Mailman 3 May 2009 - Twisted

[Twisted-Python] First time install of Twisted fails
by Uncle Roastie May 20, 2009

May 20, 2009

I'm trying to do an install of Twisted for Python 2.5.4 on Windows XP. I installed PyCrypto, OpenSSL for Windows, and PyOpenSLL. When I enter the Python interpreter and say >>> import OpenSLL I get the following error: "The procedure entry point SSL_CTX_set_info_callback could not be located in the dynamic link library ssleay32.dll." The DLL lives inside the OpenSLL bin directory, which is also on the search PATH. Any ideas? Uncle Roastie roastie(a)rochester.rr.com

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[Twisted-Python] XML-RPC for paralell clients
by Pet May 19, 2009

May 19, 2009

Hi, after playing with reactor, factory and protocol, I'm trying to implement XML-RPC server, but it seems that it is not able to handle several clients in parallel. If I call the slow function with first client and then with second client a fast function, second client will receiver the results after slow function returned. There is no factory for clients in server.Site() like in Protokoll? What is the way to do that for XML-RPC? Thanks for your help! Pet from twisted.web import xmlrpc, server from twisted.application import internet from time import sleep PORT = 11111 class ExampleXMLRPCProtokoll(xmlrpc.XMLRPC): """An example object to be published.""" def xmlrpc_echo(self, x): """ Return all passed args. """ return x def xmlrpc_add(self, a, b): """ Return sum of arguments. """ return a + b def xmlrpc_addslow(self, a, b): """ Return sum of arguments. takes time """ sleep(20) return a + b def xmlrpc_fault(self): """ Raise a Fault indicating that the procedure should not be used. """ raise xmlrpc.Fault(123, "The fault procedure is faulty.") class ExampleXMLRPCService(internet.TCPServer): def __init__(self): print "Starting XML-RPC Service..." r = ExampleXMLRPCProtokoll() internet.TCPServer.__init__(self,PORT,server.Site(r)) def main(): from twisted.internet import reactor r = ExampleXMLRPCProtokoll() reactor.listenTCP(PORT, server.Site(r)) reactor.run() if __name__ == '__main__': main()

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[Twisted-Python] Epsilon installation?
by Jasper May 19, 2009

May 19, 2009

I'm interested in taking a look at divmod Vertex, which requires divmod Epsilon, which I downloaded from here: http://divmod.org/trac/wiki/DivmodEpsilon However, when I try to 'setup.py install' Epsilon, I get the following error: Traceback (most recent call last): File "C:\Documents and Settings\Jasper\Desktop\Epsilon-0.5.12\setup.py", line 6, in ? version=version.short(), File "C:\Python24\lib\site-packages\twisted\python\versions.py", line 37, in short svnver = self._getSVNVersion() File "C:\Python24\lib\site-packages\twisted\python\versions.py", line 90, in _getSVNVersion doc = parse(file(ent)).documentElement File "C:\Python24\lib\xml\dom\minidom.py", line 1915, in parse return expatbuilder.parse(file) File "C:\Python24\lib\xml\dom\expatbuilder.py", line 928, in parse result = builder.parseFile(file) File "C:\Python24\lib\xml\dom\expatbuilder.py", line 207, in parseFile parser.Parse(buffer, 0) xml.parsers.expat.ExpatError: syntax error: line 1, column 0 This appears to be happening while parsing .../Epsilon-0.5.12/epsilon/.svn/entries, which isn't xml at all... Inspecting version.py, I found I could avoid the issue by deleting the .svn dir. Is this just a matter of the .svn dirs being accidentally included in the Epsilon release? Or, put another way, am I masking some sort of meaningful version check by doing this? -Jasper PS And what's up with the dom parsing of non-xml anyway?

