实验7: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

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
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) 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('h_timeout.json') as f:
        jstr = f.read()
    resp = http_put(url,jstr)
    print (resp.content)
{
    "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
import json
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/config/opendaylight-inventory:nodes/node/openflow:1/flow-node-inventory:table/0'
    resp = http_get(url)
    res = json.loads(resp.text)
    # print(resp.text)
    print(len(res['flow-node-inventory:table'][0]['flow']))


注:delete.py之前已经执行过了,所以报错。

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
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_h_timeout.json') as f:
        jstr = f.read()
    resp = http_post(url,jstr)
    print (resp.content)
{
    "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
        }
    ]
 }

四、个人总结

本次实验倒是没有出现软件方面的问题,就是代码还是不太会改,基本上复制同学的。第二个ryu实验用的系统内置的simple_switch_13.py,

因为需要使用到ofctl_rest.py,所以要注意在ryu下的app文件夹打开终端,避免出现找不到目录的情况。每段代码中最后一段是json文件,因为
之前用postman直接写可视化界面上,一开始我还不知道写文件里。
这次实验操作是使用 python 向指定 url 发送请求来调用 REST API,用代码表示总的来说比之前可视化操作反而看起来清晰很多。

posted @ 2021-10-18 12:01  林枢  阅读(168)  评论(0编辑  收藏  举报