#
# Customized VCL file for serving up a Drupal site with multiple back-ends.
#
# For more information on this VCL, visit the Lullabot article:
# http://www.lullabot.com/articles/varnish-multiple-web-servers-drupal
#

# Define the internal network subnet.
# These are used below to allow internal access to certain files while not
# allowing access from the public internet.
acl internal {
  "127.0.0.1";
  "localhost";
}



backend default {
  .host = "127.0.0.1";
  .port = "8080";
  .connect_timeout = 600s;
  .first_byte_timeout = 600s;
  .between_bytes_timeout = 600s;
# enable to use status script for health of backend
#  .probe = { .url = "/status.php"; .interval = 5s; .timeout = 1s; .window = 5;.threshold = 3; }
}

# Respond to incoming requests.
sub vcl_recv {

  # reject malicious requests
  if (client.ip ~ blacklisted) {
          error 503 "Your IP has been blocked.";
     }


  # Allow the backend to serve up stale content if it is responding slowly.
  set req.grace = 6h;

  # Do not cache these paths.
  if (req.url ~ "^/status\.php$" ||
      req.url ~ "^/update\.php$" ||
      req.url ~ "^/ooyala/ping$" ||
      req.url ~ "^/admin/build/features" ||
      req.url ~ "^/info/.*$" ||
      req.url ~ "^/flag/.*$" ||
      req.url ~ "^.*/ajax/.*$" ||
      req.url ~ "^/phpMyAdmin/.*$" ||
      req.url ~ "^.*/ahah/.*$") {
       return (pass);
  }
  

  # Pipe these paths directly to Apache for streaming.
  if (req.url ~ "^/admin/content/backup_migrate/export") {
    return (pipe);
  }

  # Do not allow outside access to cron.php or install.php.
  if (req.url ~ "^/(cron|install)\.php$" && !client.ip ~ internal) {
    # Have Varnish throw the error directly.
    error 404 "Page not found.";
    # Use a custom error page that you've defined in Drupal at the path "404".
    # set req.url = "/404";
  }


  # Handle compression correctly. Different browsers send different
  # "Accept-Encoding" headers, even though they mostly all support the same
  # compression mechanisms. By consolidating these compression headers into
  # a consistent format, we can reduce the size of the cache and get more hits.=
  # @see: http:// varnish.projects.linpro.no/wiki/FAQ/Compression
  if (req.http.Accept-Encoding) {
    if (req.http.Accept-Encoding ~ "gzip") {
      # If the browser supports it, we'll use gzip.
      set req.http.Accept-Encoding = "gzip";
    }
    else if (req.http.Accept-Encoding ~ "deflate") {
      # Next, try deflate if it is supported.
      set req.http.Accept-Encoding = "deflate";
    }
    else {
      # Unknown algorithm. Remove it and send unencoded.
      unset req.http.Accept-Encoding;
    }
  }

  if ((!(req.url ~ 
"(^/(admin|users|cache|misc|modules|sites|system|openid|themes|node/add|node/*/edit|user/*|workspace|imce))|(/(comment/reply|edit|logout|user|user/(login|password|register))$)")) && 
(!(req.http.Cookie ~ "(VARNISH|DRUPAL_UID|LOGGED_IN|SESS)")))
	{
	unset req.http.Cookie;
  }
  
  # Always cache the following file types for all users.
  if (req.url ~ "(?i)\.(png|gif|jpeg|jpg|ico|swf|css|js|html|htm|pdf|doc)(\?[a-z0-9]+)?$") {
    unset req.http.Cookie;
  }

  # Remove all cookies that Drupal doesn't need to know about. ANY remaining
  # cookie will cause the request to pass-through to Apache. For the most part
  # we always set the NO_CACHE cookie after any POST request, disabling the
  # Varnish cache temporarily. The session cookie allows all authenticated users
  # to pass through as long as they're logged in.