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[Twisted-Python] File persistence without blocking the main event loop?
by Arun Thampi May 18, 2009

May 18, 2009

Hi guys - I'm just beginning to learn about Twisted and was wondering if there is a way to use the built-in Twisted persistence libraries such as dirdbm etc. without blocking the main event loop? I read about an approach which uses deferToThread (comment#3 here: http://code.activestate.com/recipes/413609/) but if you are persisting quite often, doesn't the creation of threads on every persist-call make it very expensive? Any pointers will be much appreciated. Thanks guys! Cheers, Arun -- It's better to be a pirate than join the Navy - Steve Jobs http://arunthampi.wordpress.com

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[Twisted-Python] help using deferred
by Luigi Conte May 18, 2009

May 18, 2009

Hi people, I'm luigi and I'm a student at Politecnico di Milano, Italy. I'm working for a graduate thesis on a framework called usher. It provides an API to do connect e command operations. It manages all those calls with a defferred object (i think). In fact when I call the connect it returns me a defferred object. All that i want to know is how to call the other operations with this object and how to know when an operation is completely done. The procedure I call is simple: connect method, start method many times, stop method, disconnect method. I want to call these methods sequentially because I have to fallow a list of commands so I have to be sure the previous methods are already been invoked. I'll post the main methods hoping someone could help me in how to add the method in the deferred and how to know when it is completely invoked. # Connect def connect(self, ctrl_host, ctrl_port, user, passwd): """Connect to an Usher control server. @param ctrl_host: fqdn where Usher controller is running @type ctrl_host: string @param ctrl_port: port number Usher controller is listening on @type ctrl_port: int @param user: username of user connecting to Usher controller @type user: string @param passwd: password of user connecting to Usher controller @type passwd: string return: Deferred which returns and L{UsherResult} rtype: twisted.internet.defer.Deferred """ # serialize access to connect if not self.connect_lock.acquire(False): raise UsherEx, "Connection Pending" if self.factory: self.disconnect() # reset vms self.vms = {} # reset passwd to None until we're connected self.passwd = None self.factory = APIFactory() self.factory.api = self # connect to server reactor.connectSSL(ctrl_host, ctrl_port, self.factory, ssl.ClientContextFactory()) d = self.factory.login(credentials.UsernamePassword(user, passwd), client=self) d.addErrback(self._handle_err, misc.whoami()) d.addCallback(self._connected_to_ctrl, ctrl_host, ctrl_port, user, passwd) return d # start def start(self, cluster=None, prefix='', vmlist=None, count=None, first=None, last=None, dregex=None, dlist=None, dryrun=False, eid=None, **kw): """Start a VM or set of VMs @param cluster: Name of cluster to which VMs should belong @type cluster: string @param prefix: prefix to prepend to VM names @type prefix: string @param vmlist: list of strings of VMs to start @type vmlist: list of strings @param count: Number of consecutive VMs to start @type count: int @param first: Lowest number of VM to start @type first: int @param last: Highest number of VM to start @type last: int @param dregex: regular expression to match against destination LNM names @type dregex: list of strings @param dlist: list of strings to match against destination LNM names @type dlist: list of strings @param dryrun: Show what would have happened if the command had been run without the dryrun command (at the instant that the dryrun command was run of course) @type dryrun: bool @param eid: mechanism for admin user to be able to specify an alternate username for forming suffix for regex @type eid: string @param kw: Extra arguments passed to controller for use by plugins or LNM. Any keywords starting with 'vm_' are added to VM's uargs parameter. Note, the controller actually checks for two kw arguments: ram and ip_addrs. Though these are, strictly speaking, VM parameters, they're considered important enough that the controller checks for them. @type kw: dict @return: Deferred which returns an L{UsherResult} @rtype: twisted.internet.defer.Deferred @raise UsherNotConnected: Raised when not connected to Usher Controller @raise UsherPBDeadRefEx: Raised when capability for Usher Controller goes stale. Must reconnect when this happens @raise UsherInvalidInputEx: Raised when an invalid input or combination of parameters is received. @attention: The following conditions must hold: 1. first, last, and count must be non-negative 2. specifying first requires last or count 3. cannot use count with vmlist 4. cannot use count with both first and last """ # make sure we're connected if not self.aref: raise UsherNotConnectedEx # combine these to reduce params if ((first and first < 0) or (last and last < 0) or (count and count < 0)): raise UsherInvalidInputEx( "first, last, and count must be non-negative") vmrange = (first,last,count) # arg check self._arg_check(vmlist, vmrange) # get final destination list dlist = self._namecomplete(dlist, suffix=self.suffix) self._check_lnmlist(dlist) dregex = self._regex_append(dregex, dlist) dlist = self._regex_filter(dregex, self.lnms.keys()) # complete names (if necessary) in the vmlist vmlist = self._namecomplete(vmlist, cluster, eid) # check that the vms specified don't already exist self._check_vmlist(vmlist, isin=True) vmlist = self._get_vm_names_to_start(vmlist, cluster, prefix, vmrange, eid) # controller handles eid from kw, so add it if eid: kw['eid'] = eid if dryrun: d = UsherResult('dryrun', msg = 'started:' + linesep + linesep.join(vmlist)) return d try: if vmlist: d = self.aref.callRemote("start", vmlist, dlist, **kw) d.addErrback(self._handle_err, misc.whoami()) else: raise UsherInvalidInputEx( "No VMs started. No unique VMs specified in command") return d except pb.DeadReferenceError, ex: raise UsherPBDeadRefEx If you want, all the package is at http://usher.ucsd.edu/downloads/snapshots/usher/latest/usher-latest.tgz in the client folder you'll find the api.py Thank you very much hoping someone will help this totally inexpert user, Luigi.

