Mailman 3 May 2015 - Twisted

[Twisted-Python] INCOMPATIBLE CHANGE: Removing PAM support from Twisted
by HawkOwl May 11, 2015

May 11, 2015

As per https://twistedmatrix.com/trac/wiki/CompatibilityPolicy#ProcedureforExcepti…: Twisted's PAM support is reliant on a library which a) doesn't materially exist anymore, b) is blocking, c) is uninstalled on all our buildbots if I'm correct and so therefore hasn't been tested for ages, and d) requires us to do insecure things (like setting euid as root). Since it's basically uninstallable (I can't even find a source tarball newer than 1999) and almost certainly doesn't work on any Python … [View More]

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[Twisted-Python] LoopingCall.withCount countCallable called with 0
by Dario Vinella May 10, 2015

May 10, 2015

Hi all, I found an odd behavior using a LoopingCall.withCount with a very small interval (0.02 sec): sometimes the countCallable is called with 0 as argument and it looks like the now - _realLastTime is smaller than the looping interval. Here you can find the very simple code I use to reproduce the "anomaly", with a main loopingCall and another one that prints its internals https://gist.github.com/dvinella/31d94f9dd0e47586658d and here an extract of the logs it produces https://gist.… [View More]

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com May 10, 2015

May 10, 2015

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[Twisted-Python] New Supported Platforms - Python 3.3 and Python 3.4 on Debian 7
by HawkOwl May 8, 2015

May 8, 2015

Hi everyone! I'm pleased to announce that Twisted will have one more new supported Python version (3.4) as of Twisted 15.2. The debian7-py33 and debian7-py34 builders will shortly be moving from 'unsupported' to 'supported'. - Hawkie

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[Twisted-Python] Crochet 1.4.0: use Twisted anywhere!
by Itamar Turner-Trauring May 6, 2015

May 6, 2015

Crochet is an MIT-licensed library that makes it easier to use Twisted from regular blocking code: from __future__ import print_function from twisted.names import client from crochet import setup, wait_for setup() @wait_for(timeout=5.0) def gethostbyname(name): """Use the Twisted DNS library.""" d = client.lookupAddress(name) d.addCallback(lambda result: result[0][0].payload.dottedQuad()) return d if __name__ == '__main__': # Application code using the public API - … [View More]

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[Twisted-Python] can QtWebKit fire a twisted deferred?
by Kevin Mcintyre May 6, 2015

May 6, 2015

''' I know this is meant for pyqt but I've had little luck this that board. The short answer is yes, but it's a total hack...and I'm wondering if anybody has a more elegant solution. Specifically I would like to be able to fire a defer from the javascript instead of having to call alert. Below is an example of how I currently gain access...not necessarily a working version. ''' url = 'http://www.google.com' mo = """ var observer = new MutationObserver(function(mutations) { … [View More]

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[Twisted-Python] Fwd: Adding callbacks using loop variables
by Saoili May 6, 2015

May 6, 2015

Hi folks, I was going to ask a question, but a colleague resolved it for me. I thought I'd share the result! We often end up using lambda to add callbacks, especially where we want to pass the response to a deferred into a function and it's not the first parameter. However, if you do that inside a loop and one of the variables you're passing is a loop variable, you're going to get the same value for that loop variable in all of your callbacks (the last one). The solution is to avoid calling … [View More]

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[Twisted-Python] buildbot celebration!
by Glyph Lefkowitz May 5, 2015

May 5, 2015

Thanks to the efforts of Adi Roiban and HawkOwl, we now have our first 100% supported green trunk run in a while: https://buildbot.twistedmatrix.com/boxes-supported?branch=trunk&num_builds=… Care and feeding for the build farm is an often thankless and invisible job; things can often start failing for irrelevant reasons outside of changes to Twisted and it requires work to get it back on track and keep our quality where it should be, so I just wanted to call it out specifically and say … [View More]

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Re: [Twisted-Python] Twisted-Python Digest, Vol 132, Issue 23
by Timothy Gallagher May 5, 2015

