Mailman 3 March 2007 - Twisted

[Twisted-Python] Twisted Python 0.7.0 Prerelease Testing
by Glyph Lefkowitz 05 Aug '21

05 Aug '21

hi there, folks: I'd really like to release 0.7.0 but I would like it to be at least a little bit tested before I do so. Could those of you with CVS trees check everything out and see if it performs as advertised? Deeper bugs than that will have to wait for the next release, but I'd at least like to know if it works for someone other than me. Thanks. ______ __ __ _____ _ _ | ____ | \_/ |_____] |_____| |_____| |_____ | | | | @ t w i s t e d m a t r i x . c o m http://www.twistedmatrix.com/~glyph/

4 5

[Twisted-Python] Get IP of connecting client in XMLRPC server
by Remy C. Cool 28 Apr '13

28 Apr '13

Hello, On 18 May 2004, the following message was posted to this mailinglist: Jp Calderone exarkun at divmod.com wrote: >Daniel Newton wrote: > > I have a simple XML-PRC server similar to the example below: > > from twisted.web import xmlrpc, server > > class Example(xmlrpc.XMLRPC): > """An example object to be published.""" > > def xmlrpc_add(self, a, b): > """Return sum of arguments.""" > return a + b def xmlrpc_whatIsMyAddress(self): return self.transport.getPeer().host > > if __name__ == '__main__': > from twisted.internet import reactor > r = Example() > reactor.listenTCP(7080, server.Site(r)) > reactor.run() > > I want to be able to get the address of the client that calls the xmlrpc > method can anyone help me with this? This solution didn't work because 'transport' isn't a property of the Example class. I'm currently in the process of changing from a customized SimpleXMLRPCServer to a twisted XMLRPC server solution and I need to insert the client IP into the attributes passed to the called xmlrpc method. Anyone who knows the answer and is willing to share the info? Regards, Remy

3 3

[Twisted-Python] Reconnecting PB Client
by Don Smith 12 Sep '07

12 Sep '07

Does anyone have some example code for building a reconnecting PB client? This is what I have now: from twisted.spread import pb from twisted.internet import reactor from twisted.python import util events = pb.PBClientFactory() reactor.connectTCP("localhost", 8789, events) queue = events.getRootObject()

3 2

[Twisted-Python] twisted pysnmp status
by Brendan Simon 18 Apr '07

18 Apr '07

Hi, I just wanted to know what the latest status is with twisted and pysnmp. Is pysnmp 4.x supported? Is full SNMPv3 supported? What is the roadmap and/or plans for twisted and pysnmp ??? I want to write and SNMPv3 GUI manager in python :) I'm not sure if the complexity and dependency of twisted is worth the effort? Then again on the other hand it may provide lots of things I would probably need to write anyway ? Given I would also like SSH and maybe even WBEM and/or WS-Management protocols too, then maybe twisted provides a better framework ??? Cheers, Brendan.

4 7

[Twisted-Python] exceptions.TypeError: ('Could not adapt', <twisted.spread.pb._PortalAuthChallenger instance at 0x013E3760>, <InterfaceClass twisted.cred.credentials.IUsernamePassword>)
by Justin Johnson 30 Mar '07

