Apache HTTP Server Version 2.2
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This document supplements the mod_rewrite
reference documentation. It describes
how you can use mod_rewrite
to create dynamically
configured virtual hosts.
mod_rewrite
We want to automatically create a virtual host for every hostname which resolves in our domain, without having to create new VirtualHost sections.
In this recipe, we assume that we'll be using the hostname
www.SITE.example.com
for each
user, and serve their content out of
/home/SITE/www
.
RewriteEngine on
RewriteMap lowercase int:tolower
RewriteCond %{lowercase:%{HTTP_HOST}} ^www\.([^.]+)\.example\.com$
RewriteRule ^(.*) /home/%1/www$1
The internal tolower
RewriteMap directive is used to
ensure that the hostnames being used are all lowercase, so that there is
no ambiguity in the directory structure which must be created.
Parentheses used in a RewriteCond
are captured into the
backreferences %1
, %2
, etc, while parentheses
used in RewriteRule
are
captured into the backreferences $1
, $2
,
etc.
As with many techniques discussed in this document, mod_rewrite really
isn't the best way to accomplish this task. You should, instead,
consider using mod_vhost_alias
instead, as it will much
more gracefully handle anything beyond serving static files, such as any
dynamic content, and Alias resolution.
mod_rewrite
This extract from httpd.conf
does the same
thing as the first example. The first
half is very similar to the corresponding part above, except for
some changes, required for backward compatibility and to make the
mod_rewrite
part work properly; the second half
configures mod_rewrite
to do the actual work.
Because mod_rewrite
runs before other URI translation
modules (e.g., mod_alias
), mod_rewrite
must
be told to explicitly ignore any URLs that would have been handled
by those modules. And, because these rules would otherwise bypass
any ScriptAlias
directives, we must have
mod_rewrite
explicitly enact those mappings.
# get the server name from the Host: header
UseCanonicalName Off
# splittable logs
LogFormat "%{Host}i %h %l %u %t \"%r\" %s %b" vcommon
CustomLog logs/access_log vcommon
<Directory /www/hosts>
# ExecCGI is needed here because we can't force
# CGI execution in the way that ScriptAlias does
Options FollowSymLinks ExecCGI
</Directory>
RewriteEngine On
# a ServerName derived from a Host: header may be any case at all
RewriteMap lowercase int:tolower
## deal with normal documents first:
# allow Alias /icons/ to work - repeat for other aliases
RewriteCond %{REQUEST_URI} !^/icons/
# allow CGIs to work
RewriteCond %{REQUEST_URI} !^/cgi-bin/
# do the magic
RewriteRule ^/(.*)$ /www/hosts/${lowercase:%{SERVER_NAME}}/docs/$1
## and now deal with CGIs - we have to force a handler
RewriteCond %{REQUEST_URI} ^/cgi-bin/
RewriteRule ^/(.*)$ /www/hosts/${lowercase:%{SERVER_NAME}}/cgi-bin/$1 [H=cgi-script]
This arrangement uses more advanced mod_rewrite
features to work out the translation from virtual host to document
root, from a separate configuration file. This provides more
flexibility, but requires more complicated configuration.
The vhost.map
file should look something like
this:
customer-1.example.com /www/customers/1
customer-2.example.com /www/customers/2
# ...
customer-N.example.com /www/customers/N
The httpd.conf
should contain the following:
RewriteEngine on
RewriteMap lowercase int:tolower
# define the map file
RewriteMap vhost txt:/www/conf/vhost.map
# deal with aliases as above
RewriteCond %{REQUEST_URI} !^/icons/
RewriteCond %{REQUEST_URI} !^/cgi-bin/
RewriteCond ${lowercase:%{SERVER_NAME}} ^(.+)$
# this does the file-based remap
RewriteCond ${vhost:%1} ^(/.*)$
RewriteRule ^/(.*)$ %1/docs/$1
RewriteCond %{REQUEST_URI} ^/cgi-bin/
RewriteCond ${lowercase:%{SERVER_NAME}} ^(.+)$
RewriteCond ${vhost:%1} ^(/.*)$
RewriteRule ^/(.*)$ %1/cgi-bin/$1 [H=cgi-script]
Available Languages: en