es_out: support Upstream Servers with configuration overriding

include/fluent-bit/flb_lib.h

@@ -23,6 +23,8 @@
 #include <fluent-bit/flb_macros.h>
 #include <fluent-bit/flb_config.h>
 
+struct flb_input_instance;
+
 /* Lib engine status */
 #define FLB_LIB_ERROR     -1
 #define FLB_LIB_NONE       0
@@ -69,7 +71,14 @@ FLB_EXPORT int flb_output_set_test(flb_ctx_t *ctx, int ffd, char *test_name,
                                    void (*out_callback) (void *, int, int,
                                                          void *, size_t, void *),
                                    void *out_callback_data,
-                                   void *test_ctx);
+                                   void *flush_ctx);
+FLB_EXPORT int flb_output_set_test_flush_ctx_callback(flb_ctx_t *ctx, int ffd,
+                                                      char *test_name,
+                                                      void *(*flush_ctx_callback)(
+                                                              struct flb_config *,
+                                                              struct flb_input_instance *,
+                                                              void *, void *),
+                                                      void *flush_ctx);
 FLB_EXPORT int flb_output_set_callback(flb_ctx_t *ctx, int ffd, char *name,
                                        void (*cb)(char *, void *, void *));
 FLB_EXPORT int flb_output_set_http_test(flb_ctx_t *ctx, int ffd, char *test_name,

include/fluent-bit/flb_output.h

@@ -151,9 +151,24 @@ struct flb_test_out_formatter {
      */
     void *rt_data;
 
-    /* optional context for flush callback */
+    /* optional context for "flush context callback" */
     void *flush_ctx;
 
+    /*
+     * Callback
+     * =========
+     * Optional "flush context callback": it references the function that extracts
+     * optional flush context for "formatter callback".
+     */
+    void *(*flush_ctx_callback) (/* Fluent Bit context */
+                                 struct flb_config *,
+                                 /* plugin that ingested the records */
+                                 struct flb_input_instance *,
+                                 /* plugin instance context */
+                                 void *plugin_context,
+                                 /* context for "flush context callback" */
+                                 void *flush_ctx);
+
     /*
      * Callback
      * =========

plugins/out_es/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(src
   es_bulk.c
+  es_conf_parse.c
   es_conf.c
   es.c
   murmur3.c)