Mailman 3 January 2005 - Twisted-web

VHostMonsterResource for url-context instead of subdomain
by Steven Armstrong 19 Jan '05

19 Jan '05

Hello twisted hackers I've been playing arround with nevow and twisted for a while now. While looking for a way to use twisted with apache I came across the following problem and hacked together a possible solution. In the twisted docs (http://twisted.sourceforge.net/TwistedDocs-1.3.0/howto/using-twistedweb.htm…) it sais to use VHostMonsterResource and proxy the documentroot to twisted. In my setup I can't do this. What I need is a way to proxy only a specific url-context to twisted while the rest of the domain remains under apache's control. This is what I came up with. It seems to work well, the nevow examples are all working with this setup. All except those that don't work in native twisted/nevow eather that is. Code is attached as vhostlocation.txt to prevent linebreaks from beeing hosed. Do you guys see any problems with this approach? Are there any implications through changing request.uri and request.prepath that I didn't think/know of? cheers Steven from twisted.python import log from nevow import vhost import re _debug = False _vhost_location_delim = "@" _vhost_re = re.compile('(.*)(/'+ _vhost_location_delim +'.*'+ _vhost_location_delim +'/)(.*)') class VHostLocation(vhost.VHostMonsterResource): """ Represents a single url-context of a Apache VirtualHost. Using this you do not need to proxy an entire virtual host to twisted. Instead you can proxy a specific location like: <VirtualHost *> ... ServerName www.example.com RewriteRule ^/nevow-app$ /nevow-app/ [R=301,L] ProxyPass /nevow-app/ http://localhost:8080/vhost/http/www.example.com:80/@nevow-app@/ # this also works #ProxyPass /nevow/app/ http://localhost:8080/vhost/http/www.example.com:80/@nevow/app@/ ... </VirtualHost> In this example only the http://www.example.com/nevow-app location is handled by twisted. The rest of the VirtualHost remains under Apache's control. The location used by Apache is passed to twisted through the trailing @location-name@. This is then used to fix request.uri and the request.postpath list to hold the segments needed to create a valid absolute url. So the ProxyPass directive in the above example is seen/used as: Apache internal: /nevow-app/somepage Twisted internal: /somepage Twisted absolute: http://www.example.com/nevow-app/somepage """ def _fix_segments(self, segments): """ Removes the vhost_location from the given segments if necessary. Returns the modified segments and the vhost_location. vhost_location would be "nevow-app" in the example mentioned above. segments before: ('http', 'www.example.com:80', '@nevow-app@', 'somepage') segments after: ('http', 'www.example.com:80', 'somepage') """ segments_string = "/".join(segments) vhost_location = _vhost_re.sub(r'\2',segments_string) # remove leading and trailing slash and delimiter vhost_location = vhost_location[(len(_vhost_location_delim)+1):-(len(_vhost_location_delim)+1)] new_segments = tuple(_vhost_re.sub(r'\1/\3',segments_string).split("/")) return new_segments, vhost_location def _fix_path(self, request, vhost_location): """ Fixes the requests uri. Fixes the requests postpath list. Given the above example: request.uri before: /@nevow-app@/somepage request.uri after: /somepage request.postpath before: ['http', 'www.example.com:80', '@nevow-app@', 'somepage'] request.postpath after: ['http', 'www.example.com:80', 'nevow-app', 'somepage'] """ request.uri = request.uri.replace("/"+ _vhost_location_delim + vhost_location + _vhost_location_delim, "") #request.path = "/"+ vhost_location + request.path postpath = "/".join(request.postpath) postpath = postpath.replace(_vhost_location_delim + vhost_location + _vhost_location_delim, vhost_location) request.postpath = postpath.split("/") def locateChild(self, ctx, segments): """ First fixes the given segments. see _fix_segments Then passes the method call to the superclass. Then fixes the request.postpath. see _fix_path returns what the superclass returned without changing it. """ request = inevow.IRequest(ctx) if _debug: log.msg("request.uri: %s" % request.uri) log.msg("request.path: %s" % request.path) log.msg("request.prepath: %s" % request.prepath) log.msg("request.postpath: %s" % request.postpath) log.msg("segments: %s" % str(segments)) segments, vhost_location = self._fix_segments(segments) if _debug: log.msg("segments after: %s" % str(segments)) log.msg("vhost_location: %s" % vhost_location) res, segs = vhost.VHostMonsterResource.locateChild(self, ctx, segments) if _debug: log.msg("segs: %s" % str(segs)) if vhost_location: self._fix_path(request, vhost_location) if _debug: log.msg("request.uri after: %s" % request.uri) log.msg("request.postpath after: %s" % request.postpath) return res, segs application = service.Application("examples-vhost") page = Examples() #vResource = vhost.VHostMonsterResource() vResource = VHostLocation() page.putChild('vhost', vResource)

