Mailman 3 July 2010 - Twisted

[Twisted-Python] What is the minimum effort solution to make inetd-managed twisted-based application?
by twisted-web＠udmvt.ru July 29, 2010

July 29, 2010

What is the minimal effort method for building protocol instance (maybe out of already implemented protocol factory) using a transport, that uses parent-inherited sockets (or any other already connected sockets) ? I haven't yet found any single-line solution for that. For example, how to start an inetd-managed SMTP server (with STARTTLS support), suppose, we have protocol (and factory) already implemented, but how to construct the correct transport out of fd with the minimal effort? Or how to implement ucspi-tcp's tcpclient client on top of twisted framework? Right now I am looking at t.i.unix.Connector and t.i.unix.Port to understand how do transports get constructed by them, but well, that is too complex for a single evening. Should I really get into the details of implementing my own transport (or their constructors) to do what I need? I'm sure there should be something, that I missed in the documentation (or in the code?). And by the way, I haven't found any socketpair(2) usage in the twisted framework (except for tests), how can that be? Transport based on socketpair sockets will have the same implementation, as I need. Is it true, that nobody in twisted community uses anonymous preconnected sockets in real life? PS: I need socket-based transport, that is, full-duplex, half-closeable, with support of getting the remote endpoint address and with ability to start TLS on top of it and without implementing every that feature myself :) Thanks for a great framework! Alexey. -- с уважением, Алексей Шпагин системный администратор цеха передачи данных технического центра телекоммуникаций ОАО "ВолгаТелеком" филиал в Удмуртской республике.

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[Twisted-Python] Using zeromq inside twisted matrix daemon
by Uung H.R Bhuwono July 28, 2010

July 28, 2010

Hi, I've been trying to make use zeromq on my twisted daemon script When zeromq send message to the queue, this work since send_pyobj() return True. But the subscriber never get the message from queue using recv_pyobj() and it just freeze like there's nothing on the queue My twisted daemon script as a follow: - serve_message.py class MyService(service.Service): def __init__(self): pass def startService(self): c = zmq.Context(1) s = c.socket(zmq.PUB) s.bind("tcp://127.0.0.1:6666") s.send_pyobj("helo there") def stopService(self): pass def getMyService(): myService = MyService() return myService application = service.Application("My Service Application") # attach the service to its parent application procd = getMyService() procd.setServiceParent(application) my simple subscriber script subscriber.py import zmq c = zmq.Context(1) s = c.socket(zmq.SUB) s.connect("tcp://127.0.0.1:9999") s.setsockopt(zmq.SUBSCRIBE, "") s.recv_pyobj() Does it possible to use zeromq with twisted daemon on Linux? Please help me to solve this Thanks, Uung

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[Twisted-Python] SMTP Client Blocking Connects
by Jason J. W. Williams July 27, 2010

July 27, 2010

Hi Guys, Are TCP connects in Twisted usually blocking? Noticing a behavior when I've got several simultaneous SMTP client objects operating, where when one of them hits a server that times out on the connect...the program blocks until the connect times out. Everything else is working async/non-blocking as expected. -J

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[Twisted-Python] How to make a 'router'
by Didiet Noor July 25, 2010

July 25, 2010

Dear All, I am new in twisted framework, and currently building a twisted app that will route a packet from one client to multiple servers via TCP connection, back and forth. The program will work like this /----> server A Client --> twisted routing apps ----> server B \----> server C I also wrote the server apps using twisted by using simple Int32StringReceiver. I haven't made this kind of application before. So could you guys give me pointers on how to do that? Thanks in advance, LynxLuna

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com July 25, 2010

July 25, 2010

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[Twisted-Python] Client/Server upload problem
by Sean Dugan July 22, 2010