30 Mar '07

Hi, I'm running Python 2.5 and Twisted 2.5.0 on Windows 2003 Server. I have a web site (Twisted/Nevow) where users login with a username and password. I save the username and password once they login because the same username and password are used to connect to various Perspective Broker servers, and I don't want to make users reauthenticate for every server that is connected to behind the scenes. Since the password cannot be hashed when passed to PB I store it in plaintext. Up to this point I have been using a realm and file password db as listed at the end of this email. When I recently upgraded from Twisted 2.4.0 to 2.5.0 and from Python 2.4 to 2.5 I get the following error. 2007/03/28 10:23 -0500 [Broker,0,IP_ADDRESS] Peer will receive following PB traceback: 2007/03/28 10:23 -0500 [Broker,0,IP_ADDRESS] Unhandled Error Traceback (most recent call last): File "D:\Python25\lib\site-packages\twisted\spread\pb.py", line 847, in _recvMessage netResult = object.remoteMessageReceived(self, message, netArgs, netKw) File "D:\Python25\lib\site-packages\twisted\spread\flavors.py", line 119, in remoteMessageReceived state = method(*args, **kw) File "D:\Python25\lib\site-packages\twisted\spread\pb.py", line 1217, in remote_respond d = self.portalWrapper.portal.login(self, mind, IPerspective) File "D:\Python25\lib\site-packages\twisted\cred\portal.py", line 109, in login return maybeDeferred(c.requestAvatarId, credentials --- <exception caught here> --- File "D:\Python25\lib\site-packages\twisted\internet\defer.py", line 107, in maybeDeferred result = f(*args, **kw) File "d:\python25\lib\site-packages\ratcontrol\login.py", line 195, in requestAvatarId up = credentials.IUsernamePassword(c) exceptions.TypeError: ('Could not adapt', <twisted.spread.pb._PortalAuthChallenger instance at 0x013E3760>, <InterfaceClass twisted.cred.credentials.IUsernamePassword>) 2007/03/28 10:23 -0500 [Broker,client] Unhandled error in Deferred: 2007/03/28 10:23 -0500 [Broker,client] Unhandled Error Traceback from remote host -- Traceback unavailable I looked at the Subversion log for twisted.spread.pb.py and am not sure what change is causing this failure. The contents of ratcontrol\login.py are below. Does anyone have any pointers on what I should be looking for here? Is there any way I can accomplish my goal in a more maintainable way? Thanks, Justin ---------------- from twisted.cred import portal, checkers, credentials, error from twisted.web import resource from twisted.spread import pb from twisted.python import log, components from twisted.internet.defer import maybeDeferred from twisted.internet import defer from twisted.python import failure, reflect, components from zope.interface import implements from nevow import inevow from ratcontrol.web import pages from ratcontrol import perspectives from ratcontrol import services def noLogout(): return None class RatControlRealm: """A simple implementor of cred's IRealm. For web, this gives us the LoggedIn page. For PB, this gives us a reference to the perspective. """ implements(portal.IRealm) def __init__(self): self.clients = [] self.serviceTypes = [] def addServiceType(self, serviceType): self.serviceTypes.append(serviceType) def requestAvatar(self, avatarIdAndPassword, mind, *interfaces): ## If the login is anonymous, only one item will be passed. ## If it is an authorized login, both the id and password ## will be passed. if len(avatarIdAndPassword) == 2: avatarId, avatarPassword = avatarIdAndPassword else: avatarId = avatarIdAndPassword for iface in interfaces: if iface is inevow.IResource: if avatarId is checkers.ANONYMOUS: resc = pages.NotLoggedIn() return (resource.IResource, resc, noLogout) else: resc = pages.LoggedIn(avatarId, avatarPassword, self) return resource.IResource, resc, noLogout elif iface is pb.IPerspective: if avatarId is