title: nginx change root folder for specific url
body: <p>I have a configuration file like this one below:</p>
  
  <pre>
      server {
  
          listen       80;
          server_name  localhost;
  
          #charset utf-8;
          root   html/laravel/public;
          index  index.html index.php;
  
          #browse folders if no index file
          autoindex on;
  
          # enforce NO www
          if ($host ~* ^www\.(.*))
          {
              set $host_without_www $1;
              rewrite ^/(.*)$ $scheme://$host_without_www/$1 permanent;
          }
  
          # serve static files directly
          location ~* \.(jpg|jpeg|gif|css|png|js|ico|html)$ {
              access_log off;
              #expires max;
          }
  
          # removes trailing slashes (prevents SEO duplicate content issues)
          if (!-d $request_filename)
          {
              rewrite ^/(.+)/$ /$1 permanent;
          }
  
          # canonicalize codeigniter url end points
          # if your default controller is something other than "welcome" you should change the following
          # if ($request_uri ~* ^(/lobby(/index)?|/index(.php)?)/?$)
          # {
          #     rewrite ^(.*)$ / permanent;
          # }
  
          # removes trailing "index" from all controllers
          if ($request_uri ~* index/?$)
          {
              rewrite ^/(.*)/index/?$ /$1 permanent;
          }
  
          # unless the request is for a valid file (image, js, css, etc.), send to bootstrap
          if (!-e $request_filename)
          {
              rewrite ^/(.*)$ /index.php?/$1 last;
              break;
          }
  
          # redirect server error pages to the static page /50x.html
          #
          error_page   500 502 503 504  /50x.html;
          location = /50x.html {
              root   html;
          }
  
          location /backend/ {
              root /html/frontend;
          }
  
          location ~ \.php$ {
              include fastcgi.conf;
              fastcgi_pass 127.0.0.1:9000;
              fastcgi_index index.php;
              include fastcgi_params;
          }
  
          location ~ /\.ht {
              deny  all;
          }
  
          # catch all
          # error_page 404 /index.php;
  
          # location ~ \.php$ {
          # try_files $uri =404;
          #         fastcgi_pass  unix:/tmp/php.socket;
          #         fastcgi_index index.php;
          #         #include fastcgi_params;
          #         include /home/tamer/code/nginx/fastcgi_params;
          # }
          # access_log /home/tamer/code/laravel/storage/logs.access.log;
          # error_log  /home/tamer/code/laravel/storage/logs.error.log;
      }
  </pre>
  
  <p>I have to change root folder to <code>html/backend</code> for any url with <code>$host/backend/</code>. All rules for load pages have to be the same, only root folder have to change.</p>
  
  <p>How can I do that?</p>