Webpy is a tiny web framework. I use it a lot for my web-services applications.
In general, I let my web server (lighttpd) to handle virtual hosting. But as you may know, I am working on a CDN solution on top of Google App Engine, named CirruxCache. In that case, while I have absolutely no control on the server configuration, I need to handle virtual hosting from the code.
Webpy maps urls by iterating through a tuple. So my solution is quite simple: wrapping the tuple to override the __iter__ function according to an environment variable (HTTP_HOST).
Let's take this basic webpy example, without vhosting:
import web
urls = ('/(.*)', 'hello')
class hello(object):
def GET(self, name):
if not name:
name = 'World'
return 'Hello, %s' % name
if __name__ == "__main__":
app = web.application(urls, globals())
app.run()
Let's add the VhostMapper class:
import web
urls = {
'default' : ('/(.*)', 'hello'),
'my-vhost.domain.tld' : ('/(.*)', 'helloVhost')
}
class hello(object):
def GET(self, name):
if not name:
name = 'World'
return 'Hello, %s !' % name
class helloVhost(object):
def GET(self, name):
return 'Hello %s' % web.ctx.environ['HTTP_HOST']
class VhostMapper(object):
def __iter__(self):
url = urls['default']
if 'HTTP_HOST' in web.ctx.environ:
vhost = web.ctx.environ['HTTP_HOST']
if vhost in urls:
url = urls[vhost]
return iter(url)
if __name__ == "__main__":
app = web.application(VhostMapper(), globals())
app.run()
Finally, you can use curl or wget to test your vhosts:
$> curl -H "Host: my-vhost.domain.tld" http://localhost:8080/
It is not so early to announce that the next version of CirruxCache will handle virtual hosting 
I am sure this simple hack can be easily reproduced to use virtual hosting in some other Rest frameworks.