checkers.ANONYMOUS: return (pb.IPerspective, None, None) else: log.msg("User %s logged in" % avatarId) #s = services.RatControlService() s = services.getServiceForTypes(self.serviceTypes) self.p = perspectives.IPerspectiveRatControl(s) self.p.loggedIn = 1 return (pb.IPerspective, self.p, self.p.logout) raise NotImplementedError("Can't support that interface.") class FilePasswordDB: """A file-based, text-based username/password database. Records in the datafile for this class are delimited by a particular string. The username appears in a fixed field of the columns delimited by this string, as does the password. Both fields are specifiable. If the passwords are not stored plaintext, a hash function must be supplied to convert plaintext passwords to the form stored on disk and this CredentialsChecker will only be able to check IUsernamePassword credentials. If the passwords are stored plaintext, IUsernameHashedPassword credentials will be checkable as well. """ implements(checkers.ICredentialsChecker) def __init__(self, filename, delim=':', usernameField=0, passwordField=1, caseSensitive=True, hash=None): """ @type filename: C{str} @param filename: The name of the file from which to read username and password information. @type delim: C{str} @param delim: The field delimiter used in the file. @type usernameField: C{int} @param usernameField: The index of the username after splitting a line on the delimiter. @type caseSensitive: C{bool} @param caseSensitive: If true, consider the case of the username when performing a lookup. Ignore it otherwise. @type passwordField: C{int} @param passwordField: The index of the password after splitting a line on the delimiter. @type hash: Three-argument callable. @param hash: A function used to transform the plaintext password received over the network to a format suitable for comparison against the version stored on disk. The arguments to the callable are the username, the network-supplied password, and the in-file version of the password. """ self.filename = filename self.delim = delim self.ufield = usernameField self.pfield = passwordField self.caseSensitive = caseSensitive self.hash = hash if self.hash is None: # The passwords are stored plaintext. We can support both # plaintext and hashed passwords received over the network. self.credentialInterfaces = ( credentials.IUsernamePassword, credentials.IUsernameHashedPassword ) else: # The passwords are hashed on disk. We can support only # plaintext passwords received over the network. self.credentialInterfaces = ( credentials.IUsernamePassword, ) def _cbPasswordMatch(self, matched, usernameAndPassword): ## Return both the username and password so we can save the password ## for connecting to other services once we are authenticated on one. if matched: return usernameAndPassword else: return failure.Failure(error.UnauthorizedLogin()) def getUser(self, username): try: f = file(self.filename) except: log.err() raise error.UnauthorizedLogin() else: if not self.caseSensitive: username = username.lower() for line in f: line = line.rstrip() parts = line.split(self.delim) if self.ufield >= len(parts) or self.pfield >= len(parts): continue if self.caseSensitive: if parts[self.ufield] != username: continue elif parts[self.ufield].lower() != username: continue return parts[self.ufield], parts[self.pfield] raise KeyError(username) def requestAvatarId(self, c): try: u, p = self.getUser(c.username) except KeyError: return failure.Failure(error.UnauthorizedLogin()) else: up = credentials.IUsernamePassword(c) if self.hash: if up is not None: h = self.hash(up.username, up.password, p) if h == p: return (u, p) return failure.Failure(error.UnauthorizedLogin()) else: ## Note that we pass both the username and the password return defer.maybeDeferred(c.checkPassword, p ).addCallback(self._cbPasswordMatch, (u,p))

