇到的困难以及解决办法:

Q:

A:出现这种原因就是因为安装了多个版本的python,而且之前利用pip3 install requests给python3安装了requests模块,而python2.7没有安装requests模块,在终端输入 python 发现python配置的是2.7的环境变量,所以找不到requests模块。解决办法:将 python delete.py 改成 python3 delete.py

Q:

A:还未创建拓扑,应该先创建拓扑。

Q:

A:kill 掉占用端口号6633的程序
3.3 个人感想:通过实验复习了OpenDaylight以及Ryu的使用,学会编写程序调用OpenDaylight REST API实现特定网络功能以及学会编写程序调用Ryu REST API实现特定网络功能。

posted @ 2021-10-27 00:03  mingliangzi  阅读(3)  评论(0编辑  收藏  举报