Problem with post_action when used with return 202; and POST request

[Pyry Hakulinen]

> Thank you for your report.  Please try the attached patch.

Thank you, the patch appears to be working fine, but because it
discards the request body, it isn't going to work for our use case.

Our use case is, to POST data to nginx and let nginx asynchronously
proxy it to somewhere else for processing, while freeing the client
that did the POSTing to do other things.

I think the request body should be transferred to post_action
location, and the location can then decide if it needs it or not.
Attached is a patch against 1.0.5 that reads the body if post_action
is used, but I'm not really sure if it's correct. My nginx-fu is still
a bit lacking.

Thanks,
Pyry
-------------- next part --------------
diff -r -u nginx-1.0.5.orig/src//http/modules/ngx_http_empty_gif_module.c nginx-1.0.5.ihazfix/src/http/modules/ngx_http_empty_gif_module.c
--- nginx-1.0.5.orig/src//http/modules/ngx_http_empty_gif_module.c	2010-06-18 18:17:07.000000000 +0300
+++ nginx-1.0.5.ihazfix/src/http/modules/ngx_http_empty_gif_module.c	2011-08-11 09:02:57.282004002 +0300
@@ -111,19 +111,12 @@
 static ngx_int_t
 ngx_http_empty_gif_handler(ngx_http_request_t *r)
 {
-    ngx_int_t                 rc;
     ngx_http_complex_value_t  cv;
 
     if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) {
         return NGX_HTTP_NOT_ALLOWED;
     }
 
-    rc = ngx_http_discard_request_body(r);
-
-    if (rc != NGX_OK) {
-        return rc;
-    }
-
     ngx_memzero(&cv, sizeof(ngx_http_complex_value_t));
 
     cv.value.len = sizeof(ngx_empty_gif);
diff -r -u nginx-1.0.5.orig/src//http/ngx_http_core_module.c nginx-1.0.5.ihazfix/src/http/ngx_http_core_module.c
--- nginx-1.0.5.orig/src//http/ngx_http_core_module.c	2011-04-19 15:29:16.000000000 +0300
+++ nginx-1.0.5.ihazfix/src/http/ngx_http_core_module.c	2011-08-11 14:05:59.308273425 +0300
@@ -1760,6 +1760,16 @@
     ngx_buf_t    *b;
     ngx_chain_t   out;
 
+    ngx_http_core_loc_conf_t  *clcf;
+
+    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
+
+    if (clcf->post_action.data == NULL) {
+        if (ngx_http_discard_request_body(r) != NGX_OK) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+    }
+
     r->headers_out.status = status;
 
     if (status == NGX_HTTP_NO_CONTENT) {
diff -r -u nginx-1.0.5.orig/src//http/ngx_http_request.c nginx-1.0.5.ihazfix/src/http/ngx_http_request.c
--- nginx-1.0.5.orig/src//http/ngx_http_request.c	2011-04-04 15:26:53.000000000 +0300
+++ nginx-1.0.5.ihazfix/src/http/ngx_http_request.c	2011-08-11 14:09:50.728612844 +0300
@@ -48,6 +48,7 @@
 static void ngx_http_keepalive_handler(ngx_event_t *ev);
 static void ngx_http_set_lingering_close(ngx_http_request_t *r);
 static void ngx_http_lingering_close_handler(ngx_event_t *ev);
+static void ngx_http_post_action_read_callback(ngx_http_request_t *r);
 static ngx_int_t ngx_http_post_action(ngx_http_request_t *r);
 static void ngx_http_close_request(ngx_http_request_t *r, ngx_int_t error);
 static void ngx_http_free_request(ngx_http_request_t *r, ngx_int_t error);
@@ -2863,20 +2864,15 @@
     return ngx_http_output_filter(r, &out);
 }
 
-
-static ngx_int_t
-ngx_http_post_action(ngx_http_request_t *r)
+static void
+ngx_http_post_action_read_callback(ngx_http_request_t *r)
 {
     ngx_http_core_loc_conf_t  *clcf;
 
     clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
 
-    if (clcf->post_action.data == NULL) {
-        return NGX_DECLINED;
-    }
-
-    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                   "post action: \"%V\"", &clcf->post_action);
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "post action read callback");
 
     r->main->count--;
 
@@ -2893,9 +2889,25 @@
         ngx_http_named_location(r, &clcf->post_action);
     }
 
-    return NGX_OK;
+    return;
 }
 
+static ngx_int_t
+ngx_http_post_action(ngx_http_request_t *r)
+{
+    ngx_http_core_loc_conf_t  *clcf;
+
+    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
+
+    if (clcf->post_action.data == NULL) {
+        return NGX_DECLINED;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "post action: \"%V\"", &clcf->post_action);
+
+    return ngx_http_read_client_request_body(r, ngx_http_post_action_read_callback);
+}
 
 static void
 ngx_http_close_request(ngx_http_request_t *r, ngx_int_t rc)