July 22, 2010

I can't seem to figure out how a client uploads a file to the server using twisted.protocols.ftp. For the server side I am using the ftpserver example from the twisted website. For the client I have the following: from twisted.protocols.ftp import FTPClient, FTPFileListProtocol from twisted.internet.protocol import Protocol, ClientCreator from twisted.python import usage from twisted.internet import reactor from twisted.protocols.basic import FileSender # Standard library imports import string import sys try: from cStringIO import StringIO except ImportError: from StringIO import StringIO class BufferingProtocol(Protocol): """Simple utility class that holds all data written to it in a buffer.""" def __init__(self, fileToWrite): self.buffer = StringIO() self.fileToWrite = fileToWrite def dataReceived(self, data): self.buffer.write(data) # Define some callbacks def success(response): print 'Success! Got response:' print '---' if response is None: print None else: print string.join(response, '\n') print '---' def fail(error): print 'Failed. Error was:' print error def showFiles(result, fileListProtocol): print 'Processed file listing:' for file in fileListProtocol.files: print ' %s: %d bytes, %s' \ % (file['filename'], file['size'], file['date']) print 'Total: %d files' % (len(fileListProtocol.files)) def showBuffer(result, bufferProtocol): print 'Got data:' print bufferProtocol.buffer.getvalue() def writeBufferToFile(result, bufferProtocol): f = open(bufferProtocol.fileToWrite, 'w') f.write(bufferProtocol.buffer.getvalue()) f.close() class Options(usage.Options): optParameters = [['host', 'h', 'localhost'], ['port', 'p', 21], ['username', 'u', 'anonymous'], ['password', None, 'bozo'], ['passive', None, 0], ['debug', 'd', 1], ] def run(): # Get config config = Options() config.parseOptions() config.opts['port'] = int(config.opts['port']) config.opts['passive'] = int(config.opts['passive']) config.opts['debug'] = int(config.opts['debug']) # Create the client FTPClient.debug = config.opts['debug'] creator = ClientCreator(reactor, FTPClient, config.opts['username'], config.opts['password'], passive=config.opts['passive']) creator.connectTCP(config.opts['host'], config.opts['port']).addCallback(connectionMade).addErrback(connectionFailed) reactor.run() def connectionFailed(f): print "Connection Failed:", f reactor.stop() def fileTransferFail(failure): failure.printTraceback() reactor.stop() def cbStore(consumer, filename): fs = FileSender() d = fs.beginFileTransfer(open(filename, 'r'), consumer) d.addCallback(lambda _: consumer.finish()).addErrback(fileTransferFail) return d def connectionMade(ftpClient): # Get the current working directory ftpClient.pwd().addCallbacks(success, fail) # Get a detailed listing of the current directory fileList = FTPFileListProtocol() d = ftpClient.list('.', fileList) d.addCallbacks(showFiles, fail, callbackArgs=(fileList,)) # Change to the parent directory ftpClient.cdup().addCallbacks(success, fail) filename = "FtpDownload.txt" uploadpath = "FtpUpload.txt" d1, d2 = ftpClient.storeFile(uploadpath) d1.addCallback(cbStore, filename).addErrback(fileTransferFail) d2.addCallback(lambda _: reactor.stop()) # this only runs if the module was *not* imported if __name__ == '__main__': run() When I run this, it returns “Failure: twisted.protocols.ftp.CommandFailed: ['550 FtpUpload.txt: Permission denied']”. I can download a file, and view the files in a folder, I just can't upload a file. Also if I log-in as one the users in the .dat file, instead of anonymous, I can't even view the files in a folder. So is there a way to give anonymous or a user in the .dat file more permissions, like the write permission?

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[Twisted-Python] trial newbie
by Nathan July 22, 2010

