Better Capistrano Rewrite Rule for Maintenance Page

Capistrano comes with a nice little tasked called deploy:web:disable that puts up a maintenance page on your site. Assuming your webserver detects the presence of this page and rewrites any requests to display that page, this effectively disables your site. Very handy.

I found that the common configuration available on the Internet didn't work for me. Specifically, the Apache Rewrite rule needs to reference DOCUMENT_ROOT. Here are my rewrite rules; remember that for this to work, they have to be first:

RewriteCond %{DOCUMENT_ROOT}system/maintenance.html -f
RewriteCond %{SCRIPT_FILENAME} !maintenance.html
RewriteRule ^.*$ %{DOCUMENT_ROOT}system/maintenance.html [L]