实验7：基于REST API的SDN北向应用实践

标签：__ self VLAN flow REST API SDN ryu type

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、编写Python程序，调用OpenDaylight的北向接口实现以下功能
（1）利用Mininet平台搭建下图所示网络拓扑，并连接OpenDaylight；

启动ODL
./distribution-karaf-0.6.4-Carbon/bin/karaf
创建topo
sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

（2）下发指令删除s1上的流表数据。

编写delete.py，调用OpenDaylight的北向接口下发指令删除s1上的流表数据

delete.py

点击查看代码

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/'
    headers = {'Content-Type': 'application/json'}
    response = requests.delete(url=url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print(response.content)

（3）下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。

编写timeout.py及timeout.json，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

timeout.py

点击查看代码

#!/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("./timeout.json") as file:
        str = file.read()
    headers = {'Content-Type': 'application/json'}
    res = requests.put(url, str, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print (res.content)

timeout.json

点击查看代码

{
    "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": "flow",
        "priority": "65535",
        "hard-timeout": "20",
        "cookie": "2",
        "table_id": "0"
        }
    ]
    }

（4）获取s1上活动的流表数。

编写get_flows.py，调用OpenDaylight的北向接口获取s1上活动的流表数

get_flows.py

点击查看代码

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'}
    response = requests.get(url=url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
    print(response.content)

2、编写Python程序，调用Ryu的北向接口实现以下功能
（1）实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。

编写ryu_timeout.py及ryu_timeout.json，调用Ryu的北向接口实现硬超时流表下发

ryu_timeout.py

点击查看代码

import requests
from requests.auth import HTTPBasicAuth

if __name__ == '__main__':
    url = 'http://127.0.0.1:8080/stats/flowentry/add'
    headers = {'Content-Type': 'application/json'}
    json = open('ryu_timeout.json').read()
    response = requests.post(url, data=json, headers=headers)
    print(response.content)

ryu_timeout.json

点击查看代码

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

打开ryu
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest
创建topo
sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
运行ryu_timeout.py
实现硬超时功能

（2）参考Ryu REST API的文档，基于VLAN实验的网络拓扑，编程实现相同的VLAN配置。
提示：拓扑生成后需连接Ryu，且Ryu应能够提供REST API服务

VLAN_ID	HOST
0	h1、h3
1	h2、h4

根据VLAN实验的网络拓扑编写ryu_topo.py

ryu_topo.py

点击查看代码

from mininet.topo import Topo
 
class ryu_topo(Topo):
    def __init__(self):
        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 = {'ryu_topo': (lambda: ryu_topo())}

参考Ryu REST API的文档，编写ryu_shell.sh脚本

ryu_shell.sh

点击查看代码

# To set VLAN ID to non-VLAN-tagged frame（s1从1、2口收到h1、h2发来的包并打上vlan_tag,从3口转发)
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

#Pop the outer VLAN tag（ 将s1发回至h1、h2的包从1、2号端口脱掉vlan_tag)
curl -X POST -d '{
    "dpid": 1,
    "priority": 1,
    "match":{
        "vlan_vid": 0
    },
    "actions":[
        {
            "type": "POP_VLAN",     # Pop the outer VLAN tag
            "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",     # Pop the outer VLAN tag
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]
}' http://localhost:8080/stats/flowentry/add

# To set VLAN ID to non-VLAN-tagged frame（s2从1、2口收到h3、h4发来的包并打上vlan_tag,从3口转发)
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


#Pop the outer VLAN tag（ 将s2发回至h3、h4的包从1、2号端口脱掉vlan_tag)
curl -X POST -d '{
    "dpid": 2,
    "priority": 1,
    "match":{
        "vlan_vid": 0
    },
    "actions":[
        {
            "type": "POP_VLAN",     # Pop the outer VLAN tag
            "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",     # Pop the outer VLAN tag
            "ethertype": 33024       # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]
}' http://localhost:8080/stats/flowentry/add

打开ryu
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest
topo连接控制器
sudo mn --custom ryu_topo.py --topo ryu_topo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
删除流表
curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/1
curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/2
运行ryu_shell.sh脚本
实现相同的VLAN配置

(二）进阶要求
OpenDaylight或Ryu任选其一，编程实现查看前序VLAN实验拓扑中所有节点（含交换机、主机）的名称，以及显示每台交换机的所有流表项。

编写getnodes.py,实现查看节点信息

getnodes.py

点击查看代码

import requests
import time
import re


class GetNodes:
    def __init__(self, ip):
        self.ip = ip
        
    def get_switch_id(self):
        url = 'http://' + self.ip + '/stats/switches'
        re_switch_id = requests.get(url=url).json()
        switch_id_hex = []
        for i in re_switch_id:
            switch_id_hex.append(hex(i))

        return switch_id_hex

    def getflow(self):
        url = 'http://' + self.ip + '/stats/flow/%d'
        switch_list = self.get_switch_id()
        ret_flow = []
        for switch in switch_list:
            new_url = format(url % int(switch, 16))
            re_switch_flow = requests.get(url=new_url).json()
            ret_flow.append(re_switch_flow)
        return ret_flow

    def show(self):
        flow_list = self.getflow()
        for flow in flow_list:
            for dpid in flow.keys():
                dp_id = dpid
                switchnum= '{1}'.format(hex(int(dp_id)), int(dp_id))        
                print('s'+switchnum,end = " ")
                switchnum = int(switchnum)
            for list_table in flow.values():
                for table in list_table:          
                    string1 = str(table)
                    if re.search("'dl_vlan': '(.*?)'", string1) is not None:
                        num = re.search("'dl_vlan': '(.*?)'", string1).group(1);
                        if num == '0' and switchnum == 1:
                            print('h1',end = " ")
                        if num == '1' and switchnum == 1:
                            print('h2',end = " ")
                        if num == '0' and switchnum == 2:
                            print('h3',end = " ")
                        if num == '1' and switchnum == 2:
                            print('h4',end = " ")
        print("")
        flow_list = self.getflow()
        for flow in flow_list:
            for dpid in flow.keys():
                dp_id = dpid
                print('switch_name:s{1}'.format(hex(int(dp_id)), int(dp_id)))
            for list_table in flow.values():
                for table in list_table:
                    print(table)
s1 = GetNodes("127.0.0.1:8080")
s1.show()

基于（一）2，运行getnodes.py进行查看

三、个人感想
1、本次实验需要不断查阅文档资料，进一步学习到了ODL REST API和Ryu REST API的使用，进一步学习到了ODL和Ryu北向接口的使用。基础部分结合了前面做过的实验，也是对前面做过实验的复习，使各个实验联结在一起，使各个知识点更好的融合在一个实验中体现出来，收获颇多。进阶部分对编程要求较高，本人编程能力比较薄弱，此部分参考其他同学的代码而实现，也认真地研究其代码实现的思想，收获颇多！
2、参考Ryu REST API的文档
https://ryu.readthedocs.io/en/latest/app/ofctl_rest.html详见Update the switch stats一节

3、问题及解决
1）
问题：划分VLAN实验中，运行完ryu_shell.sh脚本依旧ping全通

解决：下发删除流表

2）
问题：curl拒绝连接

解决：发现ryu控制器被我误关了，打开ryu控制器即可

标签：__,self,VLAN,flow,REST,API,SDN,ryu,type
From： https://www.cnblogs.com/99Sina-Lee/p/16839932.html

实验7：基于REST API的SDN北向应用实践

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