July 22, 2010

Okay, so I'm just starting to learn how to use trial (I know, I'm a bad, bad boy), and I'm having trouble getting started. The trial page[1] says "Tests that subclass the standard library TestCase and don't do anything "too weird" should be able to be discoverable and runnable by the Trial test runner without the authors of those tests having to jump through hoops." So I made a small concept file to try that out: =-=-=-=-=-=-=- #!/usr/bin/env python import unittest, sys from distutils import version class TestPrerequsites(unittest.TestCase): def setUp(self): pass def test_00(self): "Supported OS?" self.assertTrue(sys.platform in ['darwin']) if __name__ == '__main__': unittest.main() =-=-=-=-=-=-=- I named it 'test.py' and made sure it worked with python: =-=-=-=-=-=-=- $ python test.py -v Supported OS? ... ok ---------------------------------------------------------------------- Ran 1 test in 0.000s OK =-=-=-=-=-=-=- and then I tried running it in trial under Twisted 8.2.0 on OS 10.6...and it crashed...sorta. A traceback was output, but after the traceback stuff it also seemed to run the test. So I thought, "I probably just need to upgrade." So I upgraded to Twisted 10.1.0 and ran it again. It still crashed...sorta. Here's what it looks like. $ trial test.py Traceback (most recent call last): File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/python/usage.py", line 241, in parseOptions self.postOptions() File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/scripts/trial.py", line 295, in postOptions self['reporter'] = self._loadReporterByName(self['reporter']) File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/scripts/trial.py", line 281, in _loadReporterByName for p in plugin.getPlugins(itrial.IReporter): File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/plugin.py", line 199, in getPlugins allDropins = getCache(package) --- <exception caught here> --- File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/plugin.py", line 178, in getCache dropinPath.setContent(pickle.dumps(dropinDotCache)) File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/python/filepath.py", line 745, in setContent f = sib.open('w') File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/python/filepath.py", line 495, in open return self.create() File "/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/python/filepath.py", line 771, in create fdint = os.open(self.path, _CREATE_FLAGS) exceptions.OSError: [Errno 13] Permission denied: '/Library/Python/2.6/site-packages/Twisted-10.1.0-py2.6-macosx-10.6-universal.egg/twisted/plugins/n8ARdewBqzybvuUpdropin.cache.new' test TestPrerequsites test_00 ... [OK] ------------------------------------------------------------------------------- Ran 1 tests in 0.023s PASSED (successes=1) Anyone know what's going on? I installed/upgraded version 10.1.0 by downloading the tarball and running "sudo python setup.py install" ~ Nathan [1] http://twistedmatrix.com/documents/current/api/twisted.trial.html

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[Twisted-Python] Uses of StringIO instead of cStringIO
by Albert Brandl July 21, 2010

July 21, 2010

Hi! There are several modules in twisted that import StringIO instead of cStringIO (e.g. twisted/mail/maildir.py, twisted/news/nntp.py, twisted/web/script.py). Are there any reasons why they use the slower variant implemented in Python instead of the C variant? If not, I'd like to create a ticket to fix these imports. -- Best regards, Albert Brandl Weiermayer Solutions GmbH Abteistraße 12 A-4813 Altmünster phone: +43 (0) 720 70 30 14 fax: +43 (0) 7612 20 3 56 web: http://www.weiermayer.com

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[Twisted-Python] loading intermediate CA certs from a chain file
by Sury Soni July 21, 2010

July 21, 2010

Hi There, Does Twisted support or is there any way of loading intermediate CA certs from a chain file? I have a SSL certificate issued by Thawte, but my system administrator says as quoted: Looks like you may need to install an Intermediary certificate. Relevant certs for Thawte can be found at https://search.thawte.com/support/ssl-digital-certificates/index?page=conte… I am not sure, how to generate a chain file and later, how to use it in twisted ssl enabled server. At the moment, I am using following line of code: root_ssl_service = internet.SSLServer(443, site_ssl, DefaultOpenSSLContextFactory( privateKeyFileName="cert/server.key", certificateFileName="cert/server.pem")) Thanks in advance. Sury

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Re: [Twisted-Python] [Twisted-web] Mirror Down
by Glyph Lefkowitz July 20, 2010

July 20, 2010

On Jul 19, 2010, at 10:20 PM, exarkun(a)twistedmatrix.com wrote: > On 19 Jul, 01:28 pm, nickpholden(a)gmail.com wrote: >> Hi, >> >> The main mirror for the twisted download is down, this is causing >> easy_install to hang for ages and fail when I try and install: > > For Twisted 10.1, we took the extra step of loading the tarball to PyPI > to address this issue. Apparently that was pointless, though? Because > easy_install doesn't care about the downloads available on PyPI? It'd > be good to know if this is the case, so we can consider whether or not > to waste the time for the next release. As an experiment, I took the _additional_ step of updating the "download_url" field to point at the PyPI URL, <http://pypi.python.org/packages/source/T/Twisted/Twisted-10.1.0.tar.bz2>. Before I did this, easy_install selected the download link from twistedmatrix.com. Now, it reliably selects the PyPI URL first. Looking at the history now, I can see that therve actually updated the download_url to something else already, but now I can't see what he set it to. Maybe it was pointing at "twistedmatrix.com" and that's why it was screen-scraping? I am not sure how to *remove* the download_url, though; it might be interesting to see what PyPI does in that case. Can anyone with some more direct knowledge of how PyPI works comment on this? (Cross-posting to the main Twisted list because this is of general interest.)

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