Implement kubernetes external loadbalancer handler.

Change-Id: I0f3057d66769f0ca7db7d508483835cdd1ff1593
diff --git a/apps/kubevirt-node/api/src/main/java/org/onosproject/kubevirtnode/api/DefaultKubernetesExternalLbInterface.java b/apps/kubevirt-node/api/src/main/java/org/onosproject/kubevirtnode/api/DefaultKubernetesExternalLbInterface.java
new file mode 100644
index 0000000..fe53b53
--- /dev/null
+++ b/apps/kubevirt-node/api/src/main/java/org/onosproject/kubevirtnode/api/DefaultKubernetesExternalLbInterface.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2022-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;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.MacAddress;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+public class DefaultKubernetesExternalLbInterface implements KubernetesExternalLbInterface {
+
+    private static final String NOT_NULL_MSG = "KubernetesExternalLbInterface % cannot be null";
+
+    private String elbBridgeName;
+    private IpAddress elbIp;
+    private IpAddress elbGwIp;
+    private MacAddress elbGwMac;
+
+    public DefaultKubernetesExternalLbInterface(String elbBridgeName, IpAddress elbIp,
+                                                IpAddress elbGwIp, MacAddress elbGwMac) {
+        this.elbBridgeName = elbBridgeName;
+        this.elbIp = elbIp;
+        this.elbGwIp = elbGwIp;
+        this.elbGwMac = elbGwMac;
+    }
+
+    @Override
+    public String externalLbBridgeName() {
+        return elbBridgeName;
+    }
+
+    @Override
+    public IpAddress externalLbIp() {
+        return elbIp;
+    }
+
+    @Override
+    public IpAddress externalLbGwIp() {
+        return elbGwIp;
+    }
+
+    @Override
+    public MacAddress externalLbGwMac() {
+        return elbGwMac;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        DefaultKubernetesExternalLbInterface that = (DefaultKubernetesExternalLbInterface) o;
+
+        return Objects.equals(elbBridgeName, that.elbBridgeName) &&
+                Objects.equals(elbIp, that.elbIp) &&
+                Objects.equals(elbGwIp, that.elbGwIp);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("elbBridgeName", elbBridgeName)
+                .add("elbIp", elbIp)
+                .add("elbGwIp", elbGwIp)
+                .add("elbGwMac", elbGwMac)
+                .toString();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(elbBridgeName, elbIp, elbGwIp);
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static final class Builder implements KubernetesExternalLbInterface.Builder {
+        private String elbBridgeName;
+        private IpAddress elbIp;
+        private IpAddress elbGwIp;
+        private MacAddress elbGwMac;
+
+        private Builder() {
+        }
+
+        @Override
+        public KubernetesExternalLbInterface build() {
+            checkArgument(elbBridgeName != null, NOT_NULL_MSG, "externalLbBridgeName");
+            checkArgument(elbIp != null, NOT_NULL_MSG, "externalLbIp");
+            checkArgument(elbGwIp != null, NOT_NULL_MSG, "externalLbGwIp");
+            checkArgument(elbGwMac != null, NOT_NULL_MSG, "externalLbGwMac");
+
+            return new DefaultKubernetesExternalLbInterface(elbBridgeName, elbIp, elbGwIp, elbGwMac);
+        }
+
+        @Override
+        public Builder externalLbBridgeName(String elbBridgeName) {
+            this.elbBridgeName = elbBridgeName;
+            return this;
+        }
+
+        @Override
+        public Builder externalLbIp(IpAddress elbIp) {
+            this.elbIp = elbIp;
+            return this;
+        }
+
+        @Override
+        public Builder externallbGwIp(IpAddress elbGwIp) {
+            this.elbGwIp = elbGwIp;
+            return this;
+        }
+
+        @Override
+        public Builder externalLbGwMac(MacAddress elbGwMac) {
+            this.elbGwMac = elbGwMac;
+            return this;
+        }
+    }
+}