[Varnish] #444: allow to handle non-GET req in vcl_miss

[Varnish]

#444: allow to handle non-GET req in vcl_miss
--------------------+-------------------------------------------------------
 Reporter:  hajile  |        Type:  enhancement
   Status:  new     |    Priority:  normal     
Milestone:          |   Component:  build      
  Version:  trunk   |    Severity:  normal     
 Keywords:          |  
--------------------+-------------------------------------------------------
 Right now the request is forcibly set to be 'GET'.

 As far as I understand the reason http_FilterHeader(sp, HTTPH_R_FETCH)
 forces request to be 'GET' is to correctly cache objects for 'HEAD'
 requests.
 This may be better done in default vcl or somewhere else.

 This is not complete patch, it works for me, but it'll break some setups.

 In essence, all this is needed to invalidate a cache object when
 POST/DELETE/PUT arrives. This is very useful feature to transparently
 cache REST-ful services, which are very popular today.

 See an example .vcl below, after patch sketch

 @@ -650,7 +660,7 @@
         CHECK_OBJ_NOTNULL(sp->obj, OBJECT_MAGIC);
         CHECK_OBJ_NOTNULL(sp->vcl, VCL_CONF_MAGIC);

 -       http_FilterHeader(sp, HTTPH_R_FETCH);
 +       http_FilterHeader(sp, HTTPH_R_PASS);
         VCL_miss_method(sp);
         AZ(sp->obj->cacheable);
         switch(sp->handling) {

 ----------------------------------------


 backend test {
  .host = "127.0.0.1";
  .port = "8081";
 }

 sub vcl_recv {
  if (req.request == "POST" || req.request == "PUT" || req.request ==
 "DELETE") {
   lookup;
  }
 }

 sub vcl_hit {
  if (req.request == "POST" || req.request == "PUT" || req.request ==
 "DELETE") {
   set obj.ttl = 0s;
   set obj.cacheable = false;
   pass;
  }
 }

 sub vcl_miss {
  if (req.request == "POST" || req.request == "PUT" || req.request ==
 "DELETE") {
   pass;
  }
 }

-- 
Ticket URL: <http://varnish.projects.linpro.no/ticket/444>
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