CodeIgniter Nginx Rewrite Rules

Minimum config for CodeIgniter Skeleton:

server {
    listen       80;
    server_name  www.example.com example.com;
    
    root /var/www/example.com/html;
    index index.php index.html index.htm;
    
    # Enable rewrite error log
    # error_log /var/log/nginx/localhost.error_log debug;
    # rewrite_log on;
    
    # Any HTTP request other than those for assets folder, files folder and robots.txt
    # is treated as a request for your index.php file.
    location ~* ^/(assets|files|robots\.txt) { }
    location / {
        try_files $uri $uri/ /index.php?/$request_uri;
    }
    
    # Pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    location ~ \.php$ {
        fastcgi_pass   127.0.0.1:9000;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  /var/www/example.com/html$fastcgi_script_name;
        include        fastcgi_params;
    }
    
    # Deny access to .htaccess files, if Apache's document root
    # concurs with Nginx's one
    location ~ /\.ht {
        deny  all;
    }
}