Mailman 3 April 2013 - Twisted

[Twisted-Python] GSOC 2013 Project Idea for Twisted Matrix
by Chitrank Dixit 26 Apr '13

26 Apr '13

Good Evening Twisted Matrix is a great module for Networking and I would like to work with this project. I want to propose Twisted a new Idea of Promoting the project to Porting to Python 3 (with backward compatibility). Porting benefits by grabbing the Python 3 users and would prepare the Twisted for the Future. P.S. : I am not sure if this project idea is suitable for Google Summer of Code. *Regards * *Chitrank Dixit * *IIPS-DAVV * *MCA * *trackleech.blogspot.in*

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[Twisted-Python] Lore2sphinx current status
by Kevin Horn 25 Apr '13

25 Apr '13

Someone asked me off-list recently about how to help out with the Lore2Sphinx project. My response seemed like it would be generally helpful to anyone interested, and long enough that I wouldn't want to write it again, so I'm posting most of it here, for anyone else that is interested. ==== The "current" version of lore2sphinx is here: https://bitbucket.org/khorn/lore2sphinx This is the version that is currently being used by the Twisted project in the documentation buildbot. However, it is brittle, and hard to modify, and in general doesn't do some things very well. It also hasn't been updated in some time. I consider it to be in stasis for the time being. Some time ago I forked that repo into this one: https://bitbucket.org/khorn/lore2sphinx-ng The plan for the NG branch is to: a) split out the rendering of reStructuredText into a separate library. That library has it's own repo here: https://bitbucket.org/khorn/rstgen Eventually I'd like for this library to be useful for any tool which wants to emit reStructuredText. The idea is that code using this library will create a tree of document elements, and each of which knows how to render itself into reST. Then you call the .render() element on the root element in that tree, and you get back some reST. (the old/current version just created a bunch of strings and munged them together, which has caused all kinds of ugliness) b) rewrite/adapt lore2sphinx to use rstgen to generate reST c) clean up and extend command-line handling to make it easier to use lore2sphinx in different use-cases. For example, in the old/current version it was impossible to only convert a single file, or a single directory. You had to convert an entire Sphinx project all at once. This was pretty annoying and (I think) has been fixed now. Any future development should be handled on the lore2sphinx-ng "branch" and/or the rstgen repo (both mentioned above). Stuff that needs to be done: 1) Rstgen needs to support a few more core reST element types (by which I mean the ones supported in vanilla docutils). The one that comes to mind immediately is tables. There is some table support in the old/current version of lore2sphinx, which it might be possible to adapt. I haven't started on tables in the new version at all. 2) Rstgen could use some "convenience" elements, for example, elements for specific directives, rather than just using the generic directive element all the time. 3) I'd like Rstgen to also have specific support for generating Sphinx-specific elements, but I haven't started on this. Probably most of these will be subtypes of the document element types already present in rstgen. Examples include sphinx-specific directives, etc. 4) Rstgen needs to have some sort of Document object which represents an individual document, and has the ability to organize things like footnotes, citations, etc. There's a stub for this, but, like a platypus, it doesn't do much. 5) clean up cruft and abandoned code in the lore2sphinx-ng repo. There's a lot of it. 6) Finish re-writing the lore2sphinx code which generates rstgen elements. Some code for this is there already, but obviously there isn't anything for the elements that rstgen doesn't handle yet. Also, some of the code that is there isn't specific enough, and doesn't yet accurately represent the way that lore elements should be interpreted. The old lore2sphinx code which used strings does a pretty good job of this, I think, and is still in the repo, AFAICR (I did mention cruft, right?), so you might take a look at that for more details. -- Kevin Horn

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[Twisted-Python] Coursera course on network design patterns
by Craig Rodrigues 25 Apr '13

25 Apr '13

Hi, In this posting: http://twistedmatrix.com/pipermail/twisted-python/2012-November/026324.html I mentioned that Professor. Douglas C. Schmidt is teaching a Coursera course: "Pattern-Oriented Software Architectures for Concurrent and Networked Software" This course is going on right now: https://www.coursera.org/course/posa There are a lot of very good video lectures in this course. There are also several programming assignments. Students are allowed to implement the programming assignments in whatever language they want. People are submitting assignments in Java, C++, Python, Ruby, Scala. For the students who wish to program in Python, I have been pushing students to look at Twisted on the course discussion board. I have also asked Prof. Schmidt to take assignment 3 for the course, and add special wording for Twisted. The assignment 3 targeted at Twisted is here: https://class.coursera.org/posa-001/human_grading/view/courses/970268/asses… If there are some people in the Twisted community with some free time who can help, can you please join the course (it is free) and provide feedback on the wording of the assignment? It would help to correct any mistakes, and point people to the correct sections of the Twisted documentation. Since you need to join the class to see the wording of the assignment, I am attaching it here. This is a good opportunity to promote Twisted to new students who want to use Python, but also learn how to implement network design patterns Thanks. -- Craig

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[Twisted-Python] Speed of twisted on Amazon EC2
by Tom van Neerijnen 24 Apr '13