May 5, 2015

Glyph I just saw this response in my junk mail. Thank you for the help, I can work with this. Tj -----Original Message----- From: twisted-python-bounces(a)twistedmatrix.com [mailto:twisted-python-bounces@twistedmatrix.com] On Behalf Of twisted-python-request(a)twistedmatrix.com Sent: Friday, March 20, 2015 1:26 AM To: twisted-python(a)twistedmatrix.com Subject: Twisted-Python Digest, Vol 132, Issue 23 Send Twisted-Python mailing list submissions to twisted-python(a)twistedmatrix.com To … [View More]subscribe or unsubscribe via the World Wide Web, visit http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python or, via email, send a message with subject or body 'help' to twisted-python-request(a)twistedmatrix.com You can reach the person managing the list at twisted-python-owner(a)twistedmatrix.com When replying, please edit your Subject line so it is more specific than "Re: Contents of Twisted-Python digest..." Today's Topics: 1. custom FTP server is blocking (Paul Wiseman) 2. Re: custom FTP server is blocking (Louis D. Burr) 3. Re: __nonzero__ for Deferred (Glyph Lefkowitz) 4. Re: Removing Python 2.6 Support after Twisted 15.1 (David Ripton) 5. Re: twistechecker and twisted-dev-tools as part of twisted main repo (Glyph) 6. Re: twisted echo ssl client with .p12 (Glyph) ---------------------------------------------------------------------- Message: 1 Date: Thu, 19 Mar 2015 18:18:27 +0000 From: Paul Wiseman <poalman(a)gmail.com> To: Twisted general discussion <twisted-python(a)twistedmatrix.com> Subject: [Twisted-Python] custom FTP server is blocking Message-ID: <CACgdh2i4n5CgwiOQ124YeM-Cyqp+3rMwHGFN7cnq5dt=C_Ne0A(a)mail.gmail.com> Content-Type: text/plain; charset=UTF-8 I have some blocking going on in a custom twisted ftp server and I'm trying to pin point what exactly is doing it. I think this line in openForReading on my FTPShell object could be the culprit: _FileReader(urllib2.urlopen(result.link,timeout=settings.GLOBAL_TIMEOUT)) (_FileReader is twisted.protocols.ftp._FileReader and result.link a url string) I'm guessing urllib2.urlopen blocks resolving the domain and connecting? What would be the twisted equivalent way of providing a file like object of the download stream to the FileReader that wouldn't block? Regards, Paul ------------------------------ Message: 2 Date: Thu, 19 Mar 2015 15:38:30 -0500 From: "Louis D. Burr" <ldanielburr(a)me.com> To: Twisted general discussion <twisted-python(a)twistedmatrix.com> Subject: Re: [Twisted-Python] custom FTP server is blocking Message-ID: <3E9E76E8-E3D3-4905-86B1-0003192C2834(a)me.com> Content-Type: text/plain; charset=us-ascii Hi Paul, > On Mar 19, 2015, at 1:18 PM, Paul Wiseman <poalman(a)gmail.com> wrote: > > I have some blocking going on in a custom twisted ftp server and I'm > trying to pin point what exactly is doing it. > > I think this line in openForReading on my FTPShell object could be the culprit: > > _FileReader(urllib2.urlopen(result.link,timeout=settings.GLOBAL_TIMEOU > T)) > Yeah, urllib2.urlopen() blocks, so this is at least one place in your code that will cause you a problem. > (_FileReader is twisted.protocols.ftp._FileReader and result.link a > url string) > > I'm guessing urllib2.urlopen blocks resolving the domain and > connecting? What would be the twisted equivalent way of providing a > file like object of the download stream to the FileReader that > wouldn't block? > You probably want to use twisted.web.client.Agent for this, as it allows you to perform non-blocking http requests. If you can live with buffering the http response body into, say, a tempfile or an io.BytesIO instance, then you can just pass that to _FileReader as the fObj argument and call it a day. Hope this helps, -- L. Daniel Burr ------------------------------ Message: 3 Date: Thu, 19 Mar 2015 14:13:48 -0700 From: Glyph Lefkowitz <glyph(a)twistedmatrix.com> To: Twisted general discussion <twisted-python(a)twistedmatrix.com> Subject: Re: [Twisted-Python] __nonzero__ for Deferred Message-ID: <18084B73-66AE-4F0A-857C-507D27537533(a)twistedmatrix.com> Content-Type: