Fix issue #1460 - Add node.proto_dist option to support inet6_dist

etc/emq.conf

@@ -231,6 +231,15 @@ node.fullsweep_after = 1000
 ## Value: Log file
 node.crash_dump = {{ platform_log_dir }}/crash.dump
 
+## Specify the erlang distributed protocol.
+##
+## Value: Enum
+##  - inet_tcp: the default; handles TCP streams with IPv4 addressing.
+##  - inet6_tcp: handles TCP with IPv6 addressing.
+##
+## vm.args: -proto_dist inet_tcp
+## node.proto_dist = inet_tcp
+
 ## Sets the net_kernel tick time. TickTime is specified in seconds.
 ## Notice that all communicating nodes are to have the same TickTime
 ## value specified.

priv/emq.schema

@@ -168,6 +168,11 @@ end}.
   {default, "emq@127.0.0.1"}
 ]}.
 
+%% @doc The erlang distributed protocol
+{mapping, "node.proto_dist", "vm_args.-proto_dist", [
+  %%{default, "inet_tcp"}
+]}.
+
 %% @doc Secret cookie for distributed erlang node
 {mapping, "node.cookie", "vm_args.-setcookie", [
   {default, "emqsecretcookie"}