Mailman 3 August 2005 - Twisted

[Twisted-Python] Accessing shell over a pseudo terminal via conch/ssh Totally lost...
by J French 24 Aug '05

24 Aug '05

I am trying to get access to bash on freebsd from a pty using ssh/conch. I can't find information on this; I've googled for two days now. Seems like something that would be frequently done. I have played with sshsimpleclient.py and it works as advertised but I don't understand how to open a pty for continuous access to the shell. Can anyone shed some light on this for me? Thanks in advance, JF

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[Twisted-Python] Making a Persistent SSH connection w/ Conch - How?
by J French 23 Aug '05

23 Aug '05

I'm trying to design a ssh client that establishes a connection that it persistent until I close it so that I can use it for constant bi-directional communication. I want it to act like a shell with a gui top of it (wxPython). I think I need to keep a channel open continuously to effect this. This is my first attempt at using ssh so I'm probably missing some important paradigms here, please fill me in if possible. I grabbed the the sshsimpleclient.py code from http://twistedmatrix.com/projects/conch/documentation/examples/sshsimplecli… and modified (to test the behavior): def closed(self): print 'got data from cat: %s' % repr(self.data) #self.loseConnection() #reactor.stop() The server connection still closes as soon as I receive the callback data. I'm using freebsd and it works as advertised (I see the connection in auth.log but of course, its closed before I can 'who' and check it out) Any advice on the right way to get started would be appreciated! -John

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[Twisted-Python] FileSender stability.
by Bill Bumgarner 23 Aug '05

23 Aug '05

I'm in need of moving data between various LineReceiver based instances. So far, this has proved to be as easy as sending a line with the # of bytes of raw data to be sent, throwing the receiver into raw mode, and receiving said bytes. No problem. Now I'm about to start sending files between LineReceiver instances. I could certainly do this by writing a bunch of code. Well, not that much code (it seems that most of the challenge of using Twisted is figuring out what code not to write!). However, there is the wonderful class called "FileSender" that seems to do 1/2 of exactly what I need to do; send a file. However, the documentation for the class indicates that it will "at some point" do what I want and that the API is stable. So -- should I bother using the FileSender class or roll my own? thanks, b.bum (BTW: Twisted has to be one of the coolest pieces of software I have worked with in a very, very long time.)

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[Twisted-Python] twistd and SqlObject
by Graham Stratton 23 Aug '05

23 Aug '05

I'm sure the answer to this question should be obvious, but I can't find it. I've written a twisted server which recieves a request, looks up the requested data in its cache, and returns the data. It accesses its database via SQLObject - the database is small, so I don't care that it blocks. Twisted has certainly made this very simple. I now want to run that same process using twistd (-noy), but SqlObject gives the error Failed to load application: 'NoneType' object has no attribute 'tableExists' on the last line of the listing below, which works fine when run normally. I guess I'm being very naive about the way in which twistd works, but I can't find any comprehensive documentation saying what it does. Thanks for any pointers, Graham import _mysql_exceptions from elementtree.ElementTree import Element, SubElement, ElementTree, parse from twisted.internet import reactor from twisted.web import server from twisted.web.resource import Resource from twisted.web.client import getPage from cStringIO import StringIO import sqlobject import datetime now = datetime.datetime.now cacheDurationDays = 90 __connection__ = sqlobject.MySQLConnection(host='localhost', db='DomainInfoCache', user='root', passwd='chubchub') class CachedDomain(sqlobject.SQLObject): """The table that the data is cached in""" domain = sqlobject.StringCol(length=80) alexa3monthtraffic = sqlobject.FloatCol() lastUpdate = sqlobject.DateTimeCol() domainIndex = sqlobject.DatabaseIndex({'column':domain, 'length':8}) CachedDomain.createTable(ifNotExists=True)

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[Twisted-Python] Re: [Twisted-commits] r14296 - protocol wrapper which logs everything that goes through it
by Andrew Bennetts 22 Aug '05

22 Aug '05

On Sun, Aug 21, 2005 at 08:42:33AM -0600, Jp Calderone wrote: > Author: exarkun > Date: Sun Aug 21 08:42:33 2005 > New Revision: 14296 > > Modified: > trunk/twisted/protocols/policies.py > trunk/twisted/test/test_policies.py > Log: > protocol wrapper which logs everything that goes through it > > Modified: trunk/twisted/protocols/policies.py > ============================================================================== > --- trunk/twisted/protocols/policies.py (original) > +++ trunk/twisted/protocols/policies.py Sun Aug 21 08:42:33 2005 > @@ -428,6 +428,69 @@ > timeoutPeriod=self.timeoutPeriod) > > > +class TrafficLoggingProtocol(ProtocolWrapper): [...] Hmm, this seems to be similar to twisted.manhole._inspectro.LoggingProtocol. Can they be combined? -Andrew.

