Usage: rails server [mongrel, thin, etc] [options]
-p, --port=port Runs Rails on the specified port.
Default: 3000
-b, --binding=ip Binds Rails to the specified ip.
Default: 0.0.0.0
-c, --config=fileUse custom rackup configuration file
-d, --daemon Make server run as a Daemon.
-u, --debugger Enable ruby-debugging for the server.
-e, --environment=name Specifies the environment to run this server under (test/development/production).
Default: development
-P, --pid=pidSpecifies the PID file.
Default: tmp/pids/server.pid
-h, --help Show this help message.
在以前,你选择Pythonweb架构会受制于可用的web服务器,反之亦然。如果架构和服务器可以协同工作,那你就走运了:但你有可能面对(或者曾有过)下面的问题,当要把一个服务器和一个架构结合起来是发现他们不是被设计成协同工作的:
基本上你只能用可以一起运行的而非你想要使用的。
那么,你怎么可以不修改服务器和架构代码而确保可以在多个架构下运行web服务器呢?答案就是PythonWebServerGatewayInterface(或简称WSGI,读作“wizgy”)。
WSGI允许开发者将选择web框架和web服务器分开。现在你可以混合匹配web服务器和web框架,选择一个适合你需要的配对。比如,你可以在Gunicorn或者Nginx/uWSGI或者Waitress上运行Django,Flask,或Pyramid。真正的混合匹配,得益于WSGI同时支持服务器和架构:
WSGI是第一篇和这篇开头又重复问道问题的答案。你的web服务器必须具备WSGI接口,所有的现代PythonWeb框架都已具备WSGI接口,它让你不对代码作修改就能使服务器和特点的web框架协同工作。
现在你知道WSGI由web服务器支持,而web框架允许你选择适合自己的配对,但它同样对于服务器和框架开发者提供便利使他们可以专注于自己偏爱的领域和专长而不至于相互牵制。其他语言也有类似接口:java有ServletAPI,Ruby有Rack。
说这么多了,你肯定在喊,给我看代码!好吧,看看这个极简的WSGI服务器实现:
#TestedwithPython2.7.9,Linux&MacOSX
importsocket
importStringIO
importsys
classWSGIServer(object):
address_family=socket.AF_INET
socket_type=socket.SOCK_STREAM
request_queue_size=1
def__init__(self,server_address):
#Createalisteningsocket
self.listen_socket=listen_socket=socket.socket(
self.address_family,
self.socket_type
)
#Allowtoreusethesameaddress
listen_socket.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
#Bind
listen_socket.bind(server_address)
#Activate
listen_socket.listen(self.request_queue_size)
#Getserverhostnameandport
host,port=self.listen_socket.getsockname()[:2]
self.server_name=socket.getfqdn(host)
self.server_port=port
#ReturnheaderssetbyWebframework/Webapplication
self.headers_set=[]
defset_app(self,application):
self.application=application
defserve_forever(self):
listen_socket=self.listen_socket
whileTrue:
#Newclientconnection
self.client_connection,client_address=listen_socket.accept()
#Handleonerequestandclosetheclientconnection.Then
#loopovertowaitforanotherclientconnection
self.handle_one_request()
defhandle_one_request(self):
self.request_data=request_data=self.client_connection.recv(1024)
#Printformattedrequestdataala'curl-v'
print(''.join(
'<{line}\n'.format(line=line)
forlineinrequest_data.splitlines()
))
self.parse_request(request_data)
#Constructenvironmentdictionaryusingrequestdata
env=self.get_environ()
#It'stimetocallourapplicationcallableandget
#backaresultthatwillbecomeHTTPresponsebody
result=self.application(env,self.start_response)
#Constructaresponseandsenditbacktotheclient
self.finish_response(result)
defparse_request(self,text):
request_line=text.splitlines()[0]
request_line=request_line.rstrip('\r\n')
#Breakdowntherequestlineintocomponents
(self.request_method,#GET
self.path,#/hello
self.request_version#HTTP/1.1
)=request_line.split()
defget_environ(self):
env={}
#ThefollowingcodesnippetdoesnotfollowPEP8conventions
#butit'sformattedthewayitisfordemonstrationpurposes
#toemphasizetherequiredvariablesandtheirvalues
#
#RequiredWSGIvariables
env['wsgi.version']=(1,0)
env['wsgi.url_scheme']='http'
env['wsgi.input']=StringIO.StringIO(self.request_data)
env['wsgi.errors']=sys.stderr
env['wsgi.multithread']=False
env['wsgi.multiprocess']=False
env['wsgi.run_once']=False
#RequiredCGIvariables
env['REQUEST_METHOD']=self.request_method#GET
env['PATH_INFO']=self.path#/hello
env['SERVER_NAME']=self.server_name#localhost
env['SERVER_PORT']=str(self.server_port)#8888
returnenv
defstart_response(self,status,response_headers,exc_info=None):
#Addnecessaryserverheaders
server_headers=[
('Date','Tue,31Mar201512:54:48GMT'),
('Server','WSGIServer0.2'),
]
self.headers_set=[status,response_headers+server_headers]
#ToadheretoWSGIspecificationthestart_responsemustreturn
#a'write'callable.Wesimplicity'ssakewe'llignorethatdetail
#fornow.
