Mailman 3 April 2003 - Twisted

[Twisted-Python] spawnProcess and environment inheritance
by Brian Warner 29 Apr '03

29 Apr '03

I wanted to ask what people thought about a potential change to the way reactor.spawnProcess() sets up the child's environment variables. The current default is to provide an empty environment to the child: reactor.spawnProcess() has a env={} default parameter. I'm wondering if this should be changed to env=None, which would instruct os.execvpe() to let the child inherit the environment from the parent process. This showed up in a recent test_process.py failure, which effectively compared a "file not found" error message obtained with popen3() against a similar one retrieved with reactor.spawnProcess(). The test failed when it was run in a localized environment. popen3() inherited $LANG from the parent (in this case, LANG was set to French), and the error message came out in one language, whereas spawnProcess() cleared the environment, and the error came out in English. The two didn't match, so the test harness thought spawnProcess had somehow failed. I've changed test_process.py to explicitly pass env=None to all child processes, but given that Python's popen2 and os.exec library functions all default to inheritance rather than an empty environment, I'm thinking it might be a good idea to match them and have spawnProcess() default to inheritance too. pros: Less surprise factor for those used to normal unix behavior. Would reduce the differences between programs run from the shell and those run from inside spawnProcess. cons: Sometimes you want to clean the environment as a security measure. The existing behavior has been around for a while and changing it might cause problems. What do you all think? The change in question, in case you'd like to try it out, would be the following one-liner: Index: twisted/internet/default.py =================================================================== RCS file: /cvs/Twisted/twisted/internet/default.py,v retrieving revision 1.72 diff -u -r1.72 default.py --- twisted/internet/default.py 21 Apr 2003 15:32:15 -0000 1.72 +++ twisted/internet/default.py 29 Apr 2003 21:19:32 -0000 @@ -149,7 +149,7 @@ # IReactorProcess - def spawnProcess(self, processProtocol, executable, args=(), env={}, path=None, + def spawnProcess(self, processProtocol, executable, args=(), env=None, path=None, uid=None, gid=None, usePTY = 0): p = platform.getType() if p == 'posix': thanks, -Brian

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[Twisted-Python] Twisted 1.0.4 - Possible typo in twisted.web.vhost ?
by pinard＠iro.umontreal.ca 29 Apr '03

29 Apr '03

For Twisted 1.0.4, file twisted/web/vhost.py, line 100 is: ----------------------------------------------------------------------> return self.hosts.get(host, self.default or error.NoResource("host %s not in vhost map" % repr(host))) ----------------------------------------------------------------------< Could it be (?) that this line should be written: ----------------------------------------------------------------------> return self.hosts.get(host, self.default) or error.NoResource("host %s not in vhost map" % repr(host)) ----------------------------------------------------------------------< or, to keep it under 80 columns: ----------------------------------------------------------------------> return (self.hosts.get(host, self.default) or error.NoResource("host %s not in vhost map" % repr(host))) ----------------------------------------------------------------------< If we can rely on Python 2.2, we could simplify it a bit more: ----------------------------------------------------------------------> return (self.hosts.get(host, self.default) or error.NoResource("host %r not in vhost map" % host)) ----------------------------------------------------------------------< -- François Pinard http://www.iro.umontreal.ca/~pinard

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[Twisted-Python] Reloading of the same `.rpy' file
by pinard＠iro.umontreal.ca 29 Apr '03

29 Apr '03

Hi, Twisted people. Playing with resource files, I noticed that the outer-level code within `.rpy' files is executed again every time the page using them is fetched by the browser. If `test.py' contains: ----------------------------------------------------------------------> print "Hello!" ... resource = ... ----------------------------------------------------------------------< than each `Alt-R' within Netscape, once `http://localhost:8080/test.rpy' has been loaded, will have "Hello!" added to the Twisted log file. I would have expected the resource file to be loaded once, and reused after without being wholly re-initialised each time. I tried "import remanent" within the resource file, and checked that "remanent" is loaded and intialised only once (moreover, it gets compiled!), so I'm tempted to move all code from `test.rpy' into `remanent.py' and reduce `test.rpy' to a mere: ----------------------------------------------------------------------> import remanent resource = remanent.resource ----------------------------------------------------------------------< which is a bit ridiculous if it has to be a standard idiom. On the other hand, for debugging, I agree it is a bit handsome being able to modify `test.rpy' and trying the new version without restarting the server. This is a weak justification however. Whenever the `.tap' file needs to be rebuilt, the server needs to be restarted anyway. This soon warrants a Makefile, and adding another dependency over `test.rpy' is a simple matter. Maybe the Twisted design is trying, here, to spare memory by not keeping `.rpy' code in its memory, in case these would be very numerous or contain a lot of code? Or trying to protect itself against leaks from such, but how? I have the vague feeling that I'm missing something important in this area. Would some soul be kind enough to accept enlightening mine? :-) -- François Pinard http://www.iro.umontreal.ca/~pinard

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[Twisted-Python] Newbie reading Twisted book!
by Francois Pinard 29 Apr '03

29 Apr '03

Hi, people. I just want to share my enthusiasm, so far, at reading the Twisted book (from the `doc/howto/' directory). Whoever wrote it uses a vivid and interesting style of prose which triggers pleasure. Thanks for this. -- François Pinard http://www.iro.umontreal.ca/~pinard

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[Twisted-Python] Tagging
by Moshe Zadka 29 Apr '03

