I have a VPS with a Rails 4 application running on Ubuntu, NginX and Unicorn. As I want all pages to be SSL encrypted, all requests to `http://` are forwarded to `https://` which is working fine. This is an excerpt of my NginX configuration:

    
http {
        
        ....

        server {
                listen 80;
                server_name example.com;
                rewrite ^ https://$server_name$request_uri? permanent;
        }

        server {
                listen 443;
                server_name example.com;
                root /home/rails/public;
                index index.htm index.html;

                ssl on;
                ssl_certificate /etc/ssl/example.com.crt;
                ssl_certificate_key /etc/ssl/example.com.key;

                location / {
                        try_files $uri/index.html $uri.html $uri @app;
                }

                location @app {
                        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                        proxy_set_header X-Forwarded-Proto $scheme;
                        proxy_set_header Host $host;
                        proxy_pass http://app_server;
                 }
        }
}

How can I make it that all requests to `http://example.com` and `https://example.com` are forwarded to `https://www.example.com`? Thanks for any help.