Remove hard-coding of cluster domain

[sjgiri]

Currently, the template definition svc-domain hardcodes
the cluster domain to be cluster.local. For environments where
the cluster domain suffix could be different, hdfs chart does not
work.
The following can be a potential fix.

diff --git a/charts/hdfs-k8s/templates/_helpers.tpl b/charts/hdfs-k8s/templates/_helpers.tpl
index 9d03c4d..84803db 100644
--- a/charts/hdfs-k8s/templates/_helpers.tpl
+++ b/charts/hdfs-k8s/templates/_helpers.tpl
@@ -163,7 +163,7 @@ The HDFS config file should specify FQDN of services. Otherwise, Kerberos
 login may fail.
 */}}
 {{- define "svc-domain" -}}
-{{- printf "%s.svc.cluster.local" .Release.Namespace -}}
+{{- printf "%s.svc.%s" .Release.Namespace .Values.global.cluster_domain_suffix -}}
 {{- end -}}
 
 {{/*
diff --git a/charts/hdfs-k8s/values.yaml b/charts/hdfs-k8s/values.yaml
index 77ca3fe..8e313d2 100644
--- a/charts/hdfs-k8s/values.yaml
+++ b/charts/hdfs-k8s/values.yaml
@@ -170,6 +170,9 @@ hdfs-krb5-k8s:
 ## Global values affecting all sub-charts:
 ## ------------------------------------------------------------------------------
 global:
+  # Domain suffix to be used for FQDN
+  cluster_domain_suffix: cluster.local