In a nutshell, the long running problem that I and other developers have had with apache httpd is that when using mod_vhost_alias, the DOCUMENT_ROOT variable to the value of VirtualDocumentRoot as expected. The only way to change this behavior is to actually patch Apache yourself because for some reason I still can’t fathom, the Httpd refuse to fix. Read the thread to get the full drama. The most recent response has truly summed up the issue in a eloquent manner:
— Comment #24 from Tyler Havener <apachebugs@resonant.com> 2008-04-06 14:24:36 PST —
(In reply to comment #1)
I think the developers of mod_vhost_alias may be missing a few important
points. Here is my opinion on the situation, and some things to take into
consideration:
* There are “developers” of apache, there are users of apache (the
administrators who install it), and then there are developers of web solutions
that run on Apache. Though there are certainly some individuals that wear all
three hats, the underlying expectation should be that they would all be
different people who are not reliant on one another
* DOCUMENT_ROOT has no behavior. It is just an environment variable that is set
according to the behavior of a directives and their parameters
* Setting a VIRTUAL_DOCUMENT_ROOT environment variable is useless, because it
still requires users of the system to recode. And this fails to honor the
delineation that should exist (or should be offered) between a web server
administrator and the developer who builds apps to run on it.
* The DocumentRoot parameter has never done anything but establish the static
base from which customizations to the filesystem/URL namespace could occur
through the use of mod_userdir, mod_alias, mod_rewrite, etc. This is true
regardless of context (whether Server or VirtualHost)
* VirtualDocumentRoot is intended as replacement to DocumentRoot, for which the
only difference is the inclusion of a language the can be used to dynamically
determine where the aforementioned static base of files is. It should otherwise
behave in the same manner as that which it is to replace.
I think that developers often get caught up in semantics of code and functional
behavior in a way that easily overlooks what “should be done.” That
VirtualDocumentRoot does not set the DOCUMENT_ROOT variable is by design,
however, this is incorrect design. The semantics as to whether this is a bug is
up to you, but this issue is no less deserving of ”enhancement” than it is a
“major” one which prevents it from fulfilling its intended duty. Developers of
apps should not have to recode. Administrators should have the freedom to
structure their hosting environment how they see fit whenever possible.
In conclusion: VirtualDocumentRoot should set DOCUMENT_ROOT to the interpolated
directory.
