SDN第七次上机实验

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

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） 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

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("./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)

（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
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)

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。

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('flowtable2.json') as f:
        jstr = f.read()
    resp = http_post(url,jstr)
    print (resp.content)

（2） 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。

（3) 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。

VLAN_ID	Hosts
0	h1 h3

curl -X POST -d '{
  "dpid": 1,
  "match": {
    "in_port": 1
  },
  "actions": [
    {
      "type": "PUSH_VLAN",
      "ethertype": 33024
    },
    {
      "type": "SET_FIELD",
      "field": "vlan_vid",
      "value": 4096
    },
    {
      "type":"OUTPUT",
      "port": 3
    }
    ],
    "priority":5
}' http://localhost:8080/stats/flowentry/add

curl -X POST -d '
{
  "dpid": 1,
  "priority":5,
  "match": {
    "in_port": 2
  },
  "actions": [
    {
      "type": "PUSH_VLAN",
      "ethertype": 33024
    },
    {
      "type": "SET_FIELD",
      "field": "vlan_vid",
      "value": 4097
    },
    {
      "type":"OUTPUT",
      "port": 3
    }
    ]
}' http://localhost:8080/stats/flowentry/add

curl -X POST -d '
{
  "dpid": 1,
  "match": {
    "vlan_vid": 0
  },
  "actions": [
    {
      "type": "POP_VLAN",
      "ethertype": 33024
    },
    {
      "type":"OUTPUT",
      "port": 1
    }
    ],
    "priority":5
}
' http://localhost:8080/stats/flowentry/add

curl -X POST -d'
{
  "dpid": 1,
  "match": {
    "vlan_vid": 1
  },
  "actions": [
    {
      "type": "POP_VLAN",
      "ethertype": 33024
    },
    {
      "type":"OUTPUT",
      "port": 2
    }
    ],
    "priority":5
}
' http://localhost:8080/stats/flowentry/add
curl -X POST -d '{
  "dpid": 2,
  "match": {
    "in_port": 1
  },
  "actions": [
    {
      "type": "PUSH_VLAN",
      "ethertype": 33024
    },
    {
      "type": "SET_FIELD",
      "field": "vlan_vid",
      "value": 4096
    },
    {
      "type":"OUTPUT",
      "port": 3
    }
    ],
    "priority":5
}' http://localhost:8080/stats/flowentry/add

curl -X POST -d '
{
  "dpid": 2,
  "match": {
    "in_port": 2
  },
  "actions": [
    {
      "type": "PUSH_VLAN",
      "ethertype": 33024
    },
    {
      "type": "SET_FIELD",
      "field": "vlan_vid",
      "value": 4097
    },
    {
      "type":"OUTPUT",
      "port": 3
    }
    ],
    "priority":5
}' http://localhost:8080/stats/flowentry/add

curl -X POST -d '
{
  "dpid": 2,
  "match": {
    "vlan_vid": 0
  },
  "actions": [
    {
      "type": "POP_VLAN",
      "ethertype": 33024
    },
    {
      "type":"OUTPUT",
      "port": 1
    }
    ],
    "priority":5
}
' http://localhost:8080/stats/flowentry/add

curl -X POST -d'
{
  "dpid": 2,
  "match": {
    "vlan_vid": 1
  },
  "actions": [
    {
      "type": "POP_VLAN",
      "ethertype": 33024
    },
    {
      "type":"OUTPUT",
      "port": 2
    }
    ],
    "priority":5
}' http://localhost:8080/stats/flowentry/add

四、心得体会

通过几次的实验实操，对于虚拟机掌握就已经较为熟练，对于相应的课程知识也巩固的很不错。但是针对本次实验，还是有很多地方存在问题，首先不懂电脑原因还是虚拟机问题，实验过程中出现了多次死机。其次还是遇到了之前一样的问题，有时候不能进行复制。最后的话有几个实验步骤不是很能清楚地理解并且独立完成 ，通过请教的几名同学才得以最后搞定，还是感觉有一点点难度，不过自己也是会继续努力完成每次作业。