24 Apr '13

Hi all I recently wrote a hello world HTTP app in Twisted, Cyclone, node, Go and Scala on the Play framework, and used a combination of ab and gattling to see how fast each was on an m1.small instance on Amazon EC2. I also tested it on bare metal (my laptop:)) but I'll get to that later. The code I used for twisted was the web server code sample from the front page of twistedmatrix.com with the numberRequests increment dropped and a simple "Hello World!" returned instead. For cyclone I used the sample code from the cyclone docs with the same string being returned. Node was the sample from their front page. Play and Go I've never worked with before so those were copy pastes from various examples on their pages but again same URI and return string as the other frameworks. >From one m1.small to another, Go, Play and node were handling about 1.5k requests per second while Twisted and Cyclone were only handling 400-500 requests per second. On loopback from the same m1.small I suspect I was starting to load test the load testers more than the apps but locally all the frameworks were performing similarly. Load testing from another machine to my laptop I was seeing far better performance from Twisted and Cyclone, both doing closer to 2k requests per second. The other frameworks were only a little quicker but again, there's a chance the machine running the load tests was the bottle neck. These tests were very unscientifically done but I still wasn't expecting to see such a big difference between specifically node and Twisted. 500 req/sec is plenty quick for 90% of what I do and of course I know there's so much more to an application than returning hello world but I was wondering if I was missing some trick to speed Twisted up to get close to the others on EC2.

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[Twisted-Python] question : txdbus and dbus-send
by bino＠indoakses-online.com 24 Apr '13

24 Apr '13

Dear All I take https://github.com/cocagne/txdbus/blob/master/doc/tutorial_examples/simple_… and save it to /home/bino/Documents/mbink/pythons/coretac/dbus00.py bino@bino-pata:~$ ls -la /home/bino/Documents/mbink/pythons/coretac |grep dbus -rwxrwxr-x 1 bino bino 1026 Apr 22 12:08 dbus00.py It's work as expected when 'called' using https://github.com/cocagne/txdbus/blob/master/doc/tutorial_examples/simple_… Now I need to callable using dbus-send I wrote '/usr/share/dbus-1/services/org.example.service' as : [D-BUS Service] Name=org.example.MyObjPath Exec=/home/bino/Documents/mbink/pythons/coretac/dbus00.py I try to call : dbus-send --system --print-reply \ --type=method_call \ --dest='org.example.MyObjPath' '/org/example/MyObjPath' \ org.example.MyObjPath.exampleMethod string:'MYTEXT' But I got error msg : Error org.freedesktop.DBus.Error.ServiceUnknown: The name org.example.MyObjPath was not provided by any .service files Kindly please give me any enlightenment sincerely -bino-

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[Twisted-Python] Outreach For Women
by chandrika parimoo 22 Apr '13

22 Apr '13

Hi, i am a second year IT Undergraduate from Pune institute of Computer Technology, India. I came across the Program Outreach For Women and i went through the ideas list of Twisted. I am very keen on working on the project as I have experience of programming in Python. Looking forward for more details. Thanks :)

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[Twisted-Python] twisted.conch.checkers.SSHPublicKeyDatabase validate signature data
by Adi Roiban 22 Apr '13

22 Apr '13

Hi, In RFC 4252 http://www.ietf.org/rfc/rfc4252.txt for The Secure Shell (SSH) Authentication Protocol at section 7. Public Key Authentication Method: "publickey" There is the following information about SSH public key signature. The value of 'signature' is a signature by the corresponding private key over the following data, in the following order: string session identifier byte SSH_MSG_USERAUTH_REQUEST string user name string service name string "publickey" boolean TRUE string public key algorithm name string public key to be used for authentication When the server receives this message, it MUST check whether the supplied key is acceptable for authentication, and if so, it MUST check whether the signature is correct. The current code check that key is accepted for authentication and it also verifies if signature is correct. It does not check that session the format of the signed data, especially if session identifier from signed data is the same as the session of the the current SSH transport session. ----- I also found this document describing how ssh public key authentication works, but it differes from the current conch.ssh userauth.py implementation... maybe it is for SSH v1 http://www.unixwiz.net/techtips/ssh-agent-forwarding.html#chal ------ Shouldn't twisted.conch.checkers.SSHPublicKeyDatabase also check that session id from signed data match the one from transport session? Maybe it does but I am not looking at the right place. I see that in conch/checkers.py line 167 https://github.com/tomprince/twisted/blob/trunk/twisted/conch/checkers.py#L… there is this check, which once signature is valid it just returns avatar_id: if pubKey.verify(credentials.signature, credentials.sigData): return credentials.username Thanks! -- Adi Roiban

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 21 Apr '13

21 Apr '13

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[Twisted-Python] GSoC Project Proposal
by Max Haarhaus 20 Apr '13

20 Apr '13

So I have submitted and updated a patch here: http://twistedmatrix.com/trac/ticket/5228 And I was wondering about writing the project proposal. I'm interested in the Deferred Cancellation idea, but not married to it. The GSoC page says that the proposal should be written with a mentor from Twisted. Is that still true? If not, are there any particular things you're looking for in the proposal, other than what's listed by Google in the requirements? Thanks a lot, Max Haarhaus

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[Twisted-Python] Improved StandardIO support in Windows
by John Popplewell 20 Apr '13

20 Apr '13

Hi all, I've recently put together a series of patches and new files that expand upon and improve the work done in Ticket #2157 http://twistedmatrix.com/trac/ticket/2157 I've got working cftp.py and conch.py scripts and imap4client.py also works. The console support works on a Windows-7 buildbot and acts like a normal console with a flashing cursor and working scroll-back (no editing yet, but back-space works). I missed exarkun's message until after I'd uploaded the patches there :( As I got familiar with the code-base again (I was using some of this stuff on windows over 5 years ago), I looked at lots of tests that could be enabled now, and have a set of other patches for more tests (I got up to 6999 :) Not sure how to proceed so I'm doing as exarkun suggested, and posting here, best regards, John Popplewell PS I married a beautiful American woman last year and now reside in Northern Michigan - looking for work, thought I'd try and do something useful.

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