Initial support for multi kubernetes clusters for k8s nodes

Change-Id: I6ca132898f8e157e0583de38a637fdc135f21d6f
diff --git a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeService.java b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeService.java
index 455e42c..96ce129 100644
--- a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeService.java
+++ b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeService.java
@@ -36,6 +36,14 @@
     Set<K8sNode> nodes();
 
     /**
+     * Returns kubernetes nodes associated with cluster name.
+     *
+     * @param clusterName cluster name
+     * @return set of kubernetes nodes
+     */
+    Set<K8sNode> nodes(String clusterName);
+
+    /**
      * Returns all nodes with the specified type.
      *
      * @param type node type