RPC(Remote Procedure Call Protocol)是远程调用协议,它通过网络请求服务到远端服务器,服务器根据请求做出响应,将结果返回
它是一种C/S模式,客户端可以调用远程服务器上的参数(类似URL)并返回结果
利用rpc可以实现系统的分布式架构,可以将功能分解到多台服务器上进行实现,同时也将也可以将负载打散,分布到不同服务器上,整合计算资源
在openstack中就大量使用了rpc
rpc多使用http传输请求,格式有xml,json等,这里是xml
模块:
注:xmlrpclib模块在python3中重命名为xmlrpc.client
xmlrpc并不是很安全,但在2.7.9 https url中默认加入了证书,主机名验证
定义:
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class xmlrpclib.ServerProxy(uri[, transport[, encoding[, verbose[, allow_none[, use_datetime[, context]]]]]]) |
1.uri,即服务端的url地址
2.transport 传输实例,可选,https urls/http
3.encoding
4.verbose 是debug模式
5.allow_none 是否请求空 ,若为True,那么常量none将被翻译成xml,默认如果是none则抛出异常 TypeError
6.use_datetime 可以使用date/time values记录调用时间datetime.datetime,默认是false
ServerProxy对象提供一些默认的方法:
1.ServerProxy.system.listMethods() 返回远端服务器方法列表
2.ServerProxy.system.methodSignature(name) 方法签名,是一个数组类型
3.ServerProxy.system.methodHelp(name) 方法帮助信息
例如一个简单的示例:
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import xmlrpclib from SimpleXMLRPCServer import SimpleXMLRPCServer def get_power(n,m): return n * * m server = SimpleXMLRPCServer(( "0.0.0.0" , 8081 )) print "start service get power on 0.0.0.0 8081..." server.register_function(get_power, "get_power" ) server.serve_forever() |
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import xmlrpclib server_power = xmlrpclib.ServerProxy( "http://192.168.137.9:8081/" ) print "3**2 = %d" % (server_power.get_power( 3 , 2 )) print "2**5 = %d" % (server_power.get_power( 2 , 5 )) |
结果:
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# python xml_server.py start service get power on 0.0 . 0.0 8081. .. 192.168 . 137.9 - - [ 22 / May / 2017 10 : 37 : 47 ] "POST / HTTP/1.1" 200 - 192.168 . 137.9 - - [ 22 / May / 2017 10 : 37 : 47 ] "POST / HTTP/1.1" 200 - |
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# python xml_client.py 3 * * 2 = 9 2 * * 5 = 32 |
xmlrpclib提供的一些方法:
class xmlrpclib.DateTime 时间对象
例如:
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import datetime from SimpleXMLRPCServer import SimpleXMLRPCServer import xmlrpclib def today(): today = datetime.datetime.today() return xmlrpclib.DateTime(today) server = SimpleXMLRPCServer(( "0.0.0.0" , 8081 )) print "start service on 0.0.0.0 8081..." server.register_function(today, "today" ) server.serve_forever() |
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import xmlrpclib import datetime s = xmlrpclib.ServerProxy( "http://192.168.137.9:8081/" ) today = s.today() converted = datetime.datetime.strptime(today.value, "%Y%m%dT%H:%M:%S" ) print "Today: %s" % converted.strftime( "%d.%m.%Y, %H:%M" ) |
结果:
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# python rpc_time.py start service on 0.0 . 0.0 8081. .. 192.168 . 137.9 - - [ 22 / May / 2017 10 : 43 : 19 ] "POST / HTTP/1.1" 200 - |
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# python rpc_time_client.py Today: 22.05 . 2017 , 10 : 43 |
2.class xmlrpclib.Binary 二进制对象
3.class xmlrpclib.Fault fault对象
如:
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import xmlrpclib s = xmlrpclib.ServerProxy( "http://192.168.137.9:8081/" ) try : s.add( 2 , 5 ) except xmlrpclib.Fault as err: print "A fault occurred" print "Fault code: %d" % err.faultCode print "Fault string: %s" % err.faultString |
class xmlrpclib.MultiCall(server) 提供多个调用,复合调用:
例如:
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from SimpleXMLRPCServer import SimpleXMLRPCServer def add(x,y): return x + y def subtract(x, y): return x - y def multiply(x, y): return x * y def divide(x, y): return x / y def get_power(n,m): return n * * m server = SimpleXMLRPCServer(( "0.0.0.0" , 8081 )) print "start service on 0.0.0.0 8081..." server.register_multicall_functions() server.register_function(add, 'add' ) server.register_function(subtract, 'subtract' ) server.register_function(multiply, 'multiply' ) server.register_function(divide, 'divide' ) server.register_function(get_power, 'get_power' ) server.serve_forever() |
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import xmlrpclib s = xmlrpclib.ServerProxy( "http://192.168.137.9:8081/" ) multicall = xmlrpclib.MultiCall(s) multicall.add( 7 , 3 ) multicall.subtract( 7 , 3 ) multicall.multiply( 7 , 3 ) multicall.divide( 7 , 3 ) multicall.get_power( 7 , 3 ) result = multicall() print "7+3=%d, 7-3=%d, 7*3=%d, 7/3=%d 7**3=%d" % tuple (result) |
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# python mul_xmlserver.py start service on 0.0 . 0.0 8081. .. 192.168 . 137.9 - - [ 22 / May / 2017 10 : 51 : 59 ] "POST / HTTP/1.1" 200 - |
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# python mul_xmlclient.py 7 + 3 = 10 , 7 - 3 = 4 , 7 * 3 = 21 , 7 / 3 = 2 7 * * 3 = 343 |
另外xmlrpc还提供有比较快捷的函数:
1.xmlrpclib.boolean(value) 将任意的python值转换成xmlrpc的布尔类型True/False
2.xmlrpclib.dumps(params[, methodname[, methodresponse[, encoding[, allow_none]]]])
params请求转换为xml
3.xmlrpclib.loads(data[, use_datetime])
将一个xml-rpc的请求转换成python对象
例如:
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from xmlrpclib import ServerProxy, Error server = ServerProxy( "http://betty.userland.com" ) print server try : print server.examples.getStateName( 41 ) except Error as err: print "ERROR" , err |
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import xmlrpclib, httplib class ProxiedTransport(xmlrpclib.Transport): def set_proxy( self , s): self .s = s def make_connection( self , host): self .realhost = host h = httplib.HTTPConnection( self .s) return h def send_request( self , connection, handler, request_body): connection.putrequest( "POST" , ' http://%s%s ' % ( self .realhost, handler)) def send_host( self , connection, host): connection.putheader( 'Host' , self .realhost) p = ProxiedTransport() p.set_proxy( 'proxy-server:8080' ) server = xmlrpclib.ServerProxy( ' http://time.xmlrpc.com/RPC2 ' , transport = p) print server.currentTime.getCurrentTime() |
以上这篇python远程调用rpc模块xmlrpclib的方法就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/comprel/article/details/72633406