openstack 模块eventlet example code

终于有时间可以仔细研究下openstack依赖的第三方module，主要还是以官方的example入手，熟悉example的思路。

example 01 : 01webcrawler.py

比较简单，使用greenpool和urllib2 直接去抓URL 返回的内容

#! /usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
"""
Eventlet examle coding
1. webcrawler

"""

import eventlet
from eventlet.green import urllib2

urls = [
"https://www.google.com/intl/en_ALL/images/logo.gif",
"http://python.org/images/python-logo.gif",
"http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif",
]

def fetch(url):
print "starting webcrawler",url
body = urllib2.urlopen(url).read()
print "done with", url
return url,body

def main():
greenpool = eventlet.GreenPool(200)
for url,body in greenpool.imap(fetch,urls):
print "got body from ",url,"of length",len(body)

if __name__ == "__main__":
main()

"""
Result:
----------------------------------------------------------------------
starting webcrawler https://www.google.com/intl/en_ALL/images/logo.gif starting webcrawler http://python.org/images/python-logo.gif starting webcrawler http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif done with http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif done with http://python.org/images/python-logo.gif done with https://www.google.com/intl/en_ALL/images/logo.gif got body from  https://www.google.com/intl/en_ALL/images/logo.gif of length 8558
got body from  http://python.org/images/python-logo.gif of length 2549
got body from  http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif of length 1874
"""

example 02 :02wsgiserver.py

实现简单的wsgi server

#! /usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
"""
Eventlet examle coding
2. wsgi servers

"""

import eventlet
from eventlet import wsgi

def hellohandler(env, start_response):
if env['PATH_INFO'] != '/' :
start_response('404 not found',[('Content-Type','test/plain')])
return ['Not Found\r\n']
start_response('200 ok',[('Content-Type','text/plain')])
return ['hello world!\r\n']

def main():
wsgi.server(eventlet.listen(('0.0.0.0',9257)),hellohandler)

if __name__ == '__main__' :
main()

"""
01Testing:
curl http://192.168.32.XX:9257/v1 01Result:
192.168.32.15 - - [06/Feb/2013 10:43:32] "GET /v1 HTTP/1.1" 404 120 0.000624

02Testing:
curl http://192.168.32.XX:9257/ 02Result:
192.168.32.15 - - [06/Feb/2013 10:43:48] "GET / HTTP/1.1" 200 116 0.000514
"""

example 03 :03echoserver.py

实现简单的wsgi server

#! /usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
"""
Eventlet examle coding
2. wsgi servers

"""

import eventlet
from eventlet import wsgi

def hellohandler(env, start_response):
if env['PATH_INFO'] != '/' :
start_response('404 not found',[('Content-Type','test/plain')])
return ['Not Found\r\n']
start_response('200 ok',[('Content-Type','text/plain')])
return ['hello world!\r\n']

def main():
wsgi.server(eventlet.listen(('0.0.0.0',9257)),hellohandler)

if __name__ == '__main__' :
main()

"""
01Testing:
curl http://192.168.32.XX:9257/v1 01Result:
192.168.32.15 - - [06/Feb/2013 10:43:32] "GET /v1 HTTP/1.1" 404 120 0.000624

02Testing:
curl http://192.168.32.XX:9257/ 02Result:
192.168.32.15 - - [06/Feb/2013 10:43:48] "GET / HTTP/1.1" 200 116 0.000514
"""

example 04 : 04socketconnection.py

socket 网络编程的客户端实现

#! /usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
"""
Eventlet examle coding
2. socket connection and greenpile

Note: the pile acts as a collection of return values from the functions
"""

import eventlet
from eventlet.green import socket

def handler(url):
'''
01 create socet
02 get the ip by dns
03 connect
04 socket send
05 return socket recv
'''
sock = socket.socket()
ip = socket.gethostbyname(url)
sock.connect((ip, 80))
print "%s connect" % url
sock.sendall('GET /\r\n\r\n')
return sock.recv(1024)

def main():
'''
01 use greenpile collect the recv from urls
02 handler the socet.sendall and recv
'''
urls = ['www.bing.com', 'www.yandex.ru', 'www.python.org']
pile = eventlet.GreenPile()
for url in urls:
pile.spawn(handler,url)

for url, result in zip(urls, pile):
print "%s : %s" % (url, repr(result)[:50])

if __name__ == '__main__' :
main()

'''
Result:
www.yandex.ru connect
www.python.org connect
www.bing.com connect
www.bing.com : 'HTTP/1.0 400 Bad Request\r\nServer: AkamaiGHost\r
www.yandex.ru : '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Tran
www.python.org : '<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"
'''

example 05 : userChat

051ChatServer.py

#! /usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
"""
Eventlet examle coding
2. socket connection and greenpile

Note: the pile acts as a collection of return values from the functions
"""

import eventlet
from eventlet.green import socket

def handler(url):
'''
01 create socet
02 get the ip by dns
03 connect
04 socket send
05 return socket recv
'''
sock = socket.socket()
ip = socket.gethostbyname(url)
sock.connect((ip, 80))
print "%s connect" % url
sock.sendall('GET /\r\n\r\n')
return sock.recv(1024)

def main():
'''
01 use greenpile collect the recv from urls
02 handler the socet.sendall and recv
'''
urls = ['www.bing.com', 'www.yandex.ru', 'www.python.org']
pile = eventlet.GreenPile()
for url in urls:
pile.spawn(handler,url)

for url, result in zip(urls, pile):
print "%s : %s" % (url, repr(result)[:50])

if __name__ == '__main__' :
main()

'''
Result:
www.yandex.ru connect
www.python.org connect
www.bing.com connect
www.bing.com : 'HTTP/1.0 400 Bad Request\r\nServer: AkamaiGHost\r
www.yandex.ru : '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Tran
www.python.org : '<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"
'''

052ChatClient.py

#! /usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
"""
Eventlet examle coding
2. socket connection and greenpile

Note: the pile acts as a collection of return values from the functions
"""

import eventlet
from eventlet.green import socket

def handler(url):
'''
01 create socet
02 get the ip by dns
03 connect
04 socket send
05 return socket recv
'''
sock = socket.socket()
ip = socket.gethostbyname(url)
sock.connect((ip, 80))
print "%s connect" % url
sock.sendall('GET /\r\n\r\n')
return sock.recv(1024)

def main():
'''
01 use greenpile collect the recv from urls
02 handler the socet.sendall and recv
'''
urls = ['www.bing.com', 'www.yandex.ru', 'www.python.org']
pile = eventlet.GreenPile()
for url in urls:
pile.spawn(handler,url)

for url, result in zip(urls, pile):
print "%s : %s" % (url, repr(result)[:50])

if __name__ == '__main__' :
main()

'''
Result:
www.yandex.ru connect
www.python.org connect
www.bing.com connect
www.bing.com : 'HTTP/1.0 400 Bad Request\r\nServer: AkamaiGHost\r
www.yandex.ru : '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Tran
www.python.org : '<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"
'''

参考信息：

http://eventlet.net/doc/basic_usage.html#greenthread-spawn