Initial implementation of kubevirt node along with test cases

Change-Id: I02f6abf2ae58dd79367a8b0b7e4a36fa966bf573
diff --git a/apps/kubevirt-node/api/src/main/java/org/onosproject/kubevirtnode/api/Constants.java b/apps/kubevirt-node/api/src/main/java/org/onosproject/kubevirtnode/api/Constants.java
new file mode 100644
index 0000000..c04c183
--- /dev/null
+++ b/apps/kubevirt-node/api/src/main/java/org/onosproject/kubevirtnode/api/Constants.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2020-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.kubevirtnode.api;
+
+/**
+ * Provides constants used in KubeVirt node services.
+ */
+public final class Constants {
+
+    private Constants() {
+    }
+
+    public static final String VXLAN = "vxlan";
+    public static final String GRE = "gre";
+    public static final String GENEVE = "geneve";
+
+    public static final String DEFAULT_CLUSTER_NAME = "default";
+}