实验7：基于REST API的SDN北向应用实践
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。
实验要求
基本要求
- 编写Python程序，调用OpenDaylight的北向接口实现以下功能
（1） 利用Mininet平台搭建下图所示网络拓扑，并连接；
-
搭建拓扑
sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13
-
Carbon版本连接OpenDaylight:
./distribution-karaf-0.6.4-Carbon/bin/karaf
（2） 下发指令删除s1上的流表数据。
-
创建并编写delete.py文件
touch delete.py# delete.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/' headers = {'Content-Type': 'application/json'} res = requests.delete(url, headers=headers, auth=HTTPBasicAuth('admin', 'admin')) print (res.content) -
lab7终端输入
python3 delete.py
（3) 下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。
-
创建并编写
hardtimeout.py文件# timeout.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("./timeout.json") as file: str = file.read() headers = {'Content-Type': 'application/json'} res = requests.put(url, str, headers=headers, auth=HTTPBasicAuth('admin', 'admin')) print (res.content) -
创建并编写
hardtimeout.json文件# 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": "flow", "priority": "65535", "hard-timeout": "20", "cookie": "2", "table_id": "0" } ] } -
命令输入
h1 ping h3并在另一窗口输入python hardtimeout.py
(4) 获取s1上活动的流表数。
-
创建并编写
getflow.py文件# getflow.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) -
命令行输入
python getflow.py
- 编写Python程序，调用Ryu的北向接口实现以下功能
（1） 实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。
-
创建并编写
ryu_timeout.py文件# ryu_timeout.py import requests if __name__ == "__main__": url = 'http://127.0.0.1:8080/stats/flowentry/add' with open("./ryu_timeout.json") as file: str = file.read() headers = {'Content-Type': 'application/json'} res = requests.post(url, str, headers=headers) print (res.content) -
创建并编写
ryu_timeout.json文件# ryu_timeout.json { "dpid": 1, "cookie": 1, "cookie_mask": 1, "table_id": 0, "hard_timeout": 20, "priority": 65535, "flags": 1, "match":{ "in_port":1 }, "actions":[ ] } -
关闭ODL控制器，关闭上次的拓扑并清除拓扑
sudo mn -c -
启动ryu控制器
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest -
创建拓扑
sudo mn --topo=single,3 --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13 -
h1 ping h3, 运行python ryu_timeout.py（2） 参考Ryu REST API的文档，基于VLAN实验的网络拓扑，编程实现相同的VLAN配置。
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创建并编写
ryu_topo.py文件# ryu_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())} -
创建并编写
ryu_vlan.py文件# ryu_vlan.py 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) -
关闭控制器，关闭上一次实验的拓扑并清除
sudo mn -c -
启动Ryu控制器
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest -
创建拓扑
sudo sudo mn --custom ryu_topo.py --topo mytopo --mac --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13 -
删除流表
curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/1
curl -X DELETE http://127.0.0.1:8080/stats/flowentry/clear/2 -
运行
python ryu_vlan.py并pingall
进阶要求
OpenDaylight或Ryu任选其一，编程实现查看前序VLAN实验拓扑中所有节点（含交换机、主机）的名称，以及显示每台交换机的所有流表项。
- 创建并编写
getall.py文件
# getall.py
import requests
import time
import re
class GetNodes:
def __init__(self, ip):
self.ip = ip
def get_switch_id(self):
url = 'http://' + self.ip + '/stats/switches'
re_switch_id = requests.get(url=url).json()
switch_id_hex = []
for i in re_switch_id:
switch_id_hex.append(hex(i))
return switch_id_hex
def getflow(self):
url = 'http://' + self.ip + '/stats/flow/%d'
switch_list = self.get_switch_id()
ret_flow = []
for switch in switch_list:
new_url = format(url % int(switch, 16))
re_switch_flow = requests.get(url=new_url).json()
ret_flow.append(re_switch_flow)
return ret_flow
def show(self):
flow_list = self.getflow()
for flow in flow_list:
for dpid in flow.keys():
dp_id = dpid
switchnum= '{1}'.format(hex(int(dp_id)), int(dp_id))
print('s'+switchnum,end = " ")
switchnum = int(switchnum)
for list_table in flow.values():
for table in list_table:
string1 = str(table)
if re.search("'dl_vlan': '(.*?)'", string1) is not None:
num = re.search("'dl_vlan': '(.*?)'", string1).group(1);
if num == '0' and switchnum == 1:
print('h1',end = " ")
if num == '1' and switchnum == 1:
print('h2',end = " ")
if num == '0' and switchnum == 2:
print('h3',end = " ")
if num == '1' and switchnum == 2:
print('h4',end = " ")
print("")
flow_list = self.getflow()
for flow in flow_list:
for dpid in flow.keys():
dp_id = dpid
print('switch_name:s{1}'.format(hex(int(dp_id)), int(dp_id)))
for list_table in flow.values():
for table in list_table:
print(table)
s1 = GetNodes("127.0.0.1:8080")
s1.show()
-
运行
python getall.py -
dpctl dump-flows -O OpenFlow13 s1 -
dpctl dump-flows -O OpenFlow13 s2 -
dpctl dump-flows
个人感想
这次试验难度较大，用上了前几次实验的知识经验，并且对API的查看要求很高，要学会查看文档，从一堆英文里面找到自己需要的接口、代码。这一次实验里编写代码十分困难且耗时间，需要一点一点去琢磨怎么写代码，不过还好有同学的可以参照、对比，这样按部就班来写好代码后也会有点成就感。不过还是会遇到很多莫名其妙的问题，所以到头来还是要学会用搜索引擎，我觉得这是学习中最重要的事情之一了。
标签：__,url,self,flow,REST,headers,API,SDN,requests From： https://www.cnblogs.com/wojiuyishui/p/16827982.html