1 0

Sample code to run twisted web server
by Mosas 18 Jan '05

18 Jan '05

Dear All, Can anyone send some sample scripts to run in the twisted webserver. EspeciallY I am in need of sample rpy scripts. ________________________________________________________________________ Yahoo! India Matrimony: Find your life partner online Go to: http://yahoo.shaadi.com/india-matrimony

3 2

/freeform_post!!random causes exceptions
by Andrea Arcangeli 18 Jan '05

18 Jan '05

This fixes a server exception that you can trigger by using an url like the one in subject on a page that misses the binding. This fixed the problem for my application, it's probably the right fix too. I noticed it after logging out of the session and pressing some back on the web browser, the forms that were valid inside the account, weren't valid in the guest area and caused exceptions. BTW, I wrote an exception handler that sends me any exception by email and redirects the user to a nice message (so you can debug any problem before people complains and you don't show the sensitive data to the user) if the client IP is != localhost (so you can still debug it great with the formatter in localhost). If anybody wants to see the code or to merge it into nevow feel free to ask (though it depends on twisted for delivering the email). Index: nevow/rend.py =================================================================== --- nevow/rend.py (revision 1057) +++ nevow/rend.py (working copy) @@ -127,7 +127,8 @@ ctx.remember(request, inevow.IRequest) cf = iformless.IConfigurableFactory(self) c = cf.locateConfigurable(ctx, configurableName) - return self.webFormPost(request, self, c, ctx, bindingName, request.args) + if c: + return self.webFormPost(request, self, c, ctx, bindingName, request.args) return NotFound

6 12

/__logout__ doesn't expire the session
by Andrea Arcangeli 15 Jan '05

15 Jan '05

Because of subject, any data structure linked to the user is still visible to the webserver if the user explicitly types /__logout__ in the URL. That doesn't seem very safe behaviour. The userdb/ in the example directory does this to workaround it: def logout(self, request): request.getSession().expire() request.setComponent(iformless.IRedirectAfterPost, "/"+guard.LOGOUT_AVATAR) but that workaround is insecure, since the user can type __logout__ by himself (if he knows the nevow code at least) and logout without clearing the session. This problem would have caused a (very minor) security issue to me, but it might have more serious implications in other apps. So I'd suggest to expire the session automatically in the __logout__ avatar so that a new fresh (anonymous) session will have to be allocated after logout. The last fix I posted isn't applied yet, so I append it again. My debug code now runs as I expected (i.e. the session is regenerated after logout and I don't need to expire it by hand anymore insecurely like userdb does). Please apply thanks! Index: nevow/rend.py =================================================================== --- nevow/rend.py (revision 1069) +++ nevow/rend.py (working copy) @@ -127,7 +127,8 @@ ctx.remember(request, inevow.IRequest) cf = iformless.IConfigurableFactory(self) c = cf.locateConfigurable(ctx, configurableName) - return self.webFormPost(request, self, c, ctx, bindingName, request.args) + if c: + return self.webFormPost(request, self, c, ctx, bindingName, request.args) return NotFound Index: nevow/guard.py =================================================================== --- nevow/guard.py (revision 1069) +++ nevow/guard.py (working copy) @@ -348,7 +348,7 @@ if segments and segments[0] == LOGIN_AVATAR: return self.login(request, s, self.getCredentials(request), segments[1:]) elif segments and segments[0] == LOGOUT_AVATAR: - s.portalLogout(self.portal) + s.expire() return urlToChild(request, *segments[1:]), () else: r = s.resourceForPortal(self.portal)

