Implement kubevirt floating IP's class, codec, watcher and APIs

Change-Id: I2111902e86083add8a00af62557fac1e98b7e7fc
(cherry picked from commit e48a617ccaf19d0d29ccc3211f6254be5e26826e)
diff --git a/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/codec/KubevirtFloatingIpCodec.java b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/codec/KubevirtFloatingIpCodec.java
new file mode 100644
index 0000000..16fd082
--- /dev/null
+++ b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/codec/KubevirtFloatingIpCodec.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2021-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.kubevirtnetworking.codec;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onlab.packet.IpAddress;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.kubevirtnetworking.api.DefaultKubevirtFloatingIp;
+import org.onosproject.kubevirtnetworking.api.KubevirtFloatingIp;
+import org.slf4j.Logger;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.util.Tools.nullIsIllegal;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Kubevirt floating IP codec used for serializing and de-serializing JSON string.
+ */
+public final class KubevirtFloatingIpCodec extends JsonCodec<KubevirtFloatingIp> {
+
+    private final Logger log = getLogger(getClass());
+
+    private static final String ID = "id";
+    private static final String ROUTER_NAME = "routerName";
+    private static final String POD_NAME = "podName";
+    private static final String FLOATING_IP = "floatingIp";
+    private static final String FIXED_IP = "fixedIp";
+
+    private static final String MISSING_MESSAGE = " is required in KubevirtFloatingIp";
+
+    @Override
+    public ObjectNode encode(KubevirtFloatingIp fip, CodecContext context) {
+        checkNotNull(fip, "Kubevirt floating IP cannot be null");
+
+        ObjectNode result = context.mapper().createObjectNode()
+                .put(ID, fip.id())
+                .put(ROUTER_NAME, fip.routerName())
+                .put(FLOATING_IP, fip.floatingIp().toString());
+
+        if (fip.podName() != null) {
+            result.put(POD_NAME, fip.podName());
+        }
+
+        if (fip.fixedIp() != null) {
+            result.put(FIXED_IP, fip.fixedIp().toString());
+        }
+
+        return result;
+    }
+
+    @Override
+    public KubevirtFloatingIp decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        String id = nullIsIllegal(json.get(ID).asText(), ID + MISSING_MESSAGE);
+        String routerName = nullIsIllegal(json.get(ROUTER_NAME).asText(),
+                ROUTER_NAME + MISSING_MESSAGE);
+        String floatingIp = nullIsIllegal(json.get(FLOATING_IP).asText(),
+                FLOATING_IP + MISSING_MESSAGE);
+
+        KubevirtFloatingIp.Builder builder = DefaultKubevirtFloatingIp.builder()
+                .id(id)
+                .routerName(routerName)
+                .floatingIp(IpAddress.valueOf(floatingIp));
+
+        JsonNode podName = json.get(POD_NAME);
+        if (podName != null) {
+            builder.podName(podName.asText());
+        }
+
+        JsonNode fixedIp = json.get(FIXED_IP);
+        if (fixedIp != null) {
+            builder.fixedIp(IpAddress.valueOf(fixedIp.asText()));
+        }
+
+        return builder.build();
+    }
+}