#returnself.finish_response
deffinish_response(self,result):
try:
status,response_headers=self.headers_set
response='HTTP/1.1{status}\r\n'.format(status=status)
forheaderinresponse_headers:
response+='{0}:{1}\r\n'.format(*header)
response+='\r\n'
fordatainresult:
response+=data
#Printformattedresponsedataala'curl-v'
print(''.join(
'>{line}\n'.format(line=line)
forlineinresponse.splitlines()
))
self.client_connection.sendall(response)
finally:
self.client_connection.close()
SERVER_ADDRESS=(HOST,PORT)='',8888
defmake_server(server_address,application):
server=WSGIServer(server_address)
server.set_app(application)
returnserver
if__name__=='__main__':
iflen(sys.argv)<2:
sys.exit('ProvideaWSGIapplicationobjectasmodule:callable')
app_path=sys.argv[1]
module,application=app_path.split(':')
module=__import__(module)
application=getattr(module,application)
httpd=make_server(SERVER_ADDRESS,application)
print('WSGIServer:ServingHTTPonport{port}...\n'.format(port=PORT))
httpd.serve_forever()
这比第一篇的代码长的多,但也足够短(只有150行)来让你理解而避免在细节里越陷越深。上面的服务器可以做更多——可以运行你钟爱web框架所写基本的web应用,Pyramid,Flask,Django,或其他PythonWSGI框架.
不相信我?你自己试试看。保存上面的代码为webserver2.py或者直接在Github下载。如果你不传入任何参数它会提醒然后推出。
$pythonwebserver2.py
ProvideaWSGIapplicationobjectasmodule:callable
请确保当你安装和使用vmc时候使用带Ruby功能的命令提示符窗口,从Windows的“开始”菜单中的“所有程序”→“Ruby<VERSION>→启动命令提示符使用Ruby"。最后,从Ruby命令提示符更新RubyGems
prompt>gem update --system
Windows Gemfiles支持
一旦你安装了Ruby,你可以按照说明来部署app和使用Gemfile,部署Ruby应用到Cloud Foundry
Windows用户要注意以下几点:
当Windows机器上生成Gemfile.lock文件,它往往包含与Windows匹配特定版本的gems,例如mysql2,thin,PG含有“-X86-mingw32的”的后缀。
例如,在Windows机器上运行包安装用的Gemfile,看起来像这样:
gem 'sinatra'
gem 'mysql2'
gem 'json'
结果是Gemfile.lock看起来如下:
GEMremote: http://rubygems.org/specs: json (1.7.3) mysql2 (0.3.11-x86-mingw32) rack (1.4.1) rack-protection (1.2.0)rack sinatra (1.3.2)rack (~>1.3, >= 1.3.6)rack-protection (~>1.2)tilt (~>1.3, >= 1.3.3) tilt (1.3.3)PLATFORMSx86-mingw32DEPENDENCIESjsonmysql2sinatra
Cloud Foundry能够正确地安装这些gems,而不需要修改你的Gemfile.lock