Add the extra_fields.lua module
This commit adds the extra_fields Lua module. The extra fields table defined in
this module is empty right now. Eventually, this file will be a Jinja2 template
and the content of the extra fields table will be generated based on the user
configuration.
diff --git a/heka/files/lua/common/extra_fields.lua b/heka/files/lua/common/extra_fields.lua
new file mode 100644
index 0000000..d75fdc7
--- /dev/null
+++ b/heka/files/lua/common/extra_fields.lua
@@ -0,0 +1,20 @@
+-- Copyright 2015 Mirantis, Inc.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+-- http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+local M = {}
+setfenv(1, M) -- Remove external access to contain everything in the module
+
+-- list of fields that are added to Heka messages by the collector
+tags = {}
+
+return M