实验7：基于REST API的SDN北向应用实践

标签：__ url self flow REST headers API SDN requests

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
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；

（2）下发指令删除s1上的流表数据。

点击查看代码

# delete.py
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）下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。

点击查看代码

# timeout.py
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("./timeout.json") as file:
        str = file.read()
    headers = {'Content-Type': 'application/json'}
    res = requests.put(url, str, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print (res.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"
      }
    ]
  }

（4）获取s1上活动的流表数。

点击查看代码

# getflow.py
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)

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。

点击查看代码

# ryu_timeout.py
import requests
if __name__ == "__main__":
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    with open("./ryu_timeout.json") as file:
        str = file.read()
    headers = {'Content-Type': 'application/json'}
    res = requests.post(url, str, headers=headers)
    print (res.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":[

    ]
 }

（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。

点击查看代码

# ryu_topo.py
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())}
# 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)

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 h1 h3
1 h2 h4
（二）进阶要求
OpenDaylight或Ryu任选其一，编程实现查看前序VLAN实验拓扑中所有节点（含交换机、主机）的名称，以及显示每台交换机的所有流表项。

点击查看代码

import requests
import time
import re


class GetInformation:
    def __init__(self, ip):
        self.ip = ip
        

    def get_switch_id(self):
        url = 'http://' + self.ip + '/stats/switches'
        re_switch_id = requests.get(url=url).json()
        switch_id_hex = []
        for i in re_switch_id:
            switch_id_hex.append(hex(i))

        return switch_id_hex

    def get_flow_table(self):
        url = 'http://' + self.ip + '/stats/flow/%d'
        list_switch = self.get_switch_id()
        all_flow = []
        for switch in list_switch:
            new_url = format(url % int(switch, 16))
            re_switch_flow = requests.get(url=new_url).json()
            all_flow.append(re_switch_flow)

        return all_flow

    def show_flow(self):
        list_flow = self.get_flow_table()
        for flow in list_flow:
            for dpid in flow.keys():
                dp_id = dpid
                print('switch_name:s{1}'.format(hex(int(dp_id)), int(dp_id)))
            for list_table in flow.values():
                for table in list_table:
                    print(table)
    def show_name(self):
    	
        list_flow = self.get_flow_table()
        for flow in list_flow:
            for dpid in flow.keys():
                dp_id = dpid
                switchnum= '{1}'.format(hex(int(dp_id)), int(dp_id))        
                print('s'+switchnum)
                switchnum = int(switchnum)
            for list_table in flow.values():
                count = 0
                for table in list_table:
                  
                    string1 = str(table)
                    
                    if re.search("'dl_vlan': '(.*?)'", string1) is not None:
                       num = re.search("'dl_vlan': '(.*?)'", string1).group(1);
                       if num == '0' and switchnum == 1:
                          print('h1')
                       if num == '1' and switchnum == 1:
                          print('h2')
                       if num == '0' and switchnum == 2:
                          print('h3')
                       if num == '1' and switchnum == 2:
                          print('h4')

S1 = GetInformation("127.0.0.1:8080");
S1.show_name();
S1.show_flow();

（三）实验报告个人总结，包括但不限于实验难度、实验过程遇到的困难及解决办法，个人感想，不少于200字。

太难了，没做过这么难的额，要记得输入命令sudo apt install curl下载curl之后再对RYU控制器进行删除流表操作。在打开ODL做完实验之后要记得关闭确保在做RYU部分可以整成运行，并且RYU要一直开着。
本次实验学习了如何编写程序调用DSL REST API实现特定网络功能,如何编写程序调用Ryu REST API实现特定网络功能，对基于REST API的SDN北向应用有了更加深刻的了解，并熟悉对于这些常用控制器RYU,ODL的使用，本次实验内容较多，对我来说难度还是比较大，在阅读代码和文档上面比较困难。但是经过不断的修改并参考同学的博客也懂得了很多

标签：__,url,self,flow,REST,headers,API,SDN,requests
From： https://www.cnblogs.com/nmb123456/p/16846252.html

实验7：基于REST API的SDN北向应用实践

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