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[Twisted-Python] Trial: The Volunteering
by Jonathan Lange 22 Aug '05

22 Aug '05

Hello Everyone. I've been off-list for a while, but I am back. As the original author of Trial, I still feel partly responsible for it. So, I would like to become the official maintainer of Trial again. I am _not_ planning on re-writing Trial. Rather, I'm going to restrict myself to fixing bugs, doing incremental refactorings to clean-up the cruft and rejecting ideas for new features. I've asked Jonathan Simms (slyphon) whether he would mind. He is more than happy for me to assume the mantle of Trial maintainer. Let me know if there are any objections. Otherwise, start assigning trial bugs to me by default. cheers, jml

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[Twisted-Python] Possibly of interest
by Michael Sparks 22 Aug '05

22 Aug '05

[ Please excuse me if this isn't of interest. I saw this and suspected that people here might be interested (whether agreed with or not) though - if it isn't, my apologies! ] Hi, I was forwarded a link to this paper just recently (and skimming the past 5-6 months of archives here it doesn't look like it's been posted to this list). Since it looks interesting I thought I'd forward a copy to yourselves. http://www.usenix.org/events/hotos03/tech/full_papers/vonbehren/vonbehren_h… Whilst the paper is a couple of years old, the comments are probably interesting because whilst it describes itself really as "threads are better than events" their implementation is based on C-Coroutine library (that doesn't use threads...) and suggests in its conclusions: "In the future, we advocate tight integration between the compiler and the thread system, which will result in a programming model that offers a clean and simple interface to the programmer while achieving superior performance." Which to me smacks of generators - which IMO can be viewed as just a different way of wrapping up the event stack. (Which doesn't entirely surprise me - one of their influences listed in para 3 of the introduction was Inktomi's Traffic Server - somewhere I worked before the BBC, and came to the same conclusions they did. //Wrongly or rightly//, dunno :-) (On an unrelated note: Tommi - after the discussions we had at Europython I came back and discussed general timelines for making our Kamaelia stuff work transparently with Twisted for an alpha stage. We came to the conclusion that we'd like to push that out to a 1.0.0 timeframe, which would probably be around a year from now. It gives us still the freedom in that respect to be able to answer "use twisted" when people ask us what they should use when using python for production servers :-) Also it means that /if/ we do achieve clean integration, that the answer won't change ;-) Anyway, hopefully the paper is of interest (even if disagreed with!), if it isn't, my apologies! Best Regards, -- Michael Sparks, Senior R&D Engineer, Digital Media Group Michael.Sparks(a)rd.bbc.co.uk, http://kamaelia.sourceforge.net/ British Broadcasting Corporation, Research and Development Kingswood Warren, Surrey KT20 6NP This e-mail may contain personal views which are not the views of the BBC.

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[Twisted-Python] Re: [Twisted-commits] r14281 - Cope with integer owner/group info.
by Jp Calderone 22 Aug '05

22 Aug '05

On Sun, 21 Aug 2005 00:16:32 -0600, Andrew Bennetts <spiv(a)wolfwood.twistedmatrix.com> wrote: >Author: spiv >Date: Sun Aug 21 00:16:32 2005 >New Revision: 14281 > >Modified: > trunk/twisted/protocols/ftp.py >Log: >Cope with integer owner/group info. > >Modified: trunk/twisted/protocols/ftp.py >============================================================================== >--- trunk/twisted/protocols/ftp.py (original) >+++ trunk/twisted/protocols/ftp.py Sun Aug 21 00:16:32 2005 >@@ -370,8 +370,8 @@ > 'directory': directory and 'd' or '-', > 'permissions': formatMode(permissions), > 'hardlinks': hardlinks, >- 'owner': owner[:8], >- 'group': group[:8], >+ 'owner': str(owner)[:8], >+ 'group': str(group)[:8], > 'size': size, > 'date': formatDate(time.gmtime(modified)), > 'name': name} The interface doc string explicitly states 'owner' and 'group' here will already be strings. I don't see any reason to widen the interface, but if you do, please update the documentation. Jp

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[Twisted-Python] twisted & pydispatcher?
by Henning.Ramm＠mediapro-gmbh.de 21 Aug '05

21 Aug '05

Hi ho! Would you recommend or discourage using pyDispatcher in a twisted application? Are there any known traps? Best regards, Henning Hraban Ramm Südkurier Medienhaus / MediaPro Support/Admin/Development Dept.

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[Twisted-Python] Re: [Twisted-commits] r14280 - Less fragile error checking.
by Jp Calderone 21 Aug '05

21 Aug '05

On Sun, 21 Aug 2005 00:14:57 -0600, Andrew Bennetts <spiv(a)wolfwood.twistedmatrix.com> wrote: >Author: spiv >Date: Sun Aug 21 00:14:54 2005 >New Revision: 14280 > >Modified: > trunk/twisted/protocols/ftp.py >Log: >Less fragile error checking. > >Modified: trunk/twisted/protocols/ftp.py >============================================================================== >--- trunk/twisted/protocols/ftp.py (original) >+++ trunk/twisted/protocols/ftp.py Sun Aug 21 00:14:54 2005 >@@ -598,7 +598,8 @@ > if err.check(FTPCmdError): > msg = RESPONSE[err.value.errorCode] % (err.value.errorMessage,) > self.sendLine(msg) >- elif err.check(TypeError): >+ elif (err.check(TypeError) and >+ err.value.args[0].find('takes exactly') != -1): > self.reply(SYNTAX_ERR, "%s requires an argument." % (cmd,)) > else: > log.msg("Unexpected FTP error") > If you want to make it "less fragile", please use inspect.getargspec() to determine the number of arguments it expects. Messages are likely to be changed or localized. Jp

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