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
- 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
- OpenDaylight
（1） 利用Mininet平台搭建下图所示网络拓扑，并连接OpenDaylight；
（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。
删除流表代码delete.py
import requests
headers = {'Content-Type': 'application/json'}
def del_flowtable(url):
resp = requests.delete(url, headers=headers)
return resp
if name == "main":
url = "http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/"
resp = del_flowtable(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。
下发硬超时流表代码overtime.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/flow-node-inventory:table/0/flow/1' with open("./flowtable.json") as f: jstr = f.read() headers = {'Content-Type': 'application/json'} res = requests.put(url, jstr, headers=headers, auth=HTTPBasicAuth('admin', 'admin')) print (res.content)
json代码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"
}
]
}
-
硬超时流表下发结果
（4） 编写Python程序，调用OpenDaylight的北向接口获取s1上活动的流表数。
获取流表数代码gettable.py
#!/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)
- 获取流表数结果
- 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。
硬超时流表下发代码overtime2.py
import requests
if name == "main":
url = 'http://127.0.0.1:8080/stats/flowentry/add'
with open("./flowtable.json") as f:
jstr = f.read()
headers = {'Content-Type': 'application/json'}
res = requests.post(url, jstr, headers=headers)
print (res.content)
-
硬超时流表下发结果
（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。
拓扑文件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", "h2")
self.addLink("s1", "h1")
self.addLink("s2", "h3")
self.addLink("s2", "h4")
self.addLink("s2", "s1")
topos = {'mytopo': (lambda: MyTopo())}
（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s.sh
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
- pingall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。
vlan.py
#!/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)
- pingall结果
（三）实验总结
这次实验的难度感觉偏难，而且实验要做的步骤比较多，细节也很多，常常有小错误。尤其是ODL的部分，毕竟是实验四了，好多操作都记不太清了，回去翻了自己的博客也翻了翻大家的博客才找到方法解决，看来还是要多多复习才行。而且在做各个步骤的时候要注意删除之前遗留的东西，该删的删、该关的关，之前的实验老是犯这个错，导致做了好久还是报错。在做实验时遇到的各种各样的报错基本都是使用翻译工具和百度解决的，当然也有一些是在队友们的帮助下完成的。当然还是有一些错误是因为自己没有好好阅读实验指导书或者做试验的时候粗心大意而造成的，因为我是分成几段时间来做试验的，有一次就是建完拓扑忘了开OpenDaylight了，怎么ping都ping不通，所以说做试验时不够认真也是一个需要注意的问题。
