实验7:基于REST API的SDN北向应用实践
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
Ubuntu 20.04 Desktop amd64
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。
(2)下发指令删除s1上的流表数据。
delete.py
#!/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
#!/usr/bin/python#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
def http_put(url,jstr):
url= url
headers = {'Content-Type':'application/json'}
resp = requests.put(url,jstr,headers=headers,auth=HTTPBasicAuth('admin', 'admin'))
return resp
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 f:
jstr = f.read()
resp = http_put(url,jstr)
print (resp.content)
timeout.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"
}
]
}
(4) 获取s1上活动的流表数。
flow.py
#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
def http_get(url):
url= url
headers = {'Content-Type':'application/json'}
resp = requests.get(url,headers=headers,auth=HTTPBasicAuth('admin','admin'))
return resp
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 = http_get(url)
print(resp.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。
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
{
"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。
ryu-topo.py
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())}
ryu-shell.py
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": 1,
"priority": 1,
"match": {
"vlan_vid": 1
},
"actions": [
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 2
}
]
}
flow5 = {
"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
}
]
}
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": 0
},
"actions": [
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 1
}
]
}
flow8 = {
"dpid": 2,
"priority": 1,
"match": {
"vlan_vid": 1
},
"actions": [
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 2
}
]
}
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)
四、个人总结
这次的实验对我来说是很有难度的,我遇到了如下问题:1、编程问题,这个对我是最有难度的一环;2、基础部分1-1中,我ping通了,也有流表,但是在odl中好像并没有找到流表,运行删除流表的代码也是报错,报错问题是没有在路径中找到数据,我不知道是什么问题,百度和询问同学都没有找到解决办法;3、对有几步的具体操作流程,我不太清楚,后来是看同学的作业才知道具体的操作流程和顺序。这次的实验收获也主要是关于代码和ryu以及odl两个控制器的一些使用办法。