text/plain; charset=us-ascii > On Mar 18, 2015, at 5:50 PM, exarkun(a)twistedmatrix.com wrote: > > On 18 Mar, 10:03 pm, glyph(a)twistedmatrix.com wrote: >> I'd like to deprecate and remove __nonzero__ on Deferreds. Occasionally I see code where someone (maybe even me) does "if d:" where they should have been doing "@d.addCallback def cb(result): if result: ...". >> >> Anybody else have this issue? Objections? > > Er. What? It's a little early for april fools' day, isn't it? > Seriously, this is weird. Am I missing something? Apparently? > Can expand on what it would mean to deprecated a special method of a > class that doesn't even define it Add such a method and cause it to emit a warning, then raise an exception. > and what makes Deferred unique among all user-defined classes in this regard. As I stated in my original message, there's a class of bug where someone does "if somethingThatReturnsDeferred()". Particularly, "if checkPassword()" is a dangerous manifestation of this class of bug. I'd like this to fail noisily instead of appearing to work. In my opinion, having all user-defined classes implement true truthiness by default is a design error in the language. It's a usually-harmless one except in a few cases, and this is one of those cases, which is why Deferred is not the same as the average user-defined class. -glyph ------------------------------ Message: 4 Date: Thu, 19 Mar 2015 20:23:35 -0400 From: David Ripton <dripton(a)ripton.net> To: twisted-python(a)twistedmatrix.com Subject: Re: [Twisted-Python] Removing Python 2.6 Support after Twisted 15.1 Message-ID: <550B6887.4020703(a)ripton.net> Content-Type: text/plain; charset=utf-8 On 03/19/2015 08:05 AM, Phil Mayers wrote: > On 18/03/15 23:57, Glyph Lefkowitz wrote: > >> Rather than just suggest we preserve the status quo and stay on 2.6 >> forever to do indefinite free work to support Red Hat's obsolescence > > You *definitely* shouldn't do that. Push back on RedHat, and tell > customers to push back on RedHat. I say this to other projects. Red Hat supports old versions of RHEL forever because they have customers that want that (because they have legacy apps that they want to keep working with minimal maintenance, but who still want security patches), and are willing to pay for it. It's a good thing that someone provides that option, even if we don't all need it. That doesn't mean Twisted needs to support old versions of RHEL forever. RHEL 7 has been out for a while, and comes with Python 2.7 as the default. So even if Twisted drops support for Python 2.6, it'll still work on RHEL. (Just not on old versions of RHEL.) Furthermore, SCL makes Python 2.7 available (in /opt) on RHEL 5 and 6 and CentOS 6, without users needing to build it themselves. So even those who are stuck with old versions can install SCL, then use pip to install new Twisted. IOW, I wouldn't worry about it. Drop support for Python 2.6 when it makes sense for Twisted. -- David Ripton dripton(a)ripton.net ------------------------------ Message: 5 Date: Thu, 19 Mar 2015 20:25:04 -0700 From: Glyph <glyph(a)twistedmatrix.com> To: Twisted general discussion <twisted-python(a)twistedmatrix.com> Subject: Re: [Twisted-Python] twistechecker and twisted-dev-tools as part of twisted main repo Message-ID: <790710C6-7461-4E4C-A796-381BD3ED2679(a)twistedmatrix.com> Content-Type: text/plain; charset=utf-8 > On Mar 19, 2015, at 8:41 AM, Christopher Armstrong <radix(a)twistedmatrix.com> wrote: > > >> On Mar 19, 2015, at 4:45 AM, Adi Roiban <adi(a)roiban.ro> wrote: >> >>> OK, cool. I didn't realize that was ready for review. I am liking >>> the process we have for Mimic for flagging PRs with keywords - >>> https://github.com/rackerlabs/mimic/pulls - but this needs >>> automation so as not to be unfriendly to non-committer contributors. >>> >>> I'll try to get to it by the end of the week. >> >> For twistedchecker I start using tags ... but I don't have >> permissions for twisted-infra repos. >> >> Yes. GitHub PR are nice but horrible for implementing