[Minor] Add function to load redis server config in C using lua_redis

src/lua/lua_common.c

@@ -2343,3 +2343,64 @@ rspamd_lua_require_function (lua_State *L, const gchar *modname,
 
 	return FALSE;
 }
+
+
+gboolean
+rspamd_lua_try_load_redis (lua_State *L, const ucl_object_t *obj,
+									struct rspamd_config *cfg, gint *ref_id)
+{
+	gint res_pos, err_idx;
+	struct rspamd_config **pcfg;
+
+	/* Create results table */
+	lua_createtable (L, 0, 0);
+	res_pos = lua_gettop (L);
+	lua_pushcfunction (L, &rspamd_lua_traceback);
+	err_idx = lua_gettop (L);
+
+	/* Obtain function */
+	if (!rspamd_lua_require_function (L, "lua_redis", "try_load_redis_servers")) {
+		msg_err_config ("cannot require lua_redis");
+		lua_pop (L, 2);
+
+		return FALSE;
+	}
+
+	/* Function arguments */
+	ucl_object_push_lua (L, obj, true);
+	pcfg = lua_newuserdata (L, sizeof (*pcfg));
+	rspamd_lua_setclass (L, "rspamd{config}", -1);
+	*pcfg = cfg;
+	lua_pushvalue (L, res_pos);
+
+	if (lua_pcall (L, 0, 1, err_idx) != 0) {
+		GString *tb;
+
+		tb = lua_touserdata (L, -1);
+		msg_err_config ("cannot call lua try_load_redis_servers script: %s", tb->str);
+		g_string_free (tb, TRUE);
+		lua_settop (L, 0);
+
+		return FALSE;
+	}
+
+	if (lua_toboolean (L, -1)) {
+		if (ref_id) {
+			/* Ref table */
+			lua_pushvalue (L, res_pos);
+			*ref_id = luaL_ref (L, LUA_REGISTRYINDEX);
+			lua_settop (L, 0);
+		}
+		else {
+			/* Leave it on the stack */
+			lua_settop (L, res_pos);
+		}
+
+		return TRUE;
+	}
+	else {
+		lua_settop (L, 0);
+	}
+
+	return FALSE;
+}

src/lua/lua_common.h

@@ -423,6 +423,16 @@ void rspamd_lua_add_ref_dtor (lua_State *L, rspamd_mempool_t *pool,
 gboolean rspamd_lua_require_function (lua_State *L, const gchar *modname,
 		const gchar *funcname);
 
+/**
+ * Tries to load redis server definition from ucl object specified
+ * @param L
+ * @param obj
+ * @param cfg
+ * @return
+ */
+gboolean rspamd_lua_try_load_redis (lua_State *L, const ucl_object_t *obj,
+		struct rspamd_config *cfg, gint *ref_id);
+
 /* Paths defs */
 #define RSPAMD_CONFDIR_INDEX "CONFDIR"
 #define RSPAMD_LOCAL_CONFDIR_INDEX "LOCAL_CONFDIR"