实验7:基于REST API的SDN北向应用实践

一、实验目的

  • 能够编写程序调用OpenDaylight REST API实现特定网络功能;
  • 能够编写程序调用Ryu REST API实现特定网络功能。

二、实验环境

  • 下载虚拟机软件Oracle VisualBox或VMware;
  • .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;

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

(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。

  • del.py 代码
import requests
from requests.auth import HTTPBasicAuth
def del_table(url):
    headers = {'Content-Type' : 'application/json'}
    return requests.delete(url, headers = headers, auth=HTTPBasicAuth('admin', 'admin'))

if __name__ == "__main__":
    url= 'http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/'
    res = del_table(url)
    print (res.content)
- 执行结果:



(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

  • delay_table.py
import requests
from requests.auth import HTTPBasicAuth

def delay_flowtable(url, jstr):
    headers = {'Content-Type':'application/json'}
    return requests.put(url, jstr, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))

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('./flowtable1.json') as f:
        jstr = f.read()
    resp = delay_flowtable(url,jstr)
    print (resp.content)
  • tableflow1.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"
    }
  ]
}
- 执行结果




(4)编写Python程序,调用OpenDaylight的北向接口获取s1上活动的流表数

  • 代码
import requests
from requests.auth import HTTPBasicAuth
def get_table(url):
    headers = {'Content-Type':'application/json'}
    return requests.get(url,headers=headers,auth=HTTPBasicAuth('admin','admin'))

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'
    resp = get_table(url)
    print(resp.content)
- 运行结果



(二) 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

  • 代码
#!/usr/bin/python
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)
  • flowtable2.json
{
    "dpid": 1,
    "cookie": 1,
    "cookie_mask": 1,
    "table_id": 0,
    "hard_timeout": 20,
    "priority": 65535,
    "flags": 1,
    "match":{
        "in_port":1
    },
    "actions":[

    ]
 }
- 运行结果



(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

  • 生成的topo.py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())}
- 连接ryu控制器 ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest
  • 命令行输入以下命令创建拓扑:
    sudo sudo mn --custom topo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

  • 创建结果


(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
1 h2,h4
  • Shell脚本
# 将主机1,2发送来的包打上vlan标记</font>
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

<font size=4>
# 将主机3,4发送来的包取出vlan标记</font>
 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
</br>
# 将主机3,4发送来的包打上vlan标记
 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
- 执行结果



四 进阶要求

编程实现基本要求第2部分Ryu(3)中的VLAN划分

  • 代码
#!/usr/bin/python
import json

import requests

if __name__ == "__main__":
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    headers = {'Content-Type': 'application/json'}
    flow1 = {
        "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
            }
        ]
    }
    flow2 = {
        "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
            }
        ]
    }
    flow3 = {
        "dpid": 1,
        "priority": 1,
        "match":{
            "vlan_vid": 0
        },
        "actions":[
            {
                "type": "POP_VLAN",    
                "ethertype": 33024     
            },
            {
                "type": "OUTPUT",
                "port": 1
            }
        ]
    }
    flow4 = {
        "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
            }
        ]
    }
    flow5 = {
        "dpid": 1,
        "priority": 1,
        "match": {
            "vlan_vid": 1
        },
        "actions": [
            {
                "type": "POP_VLAN", 
                "ethertype": 33024  
            },
            {
                "type": "OUTPUT",
                "port": 2
            }
        ]
    }
    flow6 = {
        "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
            }
        ]
    }
    flow7 = {
        "dpid": 2,
        "priority": 1,
        "match": {
            "vlan_vid": 1
        },
        "actions": [
            {
                "type": "POP_VLAN", 
                "ethertype": 33024  
            },
            {
                "type": "OUTPUT",
                "port": 2
            }
        ]
    }
    flow8 = {
        "dpid": 2,
        "priority": 1,
        "match": {
            "vlan_vid": 0
        },
        "actions": [
            {
                "type": "POP_VLAN", 
                "ethertype": 33024  
            },
            {
                "type": "OUTPUT",
                "port": 1
            }
        ]
    }
    res1 = requests.post(url, json.dumps(flow1), headers=headers)
    res2 = requests.post(url, json.dumps(flow2), headers=headers)
    res3 = requests.post(url, json.dumps(flow3), headers=headers)
    res4 = requests.post(url, json.dumps(flow4), headers=headers)
    res5 = requests.post(url, json.dumps(flow5), headers=headers)
    res6 = requests.post(url, json.dumps(flow6), headers=headers)
    res7 = requests.post(url, json.dumps(flow7), headers=headers)
    res8 = requests.post(url, json.dumps(flow8), headers=headers)
- 运行结果


五、个人总结

  • 难度评价
    本次作业实验我感觉内容有点多,存在一定的难度,主要在阅读代码和文档上面。参考了同学优秀的博客,受到很多启发,同时也感觉到自己还是太菜了,特此感谢同学的帮助。


  • 实验过程遇到的困难及解决办法:

    1.连接拓扑后,一直无法ping通,导致作业卡顿了很久,同学的一句话点醒了我,原来是没有控制器,也就是ryu控制器没有连接。把ryu控制连接后,顺利ping通。(太低级了错误属实丢人)
    2.在进行ryu的第三个步骤实验时候,应该先把原流表删除,在用运行shell程序。
    3.openflow版本,习惯性的写上1.0版本。导致无法ping通现象,问了同学,改成openflow1.3,顺利解决


  • 个人感想

    做完作业,自信心有点受崩,可能这段时期状态也不是很好,一直在一些小细节上出问题,导致实验停滞,完成时间不断后拖。同学懂得很多也很优秀,希望自己慢慢能努力能向他们看齐。本次实验加深了自己对sdn三层体系架构的理解。通过调用北向接口的api,使得我在控制器管理,编程控制有了新的掌握。
posted @ 2021-10-27 14:20  朝如青丝暮成雪6  阅读(83)  评论(0编辑  收藏  举报