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
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.OpenDaylight
(1) 利用Mininet平台搭建下图所示网络拓扑,并连接OpenDaylight;
- 输入命令打开ODL控制器
./distribution-karaf-0.6.4-Carbon/bin/karaf
- 输入命令创建拓扑,并连接控制器(输入网址:http://127.0.0.1:8181/index.html)
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。
#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
def http_delete(url):
url= url
headers = {'Content-Type':'application/json'}
resp = requests.delete(url, 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/'
resp = http_delete(url)
print(resp.content)
(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。
- put.py
#!/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('flowtable.json') as f:
jstr = f.read()
resp = http_put(url,jstr)
print (resp.content)
- flowtable.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"
}
]
}
- 运行结果
(4) 编写Python程序,调用OpenDaylight的北向接口获取s1上活动的流表数。
#!/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.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。
- ryuflow.py
#!/usr/bin/python
import requests
from requests.auth import HTTPBasicAuth
def http_post(url,jstr):
url= url
headers = {'Content-Type':'application/json'}
resp = requests.post(url,jstr,headers=headers)
return resp
if __name__ == "__main__":
url='http://127.0.0.1:8080/stats/flowentry/add'
with open('ryuflow.json') as f:
jstr = f.read()
resp = http_post(url,jstr)
print (resp.content)
- ryuflow.json
{
"dpid": 1,
"cookie": 1,
"cookie_mask": 1,
"table_id": 0,
"hard_timeout": 20,
"priority": 65535,
"flags": 1,
"match":{
"in_port":1
},
"actions":[
{
"type":"OUTPUT",
"port": 2
}
]
}
(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。
- 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())}
- 运行拓扑
sudo mn --custom mytopo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
(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
curl -X POST -d '{
"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
}
]
}' http://localhost:8080/stats/flowentry/add
curl -X POST -d '{
"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
}
]
}' http://localhost:8080/stats/flowentry/add
curl -X POST -d '{
"dpid": 1,
"priority": 1,
"match":{
"vlan_vid": 0
},
"actions":[
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"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",
"ethertype": 33024
},
{
"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",
"ethertype": 33024
},
{
"type": "SET_FIELD",
"field": "vlan_vid",
"value": 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",
"ethertype": 33024
},
{
"type": "SET_FIELD",
"field": "vlan_vid",
"value": 4097
},
{
"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",
"ethertype": 33024
},
{
"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",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 2
}
]
}' http://localhost:8080/stats/flowentry/add
-
删除流表
-
运行结果
(二)进阶要求
编程实现基本要求第2部分Ryu(3)中的VLAN划分。
(三)实验报告
1.请用Markdown排版;
2.将所有本实验相关文件保存在目录/home/用户名/学号/lab7/中;
3.(一)只需要提交实现相应Python代码和执行结果截图,其余文字请勿赘述;
4.(二)不做必须要求,有完成的同学请提交Python代码和运行结果,文件保存目录参照要求2。
5.个人总结,包括但不限于实验难度、实验过程遇到的困难及解决办法,个人感想,不少于200字。
- 本次实验难度不算太难,主要是有前面几次实验的基础,在理解控制器使用的基础上,结合python代码进行命令调用。比较难的在于命令代码的书写,这个在老师提供pdf的基础上,也参考了其他同学的代码,才算顺利解决。
- 这次的实验代码比较多,由于笔记本的键盘比较小,之前设置双向无法顺利退出,于是无法直接将代码进行复制到虚拟机中。之前代码量比较少出现错误还比较好排查,但这次代码量比较多,排查起来效率就比较低。后面是借用同学的笔记本再操作了一遍。整体上了解操作的思路,还较为顺利。
- 在实验过程中,控制器的连接是否成功需要注意已经成功连接,注意命令的使用要求。连接成功后,pingall有时候会出现一定的延迟,可以稍等会儿再pingall一次,如果还是不行,那最好再返回去检查确认清楚控制器有无连接好。
- 这次的实验,令我更进一步了解了控制器的功能和使用,但是在代码方面相对还是比较薄弱,除了基础的命令外,大部分要靠参考别人的作业,来作为理解的途径之一。