anything formal >> on top of it. >> >> I was preparing to suggest someting similar also for Trac as >> sometimes I am not sure if a comment is 'do minor changes and merge' >> or 'do minor change and send them for review' >> >> My suggestion is this: >> >> when a PR is ready for review the author should leave a comment >> containing the `needs-review` marker. This will send a hook and a >> custom hook server will update the tags of the ticket. >> > > > I suggest making the default, tagless state of a PR mean ?in review?, for a couple of reasons: > > - having labels for both `needs-changes` and `in-review` means you can > enter an invalid state where both labels are applied > - if the automation loses track of a PR, we don?t want people > filtering only for PRs with `label:in-review` and missing out on the > forgotten PR > > so I propose tagless PRs be considered ?in review?, and a label only for `needs-changes`. I like seeing the big green "ready for review" on Mimic PRs; it's more eye-catching. We can have 2 labels though, so that if the automation breaks, we can have a periodic check that adds "in-review" to everything un-labeled. -g ------------------------------ Message: 6 Date: Thu, 19 Mar 2015 22:25:10 -0700 From: Glyph <glyph(a)twistedmatrix.com> To: Twisted general discussion <twisted-python(a)twistedmatrix.com> Subject: Re: [Twisted-Python] twisted echo ssl client with .p12 Message-ID: <1AE7D177-6F83-4204-B088-3706F7E1B05F(a)twistedmatrix.com> Content-Type: text/plain; charset="us-ascii" > On Mar 19, 2015, at 8:36 AM, Louis D. Burr <ldanielburr(a)me.com> wrote: > > Hi Timothy, > >> On Mar 19, 2015, at 9:56 AM, Timothy Gallagher <timothy.gallagher(a)nuspire.com <mailto:timothy.gallagher@nuspire.com>> wrote: >> >> Hello all, >> I have a project that requires client server with ssl/tls including client certificate authentication. Also the a requirement is that the client needs to use a .p12 file to house its keys. I have the server part and client part down except I cannot find any code examples using a .p12 file to get the certificates. Can this be done without having to hack into the ssl.ClientConextFactory? > > Maybe http://stackoverflow.com/questions/6345786/python-reading-a-pkcs12-certific… <http://stackoverflow.com/questions/6345786/python-reading-a-pkcs12-certific…> will be useful to you. Twisted uses pyopenssl under the covers, so the solution exarkun posted to StackOverflow should be applicable. > > Hope this helps, > > - L. Daniel Burr You definitely shouldn't use ssl.ClientContextFactory. It doesn't verify certificates, or provide any authentication of the server. We should really remove and deprecate it :-\. You should use ssl.optionsForClientTLS, and you should build it like this: import getpass from OpenSSL.crypto import load_pkcs12 from twisted.internet.ssl import ( PrivateCertificate, KeyPair, Certificate, optionsForClientTLS ) from twisted.internet.protocol import Factory, Protocol from twisted.internet.endpoints import SSL4ClientEndpoint from twisted.internet.defer import inlineCallbacks, Deferred from twisted.internet.task import react @inlineCallbacks def main(reactor, p12file, host, port=443): host = host.decode("utf-8") port = int(port) with open(p12file) as f: pkcs12 = load_pkcs12(f.read(), getpass.getpass()) publicCertificate = Certificate(pkcs12.get_certificate()) privateKey = KeyPair(pkcs12.get_privatekey()) privateCertificate = PrivateCertificate.fromCertificateAndKeyPair( publicCertificate, privateKey ) contextFactory = optionsForClientTLS(host, clientCertificate=privateCertificate) endpoint = SSL4ClientEndpoint(reactor, host, port, contextFactory) x = Deferred() class it(Protocol, object): def connectionMade(self): self.transport.write(b"GET / HTTP/1.1\r\n\r\n") def dataReceived(self, data): x.callback(Certificate.peerFromTransport(self.transport)) self.transport.abortConnection() yield endpoint.connect(Factory.forProtocol(it)) cert = yield x print(cert) from sys import argv react(main, argv[1:]) Hopefully that's a pretty complete answer :-). -glyph [View Less]

