Mailman 3 January 2002 - Twisted

[Twisted-Python] Throwing exceptions to the client
by Cory Dodt 25 Jan '02

25 Jan '02

Still working on my ACL problem. Use case: client connects, calls a perspective_method which is not in its ACL. In my test client, I call perspective.createUsers(['cdodt']) 1) At the server, perpsective method calls self.assertPermission("create_users") This assertion fails, so assertPermission throws PermissionDenied. When this happens, client gets a string with the traceback. This looked cool at first, until I tried to handle the error with my failure callback. In order to differentiate between PermissionDenied and, for example, UserAlreadyExists errors, I would have to parse what I get back from the server. Parsing strings to find out what happened puts us back at the protocol layer, and is something my code shouldn't have to do. MUCH nicer would be if the server tossed the real exception to the client, not a string. Referenceable, perhaps. Is it possible to make this happen when an exception gets raised? 2) Another workable solution would be for the perspective_method to return an exception instead of throwing it. radix clued me in on Referenceables, so I'm working on making my exception Referencable. That's when I noticed that the example code is missing Referenceables. Ref'ables and Copyables seem to be fairly intrinsic to pb, so they should probably show up in the examples somewhere. Thanks, C __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

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[Twisted-Python] Sample app for docs
by Itamar Shtull-Trauring 23 Jan '02

23 Jan '02

How about a finger daemon? We can have a web frontend, and use PB to set .plans, and store the .plans in PostgreSQL.

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[Twisted-Python] patchlet
by Jaakko Niemi 22 Jan '02

22 Jan '02

To get the Debian package build include protocols.ldap. Hmm, perhaps setup.py should just look what's in there. --- setup.py~ Fri Sep 14 04:22:48 2001 +++ setup.py Sun Jan 20 20:44:56 2002 @@ -59,6 +59,7 @@ "twisted.manhole.ui", "twisted.persisted", "twisted.protocols", + "twisted.protocols.ldap", "twisted.python", "twisted.reality", "twisted.reality.ui",

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[Twisted-Python] man page -g, deb stuff
by Cory Dodt 22 Jan '02

22 Jan '02

The man page for twistd in the .deb package does not contain the new -g option or any info about plugins. Also of note: + the .deb does not contain twistd-debug + the .deb does not contain any of the .tac's in examples/ Just keeping you honest:-) C __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/

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[Twisted-Python] Re: [Twisted-commits] CVS: Twisted/twisted/spread banana.py,1.13,1.14 jelly.py,1.12,1.13 pb.py,1.51,1.52
by Itamar Shtull-Trauring 21 Jan '02

21 Jan '02

Sean just added unicode to banana and jelly. 1. Will this run on 1.5.2? 2. You had better encode the data before writing it - as far as I can see from the patch you do not. I suggest UTF-8. 3. As glyph pointed out, do we even need unicode support in Banana? Keeping it in jelly (u'foo' --> ['unicode', u'foo'.encode("UTF8")] would be the transform) would work just as well, without requiring people who implement banana to deal with it.

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[Twisted-Python] FTP Client protocol for Twisted..
by Michael Bacarella 21 Jan '02

21 Jan '02

Hi, I just joined the list. For your public enjoyment I present an FTPClient protocol implementation for Twisted. The class definition: http://m.bacarella.com/playground/ftpclient.py Example code: http://m.bacarella.com/playground/exftpclient.py ftpclient.py should go into twisted/protocols to use the example. You may decide that it's better to suck it into a different file. The example simply logs into ftp.uu.net (anonymous), retrieves and prints a directory listing, and then exits. I developed it because I wanted to use Twisted for an IRC bot which needed to be able to index FTP sites, so I basically stopped once it met my needs. Sorry if it's missing some features.. Comments or suggestions are welcome. -- Michael Bacarella | 545 Eighth Ave #401 | New York, NY 10018 Systems Analysis & Support | mike(a)bacarella.com Managed Services | 212 946-1038

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[Twisted-Python] Bug reports
by Itamar Shtull-Trauring 16 Jan '02

16 Jan '02

Until we have a bug tracker, some bug reports, so we don't forget: 1. protocol.Factory's startFactory method is called twice on start up. 2. Various SQL code doesn't use SQL quoting (that means you, Sean :) 3. The new Perspective code has a bug, where if you ask an identity for a non-existent service/perspective pair, it raises a KeyError which is not caught anywhere. You can test this by switching pbechoclient.py to connect to service "foo" instead of "pbecho". This is some wierd Deferred thing, and I have no idea where to deal with it.

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[Twisted-Python] representing groups
by Cory Dodt 14 Jan '02

14 Jan '02

Since this is not really related to ACL's, I've decided to make this a separate thread on its own. I want to know how to represent groups in passport. A group would simply be a group of Identities, but who owns them? Who's responsible for making sure all Identities are in at least one group? How do you check if a particular object is owned by a group? Or are these questions not solved yet? Thanks! C __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/

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[Twisted-Python] Experiences with twisted.spread: representing an ACL
by Cory Dodt 14 Jan '02

14 Jan '02

I am working on a networked backup server which is so new it doesn't even have a project page up on SF yet, although it might by the end of the week. To build this I am using spread and passport instead of building my own protocol. I'm having trouble with some of the concepts in spread, and at this point I'm still too naive to know whether I'm missing the point of something or whether passport is actually missing something I need. I want to implement access control lists. For each Identity, I want to assign a simple list of strings which more or less represent the ability to access a Perspective. For example: useracl=[ "store_files", "read_files", "encrypt", "create_lbu" ] There is a StoreFilesService, a ReadFilesService, and a CreateLBUService, and a Perspective for each. The "encrypt" permission is a modifier to Store and Read files, so I'm not sure how to implement that yet but I'll cross that bridge when I come to it. I have subclassed the Authorizer thus: class Authorizer(passport.Authorizer): def addIdentity(self, identity): if self.identities.has_key(identity.name): raise passport.KeyError("Already have an identity by that name.") self.identities[identity.name] = identity if identity.permissions == None: raise MissingPermissionsException(identity) # create all perspectives the user should have for permission in identity.acl: svc=servicelist.services[permission](permission, tap.the_app) svc.createPerspective(identity.name).setIdentity(identity) identity.addKeyForPerspective(svc.getPerspectiveNamed(identity.name)) Does passport already has something like the ACL mechanism which allows you to easily bind an ACL to a user? Is my solution the most parsimonious or do I really have to subclass the Authorizer to achieve this? It seems like I should be able to throw in a callback somewhere that creates the eligible service/perspective pairs when a user is added to the system. Second, if I modify a user's ACL, for example to grant a permission, where's the callback to create a new s/p pair for that permission? I have a suspicion that this is already taken care of somewhere in passport and I'm just missing the point. That's all for now, thanks. C __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/

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[Twisted-Python] Changelog
by Itamar Shtull-Trauring 14 Jan '02

14 Jan '02

we now have a changelog, a log of changes. use the changelog. the changelog is to be used. enter new stuff in the changelog.

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