实验7：基于REST API的SDN北向应用实践

标签：__ url REST headers json API SDN type requests

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.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；

- 构建拓扑

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

启动OpenDaylight 控制器

连接OpenDaylight

sudo mn --topo=single,3 --mac --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。

#!/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）下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。

timeout.py

#!/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("./timeout.json") as f:
		jstr = f.read()
	resp = http_put(url,jstr)
	print (resp.content)

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"
    }
  ]
}

执行结果截图

（4）获取s1上活动的流表数。

getflow.py

#!/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)

执行结果截图

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。

ryu_timeout.py

#!/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("./timeout_ryu.json") as f:
		jstr = f.read()
	resp = http_post(url,jstr)
	print (resp.content)

ryu_timeout.json

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

    ]
}

启动ryu控制器

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

-执行结果截图

（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

VLAN_ID	Hosts
0	h1h3
1	h1h4

ryu_topo.py

from mininet.topo import Topo

class MyTopo(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 = {'mytopo': (lambda: MyTopo())}

ryu_vlan.py

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)

构建拓扑

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

连接Ryu，需要同时开启REST API和运行一个支持OpenFlow 1.3的交换机命令

ryu-manager ryu/ryu/app/ofctl_rest.py ryu/ryu/app/simple_switch_13.py

删除流表

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

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

执行结果

（二）个人总结

通过此次实验对ryu和OpenDaylight的运用有了更深刻的理解，对于自己的编程能力仍需努力
通过此次实验我发现自己需要学习的东西还有很多，知识点只会越挖越多，越挖越深刻
此次实验建立在了之前实验的基础上，所以运行时不会有太多的问题
在删除流表时遇到问题，安装相应插件即可，命令：sudo snap install curl

标签：__,url,REST,headers,json,API,SDN,type,requests
From： https://www.cnblogs.com/ll520/p/16887823.html

实验7：基于REST API的SDN北向应用实践

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