Redirect HTTP to HTTPS using Apache and Google Cloud Platform Loadbalancer

Using Apache to redirect HTTP to HTTP, if https version of the site is not configured via Apache ModSSL it doesn't set %{HTTPS} variable to "on" and keeps redirecting infinitely.

The best way to do is to send X-Forwarded-Proto header from load balancer to Apache and configure RewriteCond as follow.

If not already done enablerewrite and ssl

a2enmod rewrite
a2enmod ssl

Then in HTTP vhost configure

<VirtualHost *:80>
....

RewriteEngine On
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [QSA,L,R=301]

...

</VirtualHost>

Instead of the common usage :

RewriteCond %{HTTPS} off

source : https://stackoverflow.com/a/19722706