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
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；
新建拓扑图
sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
启动OpenDaylight
./distribution-karaf-0.6.4-Carbon/bin/karaf
在浏览器访问http://127.0.0.1:8181/index.html
（2） 下发指令删除s1上的流表数据
delete.py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/'
headers = {'Content-Type': 'application/json'}
res = requests.delete(url, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
print (res.content)
（3） 下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。
timeOut.py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)
（4） 获取s1上活动的流表数。
get.py代码：
#!/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)
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。
sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
(2)运行ryu：
ryu-manager ryu/ryu/app/ofctl_rest.py ryu/ryu/app/simple_switch_13.py
ryu_timeOut.py代码：
# ryu_timeout.py
import requests
if __name__ == "__main__":
url = 'http://127.0.0.1:8080/stats/flowentry/add'
with open("./ryu_timeOut.json") as file:
str = file.read()
headers = {'Content-Type': 'application/json'}
res = requests.post(url, str, headers=headers)
print (res.content)
ryu_timeOut.json代码：
# ryu_timeout.json
{
"dpid": 1,
"cookie": 1,
"cookie_mask": 1,
"table_id": 0,
"hard_timeout": 20,
"priority": 65535,
"flags": 1,
"match":{
"in_port":1
},
"actions":[
]
}
（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 | Hosts |
|---|---|
| 0 | h1 h3 |
| 1 | h2 h4 |
创建拓扑图
sudo mn --custom mytopo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
拓扑代码mytopo.py
#!/usr/bin/env python
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())}
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
shell.sh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
（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。
GetNode.py
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()
（三）实验小结
本次实验难度较大，在python3 delete.py的时候总是出错，后面改成sudo python3 delete.py才能运行成功；在下发硬超时流表，实现拓扑内主机h1和h3网络中断20s的时候，ping出来的时间总是重复4次，反复执行还是失败，后来重启虚拟机才能成功执行下去；ryu一直运行不出来，后来无意间关闭OpenDaylight 控制器，就能成功运行；在整理shell脚本的时候，因为先删除流表再执行拓扑图总是出错，后面发现只要先建拓扑图，然后再删除流表才能成功；一些运行不通的代码加上sudo才能运行成功，一些已经操作结束的窗口要及时关闭，以防印象后面代码的操作运行。
标签：__,self,VLAN,flow,REST,API,SDN,type,id From： https://www.cnblogs.com/zyt1006/p/16852841.html