SDN实验7:基于REST API的SDN北向应用实践

SDN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。

三、实验要求

1.OpenDaylight

  • 利用Mininet平台搭建下图所示网络拓扑,并连接OpenDaylight
  • 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

删除流表代码

#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)
  • 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

下发流表的python代码

#puts.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("./ODL_flowtable.json") as f:
        jstr = f.read()
    headers = {'Content-Type': 'application/json'}
    res = requests.put(url, jstr, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print (res.content) 

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": "20",
      "cookie": "2",
      "table_id": "0"
    }
  ]
}

实现效果如下图:

获取流表信息的python代码

#gets.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)

运行效果如下图:

2.Ryu

  • 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

流表下发的python代码

import requests

if __name__ == "__main__":
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    with open("./flowtable.json") as f:
        jstr = f.read()
    headers = {'Content-Type': 'application/json'}
    res = requests.post(url, jstr, headers=headers)
    print (res.content)

flowtable.json

{
    "dpid": 1,
    "cookie": 1,
    "cookie_mask": 1,
    "table_id": 0,
    "hard_timeout": 20,
    "priority": 65535,
    "flags": 1,
    "match":{
        "in_port":1
    },
    "actions":[

    ]
 }

运行效果如下图:

  • 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
    • 搭建拓扑的python代码
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())}

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

  • 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

删除流表:

curl -X DELETE http://localhost:8080/stats/flowentry/clear/1
curl -X DELETE http://localhost:8080/stats/flowentry/clear/2

编写shell脚本

curl -X POST -d '{
    "dpid": 1,
    "priority": 1,
    "match":{
        "in_port": 1
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # Set VLAN ID
            "value": 4096            # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # Set VLAN ID
            "value": 4097            # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=4096)
        },
        {
            "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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # Set VLAN ID
            "value": 4096            # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # Set VLAN ID
            "value": 4097            # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=4096)
        },
        {
            "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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "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",     # Push a new VLAN tag if a input frame is non-VLAN-tagged
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

运行效果如下图:

四、实验总结:

  • 本次实验学会了odl和ryu的编程下发流表,查看流表,删除流表等操作,可以为接下来的sdn大作业做准备
  • 经过本次实验,通过自己编程来调用ODL的北向接口实现部分功能,使我对基于REST API的SDN北向应用有了深刻的认识
  • 进一步学习了python的request库,把原本快要遗忘的知识重新学习巩固了起来
posted @ 2021-10-27 00:18  说了那么多的晚安  阅读(23)  评论(0编辑  收藏  举报