Question

Do you know if i can (easly) “block” access to my production site for do an upgrade of code with symfony2 ?

Somthing like: All pages of my site display: “Site is in maintenance”.

Answer 1

Exact rules: .htaccess

RewriteEngine on
RewriteCond %{REQUEST_URI} !/maintenance.html$
RewriteRule $ /maintenance.html [R=302,L]

@ elnur: with juste

RewriteRule ^(.*)$ /path/to/the/maintenance/page.html 

we have infinite loop