实验7：基于REST API的SDN北向应用实践

基本实验

实验步骤1

利用Mininet平台搭建下图所示网络拓扑，并连接OpenDaylight；
首先运行ODL
在终端输入sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
在浏览器中访问http://127.0.0.1:8181/index.html查看拓扑

实验步骤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。
编写代码并命名为delete.py
在终端执行该代码删除流表数据
`#delete.py
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)`

执行结果

实验步骤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。
编写代码并命名为puts.py以及ODL_flowtable.json文件
mininet命令行内输入h1 ping h3 ，终端输入python3 puts.py执行该程序
`#puts.py
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("./ODL_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) `

ODL_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" } ] }

执行结果

实验步骤4

编写Python程序，调用OpenDaylight的北向接口获取s1上活动的流表数。
编写代码并命名为get.py
在终端执行该代码获取流表数
`#get.py
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)`

执行结果

实验步骤5

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。
编写代码并命名为ryu_put.py以及flowtable.json
首先终端输入命令：ryu-manager ryu/ryu/app/gui_topology/gui_topology.py --observe-links 连接ryu控制器
在ryu/ryu/app/文件夹内运行终端输入命令：ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest 运行ryu
终端输入curl -X GET http://localhost:8080/stats/flow/1查看流表
终端输入命令：sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13建立拓扑
mininet命令行下输入h1 ping h3
终端执行程序，产生中断
`#ryu_put.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)
flowtable.json
{
"dpid": 1,
"cookie": 1,
"cookie_mask": 1,
"table_id": 0,
"hard_timeout": 20,
"priority": 65535,
"flags": 1,
"match":{
"in_port":1
},
"actions":[

执行结果

实验步骤6

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。
编写以下代码，命名为topo.py
`#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())}`

首先终端输入命令：ryu-manager ryu/ryu/app/gui_topology/gui_topology.py --observe-links 连接ryu控制器
在ryu/ryu/app/文件夹内运行终端输入命令：ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest 运行ryu
终端输入curl -X GET http://localhost:8080/stats/flow/1查看流表
终端输入命令：sudo sudo mn --custom topo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13建立拓扑
执行结果

实验步骤7

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。
终端输入命令：curl -X DELETE http://localhost:8080/stats/flowentry/clear/1和curl -X DELETE http://localhost:8080/stats/flowentry/clear/2删除流表
编写shell脚本，并命名为VLAN.py
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

运行脚本程序，可在mininet中通过pingall检验VLAN划分结果
执行结果

个人总结

实验难度:

较难

实验过程遇到的困难及解决办法
是运行了ryu，但是ping测试却显示各主机均不连通，上网查不到答案，之后看了同学的博客，发现了一样的问题，于是试着做了一遍发现成功了，命令行需要运行curl -X GET http://localhost:8080/stats/flow/1 查看流表，在利用自己代码建立拓扑时候，终端输入时候没有加上custom参数，导致连接出错一直存在。最后一个实验步骤无法得到正确的VLAN划分结果，在网络上找不到答案，于是我就参考了同学的博客园，查看同学的个人总结，发现是由于没有删除之前遗留的流表所致。
个人感想
经过本次实验，学习了编写程序调用OpenDaylight的北向接口实现部分功能，使我对基于REST API的SDN北向应用有了深刻的认识，也对流表遗留的危害有了深刻印象，下发硬超时流表和获取s1上活动的流表数；并调用Ryu REST API实现下发硬超时流表、实现和实验2相同的VLAN，学习了shell脚本的相关命令的使用，对了curl命令部分运用也有了初步学习，对于虚拟网的实现有了更深层次的理解和掌握了。

posted @ 2021-10-26 18:37 巴鲁ac 阅读(62) 评论(0) 编辑收藏举报

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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

基本实验

实验步骤1

实验步骤2

实验步骤3

实验步骤4

实验步骤5

实验步骤6

实验步骤7

个人总结

实验难度:

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