feature: added the balancer_status_code patch to the nginx core to allow returning arbitrary HTTP status codes inside upstream balancers.

Signed-off-by: Yichun Zhang (agentzh) <agentzh@gmail.com>

patches/nginx-1.11.2-balancer_status_code.patch

@@ -0,0 +1,27 @@
+diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
+index 0f6b3ae..56d44fc 100644
+--- a/src/http/ngx_http_upstream.c
++++ b/src/http/ngx_http_upstream.c
+@@ -1368,6 +1368,11 @@ ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
+         return;
+     }
+ 
++    if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
++        ngx_http_upstream_finalize_request(r, u, rc);
++        return;
++    }
++
+     u->state->peer = u->peer.name;
+ 
+     if (rc == NGX_BUSY) {
+diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
+index b288f28..9b60e12 100644
+--- a/src/http/ngx_http_upstream.h
++++ b/src/http/ngx_http_upstream.h
+@@ -418,5 +418,6 @@ extern ngx_module_t        ngx_http_upstream_module;
+ extern ngx_conf_bitmask_t  ngx_http_upstream_cache_method_mask[];
+ extern ngx_conf_bitmask_t  ngx_http_upstream_ignore_headers_masks[];
+ 
++#define HAVE_BALANCER_STATUS_CODE_PATCH
+ 
+ #endif /* _NGX_HTTP_UPSTREAM_H_INCLUDED_ */

util/mirror-tarballs

@@ -55,6 +55,13 @@ else
     fi
 fi
 
+answer=`$root/util/ver-ge "$main_ver" 1.11.2`
+if [ "$answer" = "Y" ]; then
+    echo "$info_txt applying the balancer_status_code patch"
+    patch -p1 < $root/patches/nginx-$main_ver-balancer_status_code.patch || exit 1
+    echo
+fi
+
 answer=`$root/util/ver-ge "$main_ver" 1.11.2`
 if [ "$answer" = "Y" ]; then
     echo "$info_txt applying the builtin_error_page_footer patch"