29 Apr '03

FYI: last-python2_1-compatible is a tag that marks the last place where Twisted is (in theory) Python 2.1 compatible -- Moshe Zadka -- http://moshez.org/ Buffy: I don't like you hanging out with someone that... short. Riley: Yeah, a lot of young people nowadays are experimenting with shortness. Agile Programming Language -- http://www.python.org/

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[Twisted-Python] Re: [Twisted-commits] "no such user" is too informative, no need to give attackers more information than necessary
by Bruce Mitchener 28 Apr '03

28 Apr '03

itamarst CVS wrote: > Modified files: > Twisted/twisted/web/distrib.py 1.47 1.48 > > Log message: > "no such user" is too informative, no need to give attackers more information than necessary While there is good motivation for not making this public info, it seems like it would be a good thing to make this available to someone debugging the system, either by way of the log file or some other means. While not necessarily appropriate for Twisted, one approach that I've used well in the past (in my own webserver and web app software) was to have an error page that recognized authenticated users and would display generic errors to unknown or unauthorized users, and informative/descriptive errors to authorized people (as well as direct access to the web-based tools used to determine what went wrong and so on). Maybe some sort of policy framework might let that happen within Twisted or some other generalized logging infrastructure. But at the least, it seems like this sort of info should be logged. Cheers, - Bruce > ViewCVS links: > http://twistedmatrix.com/users/jh.twistd/viewcvs/cgi/viewcvs.cgi/twisted/we… > > Index: Twisted/twisted/web/distrib.py > diff -u Twisted/twisted/web/distrib.py:1.47 Twisted/twisted/web/distrib.py:1.48 > --- Twisted/twisted/web/distrib.py:1.47 Tue Dec 3 03:21:48 2002 > +++ Twisted/twisted/web/distrib.py Mon Apr 28 13:36:52 2003 > @@ -230,10 +230,7 @@ > pw_name, pw_passwd, pw_uid, pw_gid, pw_gecos, pw_dir, pw_shell \ > = pwd.getpwnam(username) > except KeyError: > - return error.ErrorPage(http.NOT_FOUND, > - "No Such User", > - "The user %s was not found on this system." % > - repr(username)) > + return error.NoResource() > if sub: > twistdsock = os.path.join(pw_dir, self.userSocketName) > rs = ResourceSubscription('unix',twistdsock)

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[Twisted-Python] mktap problem, cPickle.UnpickleableError
by Allan Streib 28 Apr '03

28 Apr '03

Hi, I am trying to create an XMLRPC server based on the plugins example in the HOWTO documentation. My TAP construction module looks like: from twisted.web import server from MyXMLRPCServer import methods from twisted.python import usage class Options(usage.Options): optParameters = [["port", "p", 8080, "Port number for XMLRPC Server."], ["ldapurl", None, "ldap://localhost/", "URL for ldap directory server."], ["ldapbinddn", None, "cn=Manager,dc=iu,dc=edu", "Bind DN for directory"], ["ldappw", None, None, "Password for directory Bind DN"]] def postOptions(self): if self['ldappw'] is None: raise usage.UsageError, "Must provide option ldappw" def updateApplication(app, config): port = int(config['port']) factory = server.Site(methods.MyXMLRPCMethods(config)) app.listenTCP(port, factory) When I run mktap with the appropriate parameters for my application, I get: Traceback (most recent call last): File "/usr/local/bin/mktap", line 30, in ? run() File "/usr/local/lib/python2.2/site-packages/twisted/scripts/mktap.py", line 252, in run a.save() File "/usr/local/lib/python2.2/site-packages/twisted/internet/app.py", line 754, in save dumpFunc(self, f) File "/usr/local/lib/python2.2/site-packages/twisted/internet/app.py", line 736, in dumpFunc _dump(obj, file, 1) cPickle.UnpickleableError: Cannot pickle <type 'LDAP'> objects I think I am getting this because my "MyXMLRPCMethods" instance contains a connection to the LDAP Server. So what is the best approach to work around this. Sorry if this is a newbie question; I am a newbie. Allan

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[Twisted-Python] Serving up php apps: gallery
by Stephen Boulet 28 Apr '03

28 Apr '03

Anyone familiar with the php app "The Gallery" for online photo galleries? Is this the type of thing twisted can serve up? I understand it makes use of the apache module "mod_rewrite"... Thanks. -- Stephen From here to there and there to here, funny things are everywhere. -- Dr Seuss

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[Twisted-Python] Twisted 1.0.4 - Tildes in the book
by Francois Pinard 28 Apr '03

28 Apr '03

Hi, still me... In the Twisted 1.0.4 book -- I hope this reference is unambiguous enough, I have not seen more than one :-) -- there is a problem here and there with `~' being shown over the next character (`/' for example) instead of prior to it as intented. At many places, tildes are OK, however. Should I try reporting all problematic cases? I guess not, as the problem is likely to be the same at all places, and some global action could be taken. The example I'm currently looking at is at the end of page 136 (6. Web Applications; 6.1.2 Before we begin) on this quote: Make sure the `TwistedQuotes' directory is on your PYTYONPATH, put `webquotes.rpy' and `WebQuotes.html' in your `~/public_html' directory, and you are ready to go. The `~' and `/' on the last sentence are at the same character position. -- François Pinard http://www.iro.umontreal.ca/~pinard

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[Twisted-Python] speed on intranet?
by xlp223 28 Apr '03

28 Apr '03

my office has some computers with intranet. i installed twisted 1.0.4 on a computer when i visited the computer with twisted 1.0.4 from another computer,speed in intranet is slow. but since i enter into the internet on a computer through gateway, speed of visiting the computer with web server of twisted 1.0.4 in intranet is quick. why? ______________________________________ ===================================================================

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