实验7：基于REST API的SDN北向应用实践

一、实验目的

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

二、实验环境

下载虚拟机软件Oracle VisualBox或VMware；
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；

创建拓扑
sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
（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。
shanchu.py

#!/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)

执行python3 shanchu.py 由于之前并没有下发流表，所以产生提示：

（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('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": "flow1",
            "priority": "65535",
            "hard-timeout": "20",
            "cookie": "2",
            "table_id": "0"
        }
    ]
}

运行结果

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

运行结果

2.Ryu
在031902435目录下打开ryuryu-manager ryu/ryu/app/gui_topology/gui_topology.py --observe-links
（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。
ryuflow.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('ryu.json') as f:
        jstr = f.read()
    resp = http_post(url,jstr)
    print (resp.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
        }
    ]
 }

（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。

#!/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())}

构建拓扑
sudo mn --custom topo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

连接Ryu
ryu-manager ryu/ryu/app/gui_topology/gui_topology.py --observe-links

（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

shell 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

#!/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)

运行结果

四、个人总结

实验难度：难
这次实验相比之前的实验，用到的工具比较多。之前的实验在使用工具的过程中，或多或少都会出现一些问题，加上自己本身不够熟悉它们，所以这次实验遇到了很多问题，觉得实验难度会比较高一些。
实验过程中遇到的困难
- Q1：在做ryu相关部分实验时，出现报错OSError: [Errno 98] Address already in use
  A1：退出运行中的ODL
- Q2：基本要求的两个部分，都出现了ping不同的情况
  A2：回顾了之前的实验报告和自己的博客，发现创建拓扑和启动ODL、RYU的顺序错了。
- Q3：使用curl命令报错
  A3：要先开启RYU
- Q4：python xx.py文件时报错
  A4：使用python3即可
收获
通过这次实验掌握了编写程序调用OpenDaylight REST API、Ryu REST API实现特定网络功能，复习了ODL、Ryu的知识，命令的使用顺序真的很重要。经过前几次实验的锻炼，这次看官方文档会稍微顺利一些（还是离不开中文翻译器的辅助，要提高英文水平了[/汗颜]）。

posted @ 2021-10-26 17:34 八口八阅读(92) 评论(0) 编辑收藏举报

一只hyx

实验7：基于REST API的SDN北向应用实践

一、实验目的

二、实验环境

三、实验要求

（一）基本要求

（二）进阶要求

四、个人总结

公告