2 2

[Twisted-Python] Why classes in twisted.protocols.basic use "static member" to store states?
by 甜瓜 30 Mar '07

30 Mar '07

Hi, I'm a newbie. After went through the source code in twisted.protocols.basic, I found it's really strange that all classes in twisted.protocols.basic use "static member" to store states. Take class StatefulStringProtocol as the example. Some Factory will creates a group of StatefulStringProtocol instances which share the static member "state". But why all instances MUST have the same state? In my opinion, instance A may be in the "handshaking" state, while instance B may be in the "data sending" state. The static member can not represent this case. Therefore, I think protocols should use "member variable" rather that "static member": class StatefulStringProtocol: def __init__(self): self.state = 'init' ... Could you plz give me some clue? I am a little confused. Most possibly, I misunderstanding the design about protocols-factory. Thank you. ShenLei

5 6

[Twisted-Python] Simultaneous Blocking Operations and Twisted
by Matthew Glubb 30 Mar '07

30 Mar '07

Hi All, I am new to twisted and python. I am evaluating the possibility of using it for an application that I am writing. The framework looks very comprehensive (I am also enjoying the python language :) but I have some questions regarding deferred objects and the twisted web server itself. My application essentially comprises the following: 1. HTTP request is received by the server. 2. Server creates a listening socket on an arbitrary port and waits for n seconds for incoming data 3. Data (or timeout message) is returned to the client by way of the HTTP response. This is a relatively simple application and I have created a prototype in PHP with fastcgi. I am well aware of the limitations of PHP when it some to asynchronous events. The application needs to service thousands of clients simultaneously. In terms of CPU power, this is not a problem, the logic is simple and there is little overhead having thousands of listening sockets waiting for data (I'd prefer to use epoll but select or poll will do). However, there is a massive memory overhead because it is necessary to ensure that there is always one, idle process for any incoming request. Given that the request may wait for up to n seconds before returning a response, the number of simultaneous PHP fastcgi processes that are required is unreasonably high. I have toyed with the idea of writing a small (low memory) binary that will accommodate my needs, but my C isn't great, hence twisted. I was wondering whether it is feasible to use the twisted framework for this application. I have been playing with the framework and I can't see a way to service what are essentially thousands of requests that perform blocking operations simultaneously. I have noted the twisted documentation on threads but I was hoping, for the sake of my sanity, that I might be able to manage this using an asynchronous approach. Essentially, what I think I am looking for is a waitFor() on a deferred callback. As an aside, is it possible to compile platform specific python applications as small binaries? Or does the interpreter (is it required?) mean the memory consumption is prohibitive? Can anybody offer any advice on the matter? Thanks a lot :) Matthew Glubb

3 4

[Twisted-Python] anyway to know client address in XMLRPC?
by wang wei 29 Mar '07

29 Mar '07

hello, I need to know the client address connected to my Twisted XMLRPC server, is there any way? the fellow code couldn't work in my machine. class Examle(xmlrpc.XMLRPC): """An example object to be published.""" def _getPeerAddress(self): return self.request.getClientIP() def render(self, request): self.request = request xmlrpc.XMLRPC.render(self, request) the result is said: "C:\Python24\lib\site-packages\twisted\web\server.py:272: UserWarning: Warning! r equest.finish called twice. http.Request.finish(self)" then how can I get client address in twisted?

2 2

[Twisted-Python] 2 threads questions
by Jonathan Vanasco 28 Mar '07

28 Mar '07

i have a threaded daemon which occasionally hangs because of some stalling in the threadpool a- whats the best way to shut it down ? attempts to ctl-c / kill it seem to be interpreted by a random thread. the only way to kill it is a kill -9 the python threading docs said that was the expected behavior, and that it could be avoided by using signal. I figured twisted might have something in it already to handle shutting down a reactor with active threads. the threads docs for twisted are a little light. b- i'm trying to figure out the cause of the stalling in the threadpool from the status messages i'm printing, I'm seeing the main python code firing fine, but the threadpool is just stuck - nothing dispatched to it seems to clean up i wonder if it might be related to a few tickets i've seen http://twistedmatrix.com/trac/ticket/2448 http://trac.edgewall.org/ticket/3923 i'm trying to figure out a way to reliably test this. i've got a ssh manhole running via conch ( and instructions from the twisted book ) can anyone suggest a good way to test and try to debug what is going on? i'm extremely uninformed when it comes to python threads.

2 2

[Twisted-Python] problem with a tutorial
by Rob Smith 28 Mar '07

28 Mar '07

I'm hoping this is just a simple configuration problem I have. I followed the tutorial for Using the Twisted Application Framework and created the .tac file shown below: from twisted.application import internet, service from qotdfactory import QOTDFactory port = 7001 factory = QOTDFactory() application = service.Application("qotd") echoService = internet.TCPServer(port, factory) echoService.setServiceParent(application) As soon as I run it with twistd on my winXP laptop it fails with an Import error "no module named qotdfactory". qotdfactory.py exists in the same directory as the .tac file. If I take the code in the .py file and put it directly in the .tac file, the program runs without trouble. I've tried adding the directory both files are in to the windows path variable, and tried adding a __init__.py file to the directory. Neither made a difference. Any thoughts on what I'm missing? Thanks, Rob Smith ____________________________________________________________________________________ Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/features_spam.html

3 3