标签：__ url flow REST switch API SDN type requests

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.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；

生成topo

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

启动OpendDaylight

./distribution-karaf-0.4.4-Beryllium-SR4/bin/karaf

（2）下发指令删除s1上的流表数据。

delete.py

点击查看代码

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/'
    headers = {'Content-Type': 'application/json'}
    response = requests.delete(url=url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print(response.content)

运行结果

（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

点击查看代码

#!/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("./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

点击查看代码

{
    "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"
        }
    ]
    }

运行结果

（4）获取s1上活动的流表数。

get_flows.py

点击查看代码

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'}
    response = requests.get(url=url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print(response.content)

运行结果

2.编写Python程序，调用Ryu的北向接口实现以下功能

打开ryu

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

（1）实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。

ryu_timeout.py

点击查看代码

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

ryu_timeout.json

点击查看代码

{
    "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。
提示：拓扑生成后需连接Ryu，且Ryu应能够提供REST API服务
ryu_vlan.py

点击查看代码

import json
import requests

if __name__ == '__main__':
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    headers = {'Content-Type': 'application/json'}
    f = open('ryu_vlan.json').read()
    flows = json.loads(f)['flows']
    [requests.post(url, data=json.dumps(flows[i]), headers=headers) for i in range(0, 8)]

ryu_vlan.json

点击查看代码

{
	"flows": [
        {
			"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
				}
			]
		},
		{
			"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
				}
			]
		},
		{
			"dpid": 1,
			"priority": 1,
			"match": {
				"vlan_vid": 0
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 1
				}
			]
		},
		{
			"dpid": 1,
			"priority": 1,
			"match": {
				"vlan_vid": 1
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 2
				}
			]
		},
		{
			"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
				}
			]
		}, 
        {
			"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
				}
			]
		},
		{
			"dpid": 2,
			"priority": 1,
			"match": {
				"vlan_vid": 0
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 1
				}
			]
		},
		{
			"dpid": 2,
			"priority": 1,
			"match": {
				"vlan_vid": 1
			},
			"actions": [{
					"type": "POP_VLAN",
					"ethertype": 33024
				},
				{
					"type": "OUTPUT",
					"port": 2
				}
			]
		}
	]
}

下载curl

sudo apt install curl

topo连接控制器

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

删除流表

curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/1

curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/2

运行结果

（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。

getnodes.py

点击查看代码

import requests
import time
import re


class GetNodes:
    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 getflow(self):
        url = 'http://' + self.ip + '/stats/flow/%d'
        switch_list = self.get_switch_id()
        ret_flow = []
        for switch in switch_list:
            new_url = format(url % int(switch, 16))
            re_switch_flow = requests.get(url=new_url).json()
            ret_flow.append(re_switch_flow)
        return ret_flow

    def show(self):
        flow_list = self.getflow()
        for flow in flow_list:
            for dpid in flow.keys():
                dp_id = dpid
                switchnum= '{1}'.format(hex(int(dp_id)), int(dp_id))        
                print('s'+switchnum,end = " ")
                switchnum = int(switchnum)
            for list_table in flow.values():
                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',end = " ")
                       if num == '1' and switchnum == 1:
                          print('h2',end = " ")
                       if num == '0' and switchnum == 2:
                          print('h3',end = " ")
                       if num == '1' and switchnum == 2:
                          print('h4',end = " ")
        print("")
        flow_list = self.getflow()
        for flow in flow_list:
            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)
s1 = GetNodes("127.0.0.1:8080")
s1.show()

运行结果

(三)实验心得

这次实验比以往都难很多，我对其他人的代码做了很多参考才完成的，我在这次实验上做得仍不够好，代码上也还有很多没理解，我之后还要花时间在好好补一补，更好的理解代码的含义。
通过这实验，我对ODL和ryu都有了更深的理解，但也还有很多的不理解，需要更加的努力

标签：__,url,flow,REST,switch,API,SDN,type,requests
From： https://www.cnblogs.com/chenyanzhen/p/16853575.html

SDN 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

二、实验环境

三、实验要求

（一）基本要求

（二）进阶要求

(三)实验心得

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