[VOL-3091] configurable kafka topic

Make core-topic and adapter topics configurable in voltha-helm-charts
This is required to run multiple voltha stacks in a k8s deployment.

Also, read the kv_store_data_prefix via environment variable.
https://gerrit.opencord.org/#/c/19001/

Change-Id: I8fabda3ce70f1379f735796e6711f4282e57008a
diff --git a/voltha/Chart.yaml b/voltha/Chart.yaml
index d721cf0..293aee9 100644
--- a/voltha/Chart.yaml
+++ b/voltha/Chart.yaml
@@ -14,7 +14,7 @@
 # limitations under the License.
 apiVersion: "v1"
 name: "voltha"
-version: "2.4.8"
+version: "2.4.9"
 description: "A Helm chart for Voltha based on K8S resources in Voltha project"
 keywords:
   - "onf"
diff --git a/voltha/templates/core-deploy.yaml b/voltha/templates/core-deploy.yaml
index 1a805ec..6ce8406 100644
--- a/voltha/templates/core-deploy.yaml
+++ b/voltha/templates/core-deploy.yaml
@@ -74,6 +74,8 @@
               valueFrom:
                 fieldRef:
                   fieldPath: metadata.labels['app.kubernetes.io/name']
+            - name: KV_STORE_DATAPATH_PREFIX
+              value: {{ .Values.defaults.kv_store_data_prefix }}
           args:
             - "/app/rw_core"
             - "-kv_store_type=etcd"
@@ -86,9 +88,7 @@
             - "-kafka_adapter_port={{ .Values.services.kafka.adapter.port }}"
             - "-kafka_cluster_host={{ .Values.services.kafka.cluster.service }}"
             - "-kafka_cluster_port={{ .Values.services.kafka.cluster.port }}"
-            - "-rw_core_topic=rwcore"
-            - "-core_pair_topic=core-pair-1"
-            - "-kv_store_data_prefix=service/voltha"
+            - "-rw_core_topic={{ .Values.defaults.topics.core_topic }}"
             - "-in_competing_mode=false"
             - "-core_timeout=10s"
             - "-timeout_long_request=10s"
diff --git a/voltha/values.yaml b/voltha/values.yaml
index 52b72a7..cb2b9e1 100644
--- a/voltha/values.yaml
+++ b/voltha/values.yaml
@@ -24,6 +24,13 @@
   image_pullPolicy: "Always"
   rw_core:
     timeout: "8000"
+  topics:
+    core_topic: "rwcore"
+    
+  # Define prefix path for etcd
+  # If you're running multiple voltha stacks the this value 
+  # should be unique across the stacks.
+  kv_store_data_prefix: "service/voltha"
 
 securityContext:
   enabled: true