default.vcl

# This is a basic VCL configuration file for varnish.  See the vcl(7)
# man page for details on VCL syntax and semantics.
#
# Default backend definition.  Set this to point to your content
# server.
#

# Switch to 8080 when we go live.
backend default {
    .host = "127.0.0.1";
    .port = "8080";
}

sub vcl_recv {

  # Site specific
  if ( !(req.url ~ "^/favicon.ico" ||
      req.url ~ "^/scripts/" ||
      req.url ~ "^/assets/" ||
      req.url ~ "^/cache" ||
      req.url ~ "^/files/" ||
      req.url ~ "^/docs/.*" ||
      req.url ~ "^/cp/.*" ||
      req.http.Cookie ~ ".*exp_sessionid.*" ||
      req.request == "POST" ||
      req.http.X-Requested-With == "XMLHttpRequest" ) ){
      remove req.http.Cookie;
      remove req.http.Cache-Control;
      remove req.http.Max-Age;
      remove req.http.Pragma;
      set req.http.cacheme = "1";
  } else {
    return (pass);
  }

  return (lookup);
}

sub vcl_fetch {
  if (beresp.http.Cache-Control ~ "no-cache") {
     return (hit_for_pass);
  }

  if (beresp.status == 403) {
    set beresp.ttl = 0s;
    return (hit_for_pass);
  }

  if (beresp.status >= 500) {
    set beresp.ttl = 0s;
    return (hit_for_pass);
  }

  /* Remove expires headers and use cache-control for non-assets. */
  if ( !(beresp.http.Content-Type ~ ".*(javascript|css|image).*" )) {
     unset beresp.http.expires;
     set beresp.http.cache-control = "max-age=900";
  }

  if (req.http.cacheme ~ "1") {
    unset beresp.http.Cookie;
    unset beresp.http.Cache-Control;
    unset beresp.http.Max-Age;
    unset beresp.http.Pragma;
    set beresp.ttl = 1w;
  }

  /* marker for vcl_deliver to reset Age: */
  set beresp.http.magicmarker = "1";

  # Varnish determined the object was not cacheable
  if (beresp.ttl <= 0s) {
      set beresp.http.X-Cacheable = "NO:Not Cacheable";

  # You don't wish to cache content for logged in users
  } elsif (req.http.Cookie ~ "exp_sessionid") {
      set beresp.http.X-Cacheable = "NO:Got Session";
      return(hit_for_pass);

  # You are respecting the Cache-Control=private header from the backend
  } elsif (beresp.http.Cache-Control ~ "private") {
      set beresp.http.X-Cacheable = "NO:Cache-Control=private";
      return(hit_for_pass);

  # Varnish determined the object was cacheable
  } else {
      set beresp.http.X-Cacheable = "YES";
  }

  return(deliver);
}

sub vcl_deliver {
  # This is for debugging cache misses
  if (obj.hits > 0) {
    set resp.http.X-Cache = "HIT";
  } else {
    set resp.http.X-Cache = "MISS";
  }

  /* Set in vcl_fetch. for expires headers */
  if (resp.http.magicmarker) {
    /* Remove the magic marker */
    unset resp.http.magicmarker;

    /* By definition we have a fresh object */
    set resp.http.age = "0";
  }
}