（一）基本要求
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编写Python程序，调用OpenDaylight的北向接口实现以下功能
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利用Mininet平台搭建下图所示网络拓扑，并连接OpenDaylight；
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下发指令删除s1上的流表数据。
delete.py代码
#!/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)
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下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。
timeout.py代码
#!/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)
timeout.json代码{ "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" } ] }
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获取s1上活动的流表数。
getflow.py代码
#!/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)
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编写Python程序，调用Ryu的北向接口实现以下功能
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实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。
timout_ryu.py代码
#!/usr/bin/python import requests from requests.auth import HTTPBasicAuth def http_post(url,jstr): url = url headers = {'Content-Type':'application/json'} resp = requests.post(url,jstr,headers=headers) return resp if __name__ == "__main__": url = 'http://127.0.0.1:8080/stats/flowentry/add' with open("./timeout_ryu.json") as f: jstr = f.read() resp = http_post(url,jstr) print (resp.content)timeout_ryu.json代码
{ "dpid": 1, "cookie": 1, "cookie_mask": 1, "table_id": 0, "hard_timeout": 20, "priority": 65535, "flags": 1, "match":{ "in_port":1 }, "actions":[ ] }
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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。
topo.py代码
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())}vlan.py代码
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)
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（二）进阶要求
Ryu，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。
getall.py代码
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()
个人总结
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python xx.py时报错
解决方法：代码改为
python3 xx.py -
生成拓扑并连接控制器，若连接的是Ryu，需要同时开启REST API和运行一个支持OpenFlow 1.3的交换机。
ryu-manager ryu.app.simple_switch_13 ryu.app.ofctl_rest -
删除流表时发现未安装curl
解决方法：
sudo apt install curl -
本次实验难度较大，需要将前几次实验特别是OpenDaylight和Ryu部分理解清楚并掌握好。Python能力差，编写代码花费很长时间。 通过本次实验，我进一步熟悉了OpenDaylight和Ryu的使用，并了解了相关API的使用，同时也锻炼了信息检索和阅读文档的能力。