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
    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("./flowtable.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)
flowtable.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": "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
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)

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

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

(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。

  • 搭建拓补如下

  • 拓补文件代码

      #!/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。

VLAN_ID Hosts
0 h1 h3
1 h2 h4


shellryu.sh脚本
  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

   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

   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

(二)进阶要求

编程实现基本要求第2部分Ryu(3)中的VLAN划分。

#!/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)

四、个人总结

  • 本次实验难度偏难,需要综合过去对于OpenDayLight和Ryu实验的操作方法,加上本次实验需要编写代码文件对流表项进行对应的删除,更新下发流表,获取流表数的操作,需要许多值得注意的细节,特别是需要分别用ODL和Ryu实现,就需要对两类北向接口的文档做详细的学习,在本次实验进行更深一步的理解与实践,本次实验很多内容都借鉴的相关参考,按照已有的实验结果进行反推构思,这样做很大一部分原因是为了缓解学习的困难,但是同样也降低了学习验收效果,用Python编程调用接口的方法还需进一步学习。
posted on 2021-10-27 12:29  natsu。  阅读(5)  评论(0编辑  收藏  举报