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[Twisted-Python] twisted ldaptor
by the2nd＠otpme.org May 5, 2015

May 5, 2015

Hi all, i just want to ask if this is the correct list to ask questions about https://github.com/twisted/ldaptor. regards the2nd

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[Twisted-Python] Urgent - reactor is not working out of a sudden
by Jessica Tsui May 3, 2015

May 3, 2015

I was working on my program and everything was fine, out of the blue the python editor just told me that connectTCP and listenTCP cannot be referenced in reactor.py. I tried to reinstall twisted but that didn't help at all. How could I solve this?

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com May 3, 2015

May 3, 2015

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[Twisted-Python] sorry about the win7 builder
by Glyph May 1, 2015

May 1, 2015

Looks like the win7 builder went offline while I wasn't paying attention. I've gotten it security-updated and launched again, and it is presently chewing through the backlog on https://buildbot.twistedmatrix.com/builders/windows7-64-py2.7 <https://buildbot.twistedmatrix.com/builders/windows7-64-py2.7> - it should be current in a couple of hours. -glyph

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[Twisted-Python] flushing data to clients after a global variable is updated in server
by Jessica Tsui April 30, 2015

April 30, 2015

Hi, it's me again. I am still working on the kivy app, and now I am trying to add a function to the app - the server side has two seconds to decide if he wants to alter the original data sent from one client to other clients. If he would like to do so, he has to press a button. If he does not press the button in 2 seconds, the original data will be sent to other clients automatically. Right now I am trying to achieve that with the following code - by calling the MultiClientEcho().dataReceived(… [View More]msg, "censored") line in the function as if MultiClientEcho received another data, however once i click the button, the program crashed and said (MultiClientEcho().dataReceived(msg, "censored") TypeError: __init__() takes exactly 3 arguments (1 given)) I wonder how can I fix this and achieve the function I am aiming at? import kivy from kivy.app import App from kivy.uix.label import Label from kivy.uix.scatter import Scatter from kivy.uix.boxlayout import BoxLayout from kivy.uix.scrollview import ScrollView from kivy.uix.button import Button from kivy.graphics.vertex_instructions import Rectangle from kivy.graphics.context_instructions import Color from kivy.graphics.instructions import Instruction from kivy.base import runTouchApp from kivy.lang import Builder import socket from kivy.core.window import Window import pygame import random from kivy.support import install_twisted_reactor install_twisted_reactor() from twisted.internet import protocol, defer from time import sleep from twisted.internet import reactor, task from twisted.protocols.basic import LineReceiver from twisted.internet.protocol import Protocol, Factory censored = 0 class MultiClientEcho(protocol.Protocol): def __init__(self, factory, app): self.factory = factory self.app = app def connectionMade(self): self.factory.clients.append(self) def dataReceived(self, data): storedmessage = self.factory.app.handle_message(data) global censored def f(data): for client in self.factory.clients: client.transport.write(data) print "this will run in 1 sec after it's scheduled: %s" % data if censored == 0 and storedmessage: reactor.callLater(2, f, data) # client.transport.write(data) elif censored == 1: reactor.callLater(0, f, 'censored') censored == 0 def connectionLost(self, reason): self.factory.clients.remove(self) class MultiClientEchoFactory(protocol.Factory): protocol = MultiClientEcho def __init__(self, app): self.clients = [] self.app = app def buildProtocol(self, addr): return MultiClientEcho(self, self.app) class ServerApp(App): def build(self): self.label = Label(text="server started\n") self.approve_btn = Button(text="approve") # self.approve_btn.bind(on_release=self.send_message) self.banned_btn = Button(text="banned") self.banned_btn.bind(on_release=self.banned_message) self.layout = BoxLayout(orientation='vertical', spacing=10) reactor.listenTCP(8000, MultiClientEchoFactory(self)) self.layout.add_widget(self.label) self.layout.add_widget(self.banned_btn) return self.layout def banned_message(self, msg): global censored censored = 1 self.label.text += "censored\n" MultiClientEcho().dataReceived(msg, "censored") print censored return censored def handle_message(self, msg): self.label.text += "%s\n" % msg return msg if __name__ == '__main__': ServerApp().run() for i in range(0,1): print 1-i sleep(0.1) [View Less]

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