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
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 --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。
- del.py 代码
import requests
from requests.auth import HTTPBasicAuth
def del_table(url):
headers = {'Content-Type' : 'application/json'}
return requests.delete(url, headers = headers, auth=HTTPBasicAuth('admin', 'admin'))
if __name__ == "__main__":
url= 'http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/'
res = del_table(url)
print (res.content)
- 执行结果:
(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
- delay_table.py
import requests
from requests.auth import HTTPBasicAuth
def delay_flowtable(url, jstr):
headers = {'Content-Type':'application/json'}
return requests.put(url, jstr, headers=headers, auth=HTTPBasicAuth('admin', 'admin'))
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('./flowtable1.json') as f:
jstr = f.read()
resp = delay_flowtable(url,jstr)
print (resp.content)
- tableflow1.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"
}
]
}
- 执行结果
(4)编写Python程序,调用OpenDaylight的北向接口获取s1上活动的流表数
- 代码
import requests
from requests.auth import HTTPBasicAuth
def get_table(url):
headers = {'Content-Type':'application/json'}
return requests.get(url,headers=headers,auth=HTTPBasicAuth('admin','admin'))
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 = get_table(url)
print(resp.content)
- 运行结果
(二) 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
- 代码
#!/usr/bin/python
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)
- flowtable2.json
{
"dpid": 1,
"cookie": 1,
"cookie_mask": 1,
"table_id": 0,
"hard_timeout": 20,
"priority": 65535,
"flags": 1,
"match":{
"in_port":1
},
"actions":[
]
}
- 运行结果
(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
- 生成的topo.py代码
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())}
- 连接ryu控制器
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest
-
命令行输入以下命令创建拓扑:
sudo sudo mn --custom topo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13 -
创建结果
(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
# 将主机1,2发送来的包打上vlan标记</font>
curl -X POST -d '{
"dpid": 1,
"priority": 1,
"match":{
"in_port": 1
},
"actions":[
{
"type": "PUSH_VLAN", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"type": "SET_FIELD",
"field": "vlan_vid", # Set VLAN ID
"value": 4096 # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=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", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"type": "SET_FIELD",
"field": "vlan_vid", # Set VLAN ID
"value": 4097 # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=4096)
},
{
"type": "OUTPUT",
"port": 3
}
]
}' http://localhost:8080/stats/flowentry/add
<font size=4>
# 将主机3,4发送来的包取出vlan标记</font>
curl -X POST -d '{
"dpid": 1,
"priority": 1,
"match":{
"vlan_vid": 0
},
"actions":[
{
"type": "POP_VLAN", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"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", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"type": "OUTPUT",
"port": 2
}
]
}' http://localhost:8080/stats/flowentry/add
</br>
# 将主机3,4发送来的包打上vlan标记
curl -X POST -d '{
"dpid": 2,
"priority": 1,
"match":{
"in_port": 1
},
"actions":[
{
"type": "PUSH_VLAN", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"type": "SET_FIELD",
"field": "vlan_vid", # Set VLAN ID
"value": 4096 # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=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", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"type": "SET_FIELD",
"field": "vlan_vid", # Set VLAN ID
"value": 4097 # Describe sum of vlan_id(e.g. 6) | OFPVID_PRESENT(0x1000=4096)
},
{
"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", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"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", # Push a new VLAN tag if a input frame is non-VLAN-tagged
"ethertype": 33024 # Ethertype 0x8100(=33024): IEEE 802.1Q VLAN-tagged frame
},
{
"type": "OUTPUT",
"port": 2
}
]
}' http://localhost:8080/stats/flowentry/add
- 执行结果
四 进阶要求
编程实现基本要求第2部分Ryu(3)中的VLAN划分
- 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": 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)
- 运行结果
五、个人总结
- 难度评价
本次作业实验我感觉内容有点多,存在一定的难度,主要在阅读代码和文档上面。参考了同学优秀的博客,受到很多启发,同时也感觉到自己还是太菜了,特此感谢同学的帮助。
- 实验过程遇到的困难及解决办法:
1.连接拓扑后,一直无法ping通,导致作业卡顿了很久,同学的一句话点醒了我,原来是没有控制器,也就是ryu控制器没有连接。把ryu控制连接后,顺利ping通。(太低级了错误属实丢人)
2.在进行ryu的第三个步骤实验时候,应该先把原流表删除,在用运行shell程序。
3.openflow版本,习惯性的写上1.0版本。导致无法ping通现象,问了同学,改成openflow1.3,顺利解决
- 个人感想
做完作业,自信心有点受崩,可能这段时期状态也不是很好,一直在一些小细节上出问题,导致实验停滞,完成时间不断后拖。同学懂得很多也很优秀,希望自己慢慢能努力能向他们看齐。本次实验加深了自己对sdn三层体系架构的理解。通过调用北向接口的api,使得我在控制器管理,编程控制有了新的掌握。