# This is the vcl.conf file for andromeda.motd.be 
 
backend default {
     .host = "208.68.209.225";
     .port = "80";
}
 
#
# handling of request that are received from clients.
# decide whether or not to lookup data in the cache first.
# if we have multiple backends, we could specify them here but for now there is just the default
#
sub vcl_recv {
     # If the client sent an X-Forwarded-For header, remove it. It cannot be trusted.
     unset req.http.X-Forwarded-For;
     # Note that we don't need to add the client ip to the X-Forwarded-For header, varnish will do that for us
 
     if (req.http.Accept-Encoding) {
          # Handle compression correctly. Varnish treats headers literally, not
          # semantically. So it is very well possible that there are cache misses
          # because the headers sent by different browsers aren't the same.
          # @see: http:// varnish.projects.linpro.no/wiki/FAQ/Compression
          if (req.http.Accept-Encoding ~ "gzip") {
               # if the browser supports it, we'll use gzip
               set req.http.Accept-Encoding = "gzip";
          } elsif (req.http.Accept-Encoding ~ "deflate") {
               # next, try deflate if it is supported
               set req.http.Accept-Encoding = "deflate";
          } else {
               # unknown algorithm. Probably junk, remove it
               unset req.http.Accept-Encoding;
          }
     }
 
     # If we get a request for a page that has just been requested by another thread and
     # is still being fetched from the backend, allow serving a cached page so long as it hasn't
     # expired more than 30 seconds ago (prevents thread pileup on cache refreshes).
     # Note that this only works if obj.grace is also set:
     #     "If no in-ttl object was found AND we have a graced object AND it is also
     #      graced by req.grace AND it is being fetched: serve the graced object."
     set req.grace = 30s;
 
     # the default vcl_recv will only look up objects in the cache if there is no cookie
     # present in the request. Therefor, we remove the cookie header from all requests for
     # files which we know to be static.
     #
     # These are drupal-specific:
     # - everything in most of the standard drupal directories.
     # - txt and ico files (most important: robots.txt and favicon.ico)
     if (req.url ~ "^/(files|misc|sites|themes|modules)/" || req.url ~ "\.(txt|ico)$") {
         unset req.http.Cookie; 
     }
 
     # No final action. Continues in the default vcl_recv which will only look up
     # items from the cache for GET and HEAD requests without cookies.
}
 
#
# Called when entering pipe mode
#
sub vcl_pipe {
     # If we don't set the Connection: close header, any following
     # requests from the client will also be piped through and
     # left untouched by varnish. We don't want that.
     set req.http.connection = "close";
 
     # Note: no "pipe" action here - we'll fall back to the default
     # pipe method so that when any changes are made there, we
     # still inherit them.
}
 
#
# Called when the requested object has been retrieved from the
# backend, or the request to the backend has failed
#
sub vcl_fetch {
     if (obj.http.Pragma ~ "no-cache" || obj.http.Cache-Control ~ "(no-cache|no-store|private)") {
          # varnish by default ignores Pragma and Cache-Control headers. It
          # only looks at the "max-age=" value in the Cache-Control header to
          # determine the TTL. So we need this rule so that the cache respects
          # the wishes of the backend application.
          pass;
     }
 
     if (obj.ttl < 180s) {
          # force minimum ttl of 3 minutes for all cached objects.
          set obj.ttl = 180s;
     }
 
     # set the grace period for this object to a maximum of 30s. This is how
     # long after its expire time, it is still allowed to be served from cache if
     # directed to do so by vcl_recv. 
     set obj.grace = 30s;
 
     if (req.http.Authorization && !obj.http.Cache-Control ~ "public") {
          # don't allow caching pages that are protected by basic authentication
          # unless when they explicitly set the cache-control to public.
          pass;
     }
 
     # Note: no final action - continue in the default vcl_fetch
}