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com May 17, 2009

May 17, 2009

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[Twisted-Python] How to make a service dependent of another?
by coder_gus May 15, 2009

May 15, 2009

Hi, I have a pb client and a tcp server. How can I make the server start only after/if the client started? Thanks.

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Re: [Twisted-Python] How to make a service dependent of another?
by Terry Jones May 15, 2009

May 15, 2009

>>>>> "Gus" == coder gus <coder_gus(a)lavabit.com> writes: Gus> I have a pb client and a tcp server. How can I make the server start Gus> only after/if the client started? Hi Gus You might take a look at the code here http://www.twistedmatrix.com/pipermail/twisted-python/2009-February/019249.… and if you go back a couple of mails in that thread you'll see some more discussion. BTW, this approach hasn't received much comment, so you shouldn't assume it's bulletproof or even recommended. But I use it many times every day to launch about half a dozen twistd multiservices, and have never had a problem. You use it like a regular multiservice, but you can pass it a service which is treated slightly specially. The other services you add will not be started unless the service you pass to __init__ starts properly (you can know this by having its startService return a deferred). Make sense? Terry

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Re: [Twisted-Python] SPAM-LOW: Re: Conch Checkers Help
by asset May 15, 2009

May 15, 2009

I tried that checker, but it failed authentication. Im not sure if theres a way to tell it which users can authenticate or if it just succeeds with any valid user, but it would'nt go through. I'm also not sure if it was intended for linux distros like Ubuntu (which is what im testing on). I even tried running my application via sudo in case the OS was blocking auth tests from a non priviledged user. I think ill do some manual tests with the pwd module it uses in order to drill out why its not working. Thx for your help Paul. TWKiel ---------------------------------------- From: "Paul Swartz" <paulswartz(a)gmail.com> Sent: Thursday, May 14, 2009 12:11 PM To: asset(a)impactdamage.com, "Twisted general discussion" <twisted-python(a)twistedmatrix.com> Subject: SPAM-LOW: Re: [Twisted-Python] Conch Checkers Help On 05/14/2009 07:14 PM, asset wrote: > Can somebody point me into the right direction in how to switch out > checkers.InMemoryUsernamePasswordDatabaseDontUse with something that > would authenticate linux users, like root? You're probably looking for twisted.conch.checkers.UnixPasswordDatabase. -p -- Paul Swartz paulswartz at gmail dot com http://paulswartz.net/ AIM: z3penguin

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[Twisted-Python] Conch Checkers Help
by asset May 15, 2009

May 15, 2009

Can somebody point me into the right direction in how to switch out checkers.InMemoryUsernamePasswordDatabaseDontUse with something that would authenticate linux users, like root? On some things i just cant seem to get past documentation and api docs. Hoping for a slight push in the right direction. Also doesnt help that im new to linux. Any help would be greatly appreciated. BTW, Im going to be working on a multiline version of conch.recvline to handle edit chars when transitioning screen rows, etc. Went through the pain of doing it with another raw terminal library and now id rather implement what i did with that in conch. Hopefully i wont be reinventing a wheel i havent spotted. TWKiel

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