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；
- 使用命令
./distribution-karaf-0.6.4-Carbon/bin/karaf打开ODL控制器 - 使用命令
sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13创建拓扑并连接控制器
（2） 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） 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("./flowtimeout.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)json文件：
{ "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。
#!/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)
- 使用命令
-
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。
-
关闭ODL控制器，关闭上次的拓扑并清除拓扑后
-
使用命令
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest打开Ryu控制器 -
使用命令
sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13创建拓扑
#!/usr/bin/python import requests if __name__ == "__main__": url = 'http://127.0.0.1:8080/stats/flowentry/add' with open("./hardtimeout.json") as file: str = file.read() headers = {'Content-Type': 'application/json'} res = requests.post(url, str, headers=headers) print (res.content)json文件：
{ "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#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())}-
关闭控制器，关闭上一次实验的拓扑并清除拓扑
-
使用命令
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest打开Ryu控制器 -
使用命令
sudo mn --custom topo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13创建拓扑
-
| VLAN_ID | Hosts |
|---|---|
| 0 | h1 h3 |
| 1 | h2 h4 |
-
使用命令
-
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
-
删除流表
-
使用命令sh sh1.sh运行shell脚本
（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。
-
使用命令
-
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
-
删除流表
-
运行下述代码：
#!/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": 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
本次实验是对前两次的进阶，进一步考验通过编程来控制控制器的使用，总体难度较大，需要查阅API文档较多。
实验中遇到的问题及解决办法：
- 做VLAN划分时下发流表后还是全部都能互相ping通。
- 解决方法：应该先把所有流表删除在进行新流表的下发。
- 使用Ryu控制器时，发现创建拓扑后无法ping通。
- 解决方法：建立拓扑时应该使用OpenFlow1.3，使用OpenFlow1.0会出现无法ping通的情况
通过这次实验，进一步学习了用OpenDaylight和Ryu的rest API来实现特定的网络功能，除此之外还进一步学习了python的request库，为接下来做大作业打下了基础。同时在实验中遇到问题查看了相关文档，锻炼了阅读文档的能力。这次实验中是由几个小实验组成的，做完一个做下一个的时候，要记得把前一次的拓扑清空。实验中要记得先把流表清空。还有curl的下载，按照百度的方法利用wget来下载，下了好几次都不行，最后用命令行里的提示，利用命令sudo apt install curl才下载成功。
标签：__,REST,port,headers,json,API,SDN,type,requests From： https://www.cnblogs.com/mianmian7/p/16819059.html