It is really simple using .htaccess with mod_rewrite.
Here is all you need:
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://site.com/$1 [R=301,L]
Another more graceful way is to use the %{SERVER_NAME}variable to make it dynamic. Just be careful that the server name will always match what you expect. (eg. if you are doing load balancing or clustering what if the server name may be somethi........