[ONOS-7905] Add a set of interfaces for k8s-networking data model

Change-Id: I18b2e718705999da61f26e1c482942d424c7c1c0
diff --git a/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sNetworkEvent.java b/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sNetworkEvent.java
new file mode 100644
index 0000000..ea097bc
--- /dev/null
+++ b/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sNetworkEvent.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2019-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.k8snetworking.api;
+
+import org.onosproject.event.AbstractEvent;
+
+/**
+ * Describes kubernetes network service event.
+ */
+public class K8sNetworkEvent extends AbstractEvent<K8sNetworkEvent.Type, K8sNetwork> {
+
+    /**
+     * Creates an event of a given type for the specified network.
+     *
+     * @param type kubernetes network event type
+     * @param subject kubernetes network
+     */
+    protected K8sNetworkEvent(Type type, K8sNetwork subject) {
+        super(type, subject);
+    }
+
+    /**
+     * Kubernetes network events.
+     */
+    public enum Type {
+
+        /**
+         * Signifies that a new kubernetes network is created.
+         */
+        K8S_NETWORK_CREATED,
+
+        /**
+         * Signifies that the kubernetes network is updated.
+         */
+        K8S_NETWORK_UPDATED,
+
+        /**
+         * Signifies that the kubernetes network is removed.
+         */
+        K8S_NETWORK_REMOVED,
+    }
+}