Support K8S hostname auto discovery cluster

etc/emqx.conf

@@ -145,7 +145,7 @@ cluster.autoclean = 5m
 
 ## The address type is used to extract host from k8s service.
 ##
-## Value: ip | dns
+## Value: ip | dns | hostname
 ## cluster.k8s.address_type = ip
 
 ## The app name helps build 'node.name'.
@@ -153,6 +153,11 @@ cluster.autoclean = 5m
 ## Value: String
 ## cluster.k8s.app_name = emqx
 
+## The suffix added to hostname get from k8s service, only valid if cluster.k8s.address_type set to hostname
+##
+## Value: String
+## cluster.k8s.hostname_suffix =
+
 ## Kubernates Namespace
 ##
 ## Value: String

priv/emqx.schema

@@ -129,7 +129,7 @@
 ]}.
 
 {mapping, "cluster.k8s.address_type", "ekka.cluster_discovery", [
-  {datatype, {enum, [ip, dns]}}
+  {datatype, {enum, [ip, dns, hostname]}}
 ]}.
 
 {mapping, "cluster.k8s.app_name", "ekka.cluster_discovery", [
@@ -140,6 +140,11 @@
   {datatype, string}
 ]}.
 
+{mapping, "cluster.k8s.hostname_suffix", "ekka.cluster_discovery", [
+    {datatype, string},
+    {default, ""}
+  ]}.
+
 {translation, "ekka.cluster_discovery", fun(Conf) ->
   Strategy = cuttlefish:conf_get("cluster.discovery", Conf),
   Filter  = fun(Opts) -> [{K, V} || {K, V} <- Opts, V =/= undefined] end,
@@ -176,7 +181,8 @@
                   {service_name, cuttlefish:conf_get("cluster.k8s.service_name", Conf)},
                   {address_type, cuttlefish:conf_get("cluster.k8s.address_type", Conf, ip)},
                   {app_name, cuttlefish:conf_get("cluster.k8s.app_name", Conf)},
-                  {namespace, cuttlefish:conf_get("cluster.k8s.namespace", Conf)}];
+                  {namespace, cuttlefish:conf_get("cluster.k8s.namespace", Conf)},
+                  {hostname_suffix, cuttlefish:conf_get("cluster.k8s.hostname_suffix", Conf, "")}];
                (manual) ->
                  [ ]
             end,

rebar.config

@@ -4,7 +4,7 @@
      {gproc, "0.8.0"}, % hex
      {replayq, "0.1.1"}, %hex
      {esockd, "5.5.0"}, %hex
-     {ekka, {git, "https://github.com/emqx/ekka", {tag, "v0.5.7"}}},
+     {ekka, {git, "https://github.com/emqx/ekka", {branch, "master"}}},
      {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "2.3.1"}}},
      {cuttlefish, {git, "https://github.com/emqx/cuttlefish", {tag, "v3.0.0"}}}
     ]}.