5 15

SessionWrapper componentized
by Andrea Arcangeli 15 Jan '05

15 Jan '05

I'd need the SessionWrapper componentized so I can use compy to store global data for the whole site under the sessionwrapper. Or is there a better way to do it? Thanks. Index: nevow/guard.py =================================================================== --- nevow/guard.py (revision 1084) +++ nevow/guard.py (working copy) @@ -175,7 +175,7 @@ request.finish() return '' -class SessionWrapper: +class SessionWrapper(components.Componentized): __implements__ = inevow.IResource @@ -198,6 +198,7 @@ secureCookies = True def __init__(self, portal, cookieKey=None, mindFactory=None, credInterface=None, useCookies=None): + components.Componentized.__init__(self) self.portal = portal if cookieKey is None: cookieKey = "woven_session_" + _sessionCookie()

2 2

Rendering after posts
by Michael Wilson 14 Jan '05

14 Jan '05

In all the examples I've seen, the "way" to render a page after a post appears to be to set a redirect: request.setComponent(iformless.IRedirectAfterPost, "/") (from examples/userdb.tac) If I want to include some additional variables in the redirected page, it seems like that's implemented by passing parameters on the redirect in the URL. Is there another way to render another page after a post, WITHOUT using redirect? (I've tried setting docfactory again, or returning another instance of rend.Page, but those don't seem to work. Thanks!

2 1

defaultLabel formless
by Andrea Arcangeli 13 Jan '05

13 Jan '05

I noticed a minor regression in svn (defaultLabel got lost because it was set to the action string fallback), here the fix (optimizes the new code a little bit too). Index: formless/annotate.py =================================================================== --- formless/annotate.py (revision 1070) +++ formless/annotate.py (working copy) @@ -732,10 +732,9 @@ if description is None: description = adapted.description - defaultLabel, defaultDescription = labelAndDescriptionFromNameAndDocstring(key, value.__doc__) - if label is None: + if value.__doc__ is not None: + defaultLabel, defaultDescription = labelAndDescriptionFromNameAndDocstring(key, value.__doc__) label = defaultLabel - if description is None: description = defaultDescription theMethod = Method(

2 2

[announce] tamtam2 0.09 released
by Aleksandar Erkalovic 13 Jan '05

13 Jan '05

Hi, i am happy to say that i managed web site and download for my new project. tamtam2 is a mixture of wiki and publishing system. plese visit. try it, help with ideas and coding and etc... for official release i promise to make better announcement :) http://tamtam.mi2.hr:8888/NoviTam/ aco -- http://aco.mi2.hr/

1 0

Nevow and Authentication
by Daniel Henninger 10 Jan '05

10 Jan '05

Hi folk! I'm having issues wrapping my mind around the best way to handle this, so I'm hoping maybe you all have a quick answer for me. So, I am using nevow to build a web admin interface for a python-based jabber transport. I prepare the site as follows: site = appserver.NevowSite(webadmin.WebAdmin(pytrans=app.transportSvc)) reactor.listenTCP(int(config.webport), site) The WebAdmin root node is: class WebAdmin(rend.Page): and goes from there based loosely around some of the examples. Now, the problem is, I need to add authentication to the mix, and the examples show use of a portal, but I can not put two and two together to figure out how to have both authentication and the rend-based template engine. Is there something simple that I am missing here? All I need is a simple basic auth requirement to get to the WebAdmin piece. Thanks much! Daniel -- "The most addictive drug in the world is music." - The Lost Boyz

1 0

minor compile/typo fix
by Andrea Arcangeli 07 Jan '05

07 Jan '05

This fixed a compilation problem for me. I didn't actually check the correctness of the code, so this needs checking. Index: twisted/web2/requtil.py =================================================================== --- twisted/web2/requtil.py (revision 12831) +++ twisted/web2/requtil.py (working copy) @@ -59,8 +59,8 @@ return request.site.getSession(sessionCookie) except KeyError: pass - session = Session(request.site, request.site.mkuid() - site.setSession(session) + session = Session(request.site, request.site.mkuid()) + request.site.setSession(session) request.addCookie(cookiename, session.uid, path='/') request.setComponent(ISession, session) # is this needed? return session

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