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;
-
搭建拓扑:
sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
-
连接ODL:
./distribution-karaf-0.4.4-Beryllium-SR4/bin/karaf
(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。
- 建文件
sudo touch delete.py
#!/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。
- 建文件
sudo touch 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('timeout.json') as f:
jstr = f.read()
resp = http_put(url,jstr)
print (resp.content)
- 建文件
sudo touch 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) 编写Python程序,调用OpenDaylight的北向接口获取s1上活动的流表数。
- 建文件
sudo touch get.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.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。
启动RYU控制器:ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest
- 建文件
sudo touch put1.py
#!/usr/bin/python
import requests
if __name__ == "__main__":
url = 'http://127.0.0.1:8080/stats/flowentry/add'
with open("timeout1.json") as f:
jstr = f.read()
headers = {'Content-Type': 'application/json'}
res = requests.post(url, jstr, headers=headers)
print (res.content)
- 建文件
sudo touch timeout1.json
{
"dpid": 1,
"cookie": 1,
"cookie_mask": 1,
"table_id": 0,
"hard_timeout": 20,
"priority": 65535,
"flags": 1,
"match":{
"in_port":1
},
"actions":[
]
}
(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。
- 建文件
sudo touch topo.py
#!/usr/bin/env python
from mininet.topo import Topo
class MyTopo(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 = {'mytopo': (lambda: MyTopo())}
- 搭建拓扑:
sudo mn --custom topo.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 |
- 建文件
sudo touch 102192111sh.sh
- shell脚本
# 将主机1,2发送来的数据包打上vlan标记
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
# 将主机3,4发送来的数据包取出vlan标记
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
# 将主机3,4发送来的数据包打上vlan标记
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:
curl -X DELETE http://localhost:8080/stats/flowentry/clear/1
curl -X DELETE http://localhost:8080/stats/flowentry/clear/2
-
运行shell文件:
sh 102192111sh.sh
(二)进阶要求
编程实现基本要求第2部分Ryu(3)中的VLAN划分。
#!/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": 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
}
]
}
flow5 = {
"dpid": 1,
"priority": 1,
"match": {
"vlan_vid": 1
},
"actions": [
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 2
}
]
}
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": 1
},
"actions": [
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 2
}
]
}
flow8 = {
"dpid": 2,
"priority": 1,
"match": {
"vlan_vid": 0
},
"actions": [
{
"type": "POP_VLAN",
"ethertype": 33024
},
{
"type": "OUTPUT",
"port": 1
}
]
}
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
- 实验难度:难
- 实验过程遇到的困难及解决办法:
1、在进行利用curl命令进行实现的时候,当运行shell文件以后,pingall没变化,且显示curl有问题。如图所示,无法访问。
于是就查找其他同学的总结,看是否有解答,发现需要用命令删除流表,于是便执行curl命令去删除,显示未安装curl,然后便按照提示安装,之后进行流表删除,然后运行shell文件,发现再pingall以后,进行了VLAN划分,显然问题已解决,就是不知道是没安装curl的问题,还是没删除流表的问题,我个人认为是没安装,或许安装完以后没删除也会出现问题,但是我是直接删除的,所以没报错。
2、此外遇到的问题,就是在进阶要求里面,运行文件以后,再pingall,显示h2和h4没有ping上,当时不太明白是什么原因,当我把代码书写格式改了改以后,就又可以了,个人认为是代码没对应好,因为报错显示有“^”。
3、一开始进行中断时,用h1 ping h2,结果不行,中断无反应,看了别人的才发现要用h1 ping h3,成功解决。 - 个人感想:本次实验难度较大,遇到了不少问题,特别是一开始思考怎么去用程序来调用北向接口,后面自己尝试了以后明白了应该要打开控制器,然后搭建拓扑,最后运行程序,然后就可以实现用程序调用北向接口了。此外,在这次实验中,我通过尝试编写程序实现删除流表数据、下发硬超时流表和获取s1上活动的流表数,通过python编程来调用ODL和RYU的北向接口实现部分功能,使我对于如何使用编程的方法来调用北向接口有了更深的了解。本次实验我也了解到了如何用curl来删除流表,这边特别要注意的是,每次都要删除流表。也了解了SHELL文件如何运行。