一、實驗目的

對 Python 呼叫 OpenDaylight 的 REST API 方法有初步瞭解。

二、實驗任務

本實驗需要用另一種方法完成上一個實驗相同的功能,即通過 Python 程式呼叫OpenDaylight 的北向介面下發關於硬超時的流表,實現拓撲內主機在一定時間內的網路通斷。實驗拓撲如下:

三、實驗步驟

1. 實驗環境
   安裝了 Ubuntu 18.04.5 Desktop amd64 的虛擬機器
2. 實驗過程
   (1)啟動OpenDaylight
   
   (2)清理舊資料
   
   (3)生成拓撲

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

(4)編寫Python程式碼和Json格式的請求內容

vim odlnorth.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('hardtimeout.json') as f:
        jstr = f.read()
    resp = http_put(url,jstr)
    print resp.content
 

vim hardtimeout.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": "10",
            "cookie": "2",
            "table_id": "0"
        }
    ]
}
 

(5)執行 Python 程式碼,完成流表下發

$ python odlnorth.py