feature: implemented the balancer_by_lua_block and balancer_by_lua_file directives to allow NGINX load balancers written in Lua

Also added pure C API to support the ngx.balancer Lua API implemented in the lua-resty-core library.

Author: doujiang24

config

@@ -306,6 +306,7 @@ NGX_ADDON_SRCS="$NGX_ADDON_SRCS \
                 $ngx_addon_dir/src/ngx_stream_lua_directive.c \
                 $ngx_addon_dir/src/ngx_stream_lua_lex.c \
                 $ngx_addon_dir/src/ngx_stream_lua_contentby.c \
+                $ngx_addon_dir/src/ngx_stream_lua_balancer.c \
                 $ngx_addon_dir/src/ngx_stream_lua_util.c \
                 $ngx_addon_dir/src/ngx_stream_lua_cache.c \
                 $ngx_addon_dir/src/ngx_stream_lua_clfactory.c \
@@ -343,6 +344,7 @@ NGX_ADDON_DEPS="$NGX_ADDON_DEPS \
                 $ngx_addon_dir/src/ngx_stream_lua_common.h \
                 $ngx_addon_dir/src/ngx_stream_lua_lex.h \
                 $ngx_addon_dir/src/ngx_stream_lua_contentby.h \
+                $ngx_addon_dir/src/ngx_stream_lua_balancer.h \
                 $ngx_addon_dir/src/ngx_stream_lua_util.h \
                 $ngx_addon_dir/src/ngx_stream_lua_cache.h \
                 $ngx_addon_dir/src/ngx_stream_lua_clfactory.h \

src/api/ngx_stream_lua_api.h

@@ -19,7 +19,7 @@
 /* Public API for other Nginx modules */
 
 
-#define ngx_stream_lua_version  10001
+#define ngx_stream_lua_version  10006
 
 
 typedef struct {