hgweb: support constructing URLs from an alternate base URL
The web.baseurl config option allows server operators to define a
custom URL for hosted content.
The way it works today is that hgwebdir parses this config
option into URL components then updates the appropriate
WSGI environment variables so the request "lies" about its
details. For example, SERVER_NAME is updated to reflect the
alternate base URL's hostname.
The WSGI environment should not be modified because WSGI
applications may want to know the original request details (for
debugging, etc).
This commit teaches our request parser about the existence of
an alternate base URL. If defined, the advertised URL and other
self-reflected paths will take the alternate base URL into account.
The hgweb WSGI application didn't use web.baseurl. But hgwebdir
did. We update hgwebdir to alter the environment parsing
accordingly. The old code around environment manipulation
has been removed.
With this change, parserequestfromenv() has grown to a bit
unwieldy. Now that practically everyone is using it, it is
obvious that there is some unused features that can be trimmed.
So look for this in follow-up commits.
Differential Revision: https://phab.mercurial-scm.org/D2822
#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories
# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"
# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
#import sys; sys.path.insert(0, "/path/to/python/lib")
# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()
from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi
application = hgweb(config)
wsgicgi.launch(application)