Fix #754 - "-heart" option for EMQ 2.0

etc/emq.conf

@@ -11,9 +11,10 @@ node.cookie = emq_dist_cookie
 ## SMP support: enable, auto, disable
 node.smp = auto
 
-## TODO: -heart Heartbeat monitoring of an Erlang runtime system
-## Values: on | off
-## node.heartbeat = off
+## vm.args: -heart
+## Heartbeat monitoring of an Erlang runtime system
+## Value should be 'on' or comment the line
+## node.heartbeat = on
 
 ## Enable kernel poll
 node.kernel_poll = on

priv/emq.schema

@@ -24,10 +24,17 @@
 
 %% @doc http://erlang.org/doc/man/heart.html
 {mapping, "node.heartbeat", "vm_args.-heart", [
-  {datatype, {enum, [enable, auto, disable]}},
+  {datatype, flag},
   hidden
 ]}.
 
+{translation, "vm_args.-heart", fun(Conf) ->
+    case cuttlefish:conf_get("node.heartbeat", Conf) of
+        true  -> "";
+        false -> cuttlefish:invalid("should be 'on' or comment the line!")
+    end
+end}.
+
 %% @doc Enable Kernel Poll
 {mapping, "node.kernel_poll", "vm_args.+K", [
   {default, on},