  if (req.http.Cookie) {
  
  # Specifically remove Google analytics and Piwik cookies
  set req.http.Cookie = regsuball(req.http.Cookie, "(^|; ) *__utm.=[^;]+;? *", "\1"); # removes all cookies named __utm? (utma, utmb...)
  set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(_pk_(ses|id)[\.a-z0-9]*)=[^;]*", ""); # removes Piwik cookies

    # Don't cache Drupal logged-in user sessions
  # LOGGED_IN is the cookie that earlier version of Pressflow sets
  # VARNISH is the cookie which the varnish.module sets
  if (req.http.Cookie ~ "(VARNISH|DRUPAL_UID|LOGGED_IN)") {
	return (pass);
  }
  
  elseif (!(req.http.Cookie ~ "(VARNISH|DRUPAL_UID|LOGGED_IN)")) {
  
    set req.http.Cookie = ";" req.http.Cookie;
    set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
    set req.http.Cookie = regsuball(req.http.Cookie, ";(SESS[a-z0-9]+|NO_CACHE)=", "; \1=");
    set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
    set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");

    if (req.http.Cookie == "") {
      # If there are no remaining cookies, remove the cookie header. If there
      # aren't any cookie headers, Varnish's default behavior will be to cache
      # the page.
      unset req.http.Cookie;
    }

	
	
    else {
      # If there is any cookies left (a session or NO_CACHE cookie), do not
      # cache the page. Pass it on to Apache directly.
      return (pass);
    }
  }
  }

}

# Routine used to determine the cache key if storing/retrieving a cached page.
sub vcl_hash {
  # Include cookie in cache hash.
  # This check is unnecessary because we already pass on all cookies.
  # if (req.http.Cookie) {
  #   set req.hash += req.http.Cookie;
  # }
}

# Code determining what to do when serving items from the Apache servers.
sub vcl_fetch {
  # Don't allow static files to set cookies.
  if (req.url ~ "(?i)\.(png|gif|jpeg|jpg|ico|swf|css|js|html|htm|pdf|doc)(\?[a-z0-9]+)?$") {
    # beresp == Back-end response from the web server.
    unset beresp.http.set-cookie;
  }

  # Allow items to be stale if needed.
  set beresp.grace = 6h;
  # Serve the good page from the cache and re-check in one minute
  if (beresp.status == 503 || beresp.status == 501 || beresp.status == 500) {
    set beresp.grace = 60s;
    restart;
  }
  
  # Anything that is cacheable, but has expiration date too low which prevents caching gets cached by varnish to take 
  # the load off apache.
  if (beresp.cacheable && beresp.ttl < 1h) {
##### MINIMUM CACHE LIFETIME: Change this to your needs
    # Set how long Varnish will keep it
    set beresp.ttl = 30m;
##### END MINIMUM CACHE LIFETIME: Change this to your needs
    # marker for vcl_deliver to reset Age:
    set beresp.http.magicmarker = "1";
  }

}

sub vcl_deliver {
### START DEBUG
  if (obj.hits > 0) {
    set resp.http.X-Varnish-Cache = "HIT Varnish (" obj.hits ")";
  }
  else {
    set resp.http.X-Varnish-Cache = "MISS";
  }
  set resp.http.X-Varnish-Debug-Hits = obj.hits;
  set resp.http.X-Varnish-Debug-Age = resp.http.age;
### END DEBUG
  # The magic marker is used to reset the age to 0 as else the object is older than its ttl.
  if (resp.http.magicmarker) {
    # Remove the magic marker
    unset resp.http.magicmarker;
    # By definition we have a fresh object
    set resp.http.Age = "0";
  }
}


# In the event of an error, show friendlier messages.
sub vcl_error {
  # Redirect to some other URL in the case of a homepage failure.
  #if (req.url ~ "^/?$") {
  #  set obj.status = 302;
  #  set obj.http.Location = "http://backup.example.com/";
  #}

  # Otherwise redirect to the homepage, which will likely be in the cache.
  set obj.http.Content-Type = "text/html; charset=utf-8";
  synthetic {"
	# Error page html usually here
"};
  return (deliver);
}