Apacheでhttpをhttpsへリダイレクトする設定です。
mod_rewriteを使います。
<VirtualHost *:80>
    ServerName www.example.com
    <ifModule mod_rewrite.c>
        RewriteEngine On
        LogLevel alert rewrite:trace3
        RewriteCond %{HTTPS} off
        RewriteCond %{HTTP_HOST} !=localhost
        RewriteCond %{HTTP_HOST} !=127.0.0.1
        RewriteCond %{HTTP_HOST} !=::1
        RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R,L]
    </ifModule>
</VirtualHost>