gistfile1.sh

server {

   proxy_cache_path /var/nginx_cache/mycache levels=1:2 keys_zone=MYCACHE:5m inactive=12h max_size=20m;

   # The config is even for the non-www host later you will see how we manage the redirect
   server_name www.mysite.it mysite.it;
   listen 111.222.333.444:80;
   access_log    /var/log/nginx/nginx.mysite_it.log upstream;

   proxy_redirect     off;
   proxy_set_header   Host             $host;
   proxy_set_header   X-Real-IP        $remote_addr;
   proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
   proxy_store_access  user:rw  group:rw  all:r;
   
   # If the request is for the non-www host we redirect the client to the www version
   # Doing the redirect here at the NGINX level save some work to out backend 
   if ($host != 'www.mysite.it' ) {
       rewrite  ^/(.*)$  http://www.mysite.it/$1  permanent;
   }
   
   location / {
   
      # If logged in, don't cache. Feel free to add other cookies to the condition
      if ($http_cookie ~* "comment_author_|wordpress_(?!test_cookie)|wp-postpass_" ) {
         set $do_not_cache 1;
      }
      
      # Do not cache request from Facebook and Apple devices
      # If you don't have any mobile version of your site you can change the condition like
      #    if ($http_user_agent ~* "(facebookexternalhit)" ) 
      # I prefer to not cache request from Facebook so it can access always the freshest data 
      # Facebook has already a cache system, so you wont get useless load on the backend
      
      if ($http_user_agent ~* "(facebookexternalhit|2\.0 MMP|240x320|400X240|AvantGo|BlackBerry|Blazer|Cellphone|Danger|DoCoMo|Elaine\/3\.0|EudoraWeb|Googlebot-Mobile|hiptop|IEMobile|KYOCERA\/WX310K|LG\/U990|MIDP-2\.|MMEF20|MOT-V|NetFront|Newt|Nintendo Wii|Nitro|Nokia|Opera Mini|Palm|PlayStation Portable|portalmmm|Proxinet|ProxiNet|SHARP-TQ-GX10|SHG-i900|Small|SonyEricsson|Symbian OS|SymbianOS|TS21i-10|UP\.Browser|UP\.Link|webOS|Windows CE|WinWAP|YahooSeeker\/M1A1-R2D2|NF-Browser|iPhone|iPod|Android|BlackBerry9530|G-TU915 Obigo|LGE VX|webOS|Nokia5800)" ) {
         set $do_not_cache 1;
      }
   
      # We tell NGINX to do not cached the response   
      proxy_no_cache $do_not_cache;
      
      # Serve cached version during update or error (backend not available) 
      #
      # Serve cached pages while the cached version is getting updated is very important. 
      # In this way only the first request that hit an expired entry is passed to the backend, all the other get a stale version.
      proxy_cache_use_stale error timeout invalid_header updating;
      
      # Ignore Expires and Cache-Control headers to cache 404 response
      # Have a look at the bug/misfeature I've found http://www.ruby-forum.com/topic/3707266
      proxy_ignore_headers Expires Cache-Control;
      
      proxy_cache MYCACHE;
      
      proxy_pass http://ALL_backend;
      
   }

   # To make this works you need to install this module http://labs.frickle.com/nginx_ngx_cache_purge/
   location ~ /purge(/.*) {
      include sites/includes/allowed_ip_for_cache_purging.includes;
      proxy_cache_purge MYCACHE "$scheme://$host$1$is_args$args";
   }

   # Caching static files. 
   #
   # Please note the case-insensitive match and be sure to put this directive before the one for the wp-admin 
   # otherwise static files under in the admin interface are not cached
   
   location ~* \.(bmp|gif|jpg|png|css|jpeg|js|ico|eot|woff|ttf|svg)$ {
      proxy_pass http://ALL_backend;
      proxy_cache MYCACHE;
      proxy_ignore_headers Expires Cache-Control;
      proxy_cache_valid 200 302 301 404 7d;
      proxy_cache_use_stale error timeout invalid_header updating http_500 http_502 http_503 http_504;
      expires 7d;
      
      # Turn off access log for performance reasons. Feel free to turn this on.
      access_log off;
   }

   # Do not cache request for admin
   location ~* wp\-.*\.php|wp\-admin {
      proxy_pass http://ALL_ADMIN_backend;
   }

   # No access to .htaccess files.
   location ~ /\.ht {
      deny  all;
   }

}