Initial commit to implement external loadbalancer for kubernetes pods.
  - Adds elb-related parameters in KubevirtNode class
  - Defines KubernetesExternalLb and related service, manager and store.

Change-Id: I68476887af493c7daeaf1dca0320218f1764653f
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/DefaultKubernetesExternalLb.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/DefaultKubernetesExternalLb.java
new file mode 100644
index 0000000..96ecf12
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/DefaultKubernetesExternalLb.java
@@ -0,0 +1,187 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableSet;
+
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Default implementation of kubernetes external load balancer.
+ */
+public final class DefaultKubernetesExternalLb implements KubernetesExternalLb {
+
+    private static final String NOT_NULL_MSG = "Loadbalancer % cannot be null";
+
+    private final String serviceName;
+    private final String loadbalancerIp;
+    private final Set<Integer> nodePortSet;
+    private final Set<Integer> portSet;
+    private final Set<String> endpointSet;
+    private final String electedGateway;
+
+    public DefaultKubernetesExternalLb(String serviceName, String loadbalancerIp,
+                                       Set<Integer> nodePortSet, Set<Integer> portSet,
+                                       Set<String> endpointSet, String electedGateway) {
+        this.serviceName = serviceName;
+        this.loadbalancerIp = loadbalancerIp;
+        this.nodePortSet = nodePortSet;
+        this.portSet = portSet;
+        this.endpointSet = endpointSet;
+        this.electedGateway = electedGateway;
+    }
+
+    @Override
+    public String serviceName() {
+        return serviceName;
+    }
+
+    @Override
+    public String loadBalancerIp() {
+        return loadbalancerIp;
+    }
+
+    @Override
+    public Set<Integer> nodePortSet() {
+        return ImmutableSet.copyOf(nodePortSet);
+    }
+
+    @Override
+    public Set<Integer> portSet() {
+        return ImmutableSet.copyOf(portSet);
+    }
+
+    @Override
+    public Set<String> endpointSet() {
+        return ImmutableSet.copyOf(endpointSet);
+    }
+
+    @Override
+    public String electedGateway() {
+        return electedGateway;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        DefaultKubernetesExternalLb that = (DefaultKubernetesExternalLb) o;
+        return serviceName.equals(that.serviceName) && loadbalancerIp.equals(that.loadbalancerIp) &&
+                Objects.equals(nodePortSet, that.nodePortSet) &&
+                Objects.equals(portSet, that.portSet) &&
+                Objects.equals(endpointSet, that.endpointSet) &&
+                Objects.equals(electedGateway, that.electedGateway);
+    }
+
+    @Override
+    public KubernetesExternalLb updateElectedGateway(String electedGateway) {
+        return DefaultKubernetesExternalLb.builder()
+                .serviceName(serviceName)
+                .loadBalancerIp(loadbalancerIp)
+                .nodePortSet(nodePortSet)
+                .portSet(portSet)
+                .endpointSet(endpointSet)
+                .electedGateway(electedGateway)
+                .build();
+    }
+    @Override
+    public int hashCode() {
+        return Objects.hash(serviceName, loadbalancerIp);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("serviceName", serviceName)
+                .add("loadbalancerIp", loadbalancerIp)
+                .add("nodePort", nodePortSet)
+                .add("port", portSet)
+                .add("endpointSet", endpointSet)
+                .add("electedGateway", electedGateway)
+                .toString();
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static final class Builder implements KubernetesExternalLb.Builder {
+        private String serviceName;
+        private String loadbalancerIp;
+        private Set<Integer> nodePortSet;
+        private Set<Integer> portSet;
+        private Set<String> endpointSet;
+        private String electedGateway;
+
+        private Builder() {
+        }
+
+        @Override
+        public KubernetesExternalLb build() {
+            checkArgument(serviceName != null, NOT_NULL_MSG, "serviceName");
+            checkArgument(loadbalancerIp != null, NOT_NULL_MSG, "loadbalancerIp");
+            checkArgument(!nodePortSet.isEmpty(), NOT_NULL_MSG, "nodePortSet");
+            checkArgument(!portSet.isEmpty(), NOT_NULL_MSG, "portSet");
+
+            return new DefaultKubernetesExternalLb(serviceName, loadbalancerIp,
+                    nodePortSet, portSet, endpointSet, electedGateway);
+        }
+
+        @Override
+        public Builder serviceName(String serviceName) {
+            this.serviceName = serviceName;
+            return this;
+        }
+
+        @Override
+        public Builder loadBalancerIp(String loadBalancerIp) {
+            this.loadbalancerIp = loadBalancerIp;
+            return this;
+        }
+
+        @Override
+        public Builder nodePortSet(Set<Integer> nodePortSet) {
+            this.nodePortSet = nodePortSet;
+            return this;
+        }
+
+        @Override
+        public Builder portSet(Set<Integer> portSet) {
+            this.portSet = portSet;
+            return this;
+        }
+
+        @Override
+        public Builder endpointSet(Set<String> endpointSet) {
+            this.endpointSet = endpointSet;
+            return this;
+        }
+
+        public Builder electedGateway(String electedGateway) {
+            this.electedGateway = electedGateway;
+            return this;
+        }
+    }
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLb.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLb.java
new file mode 100644
index 0000000..bc754db
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLb.java
@@ -0,0 +1,130 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import java.util.Set;
+
+/**
+ * Representation of kubernetes external load balancer.
+ */
+public interface KubernetesExternalLb {
+    /**
+     * Returns the service name.
+     *
+     * @return service name
+     */
+    String serviceName();
+
+    /**
+     * Returns the load balancer IP.
+     *
+     * @return load balancer IP
+     */
+    String loadBalancerIp();
+
+    /**
+     * Returns the set of node port.
+     *
+     * @return node port
+     */
+    Set<Integer> nodePortSet();
+
+    /**
+     * Returns the set of port.
+     *
+     * @return port number
+     */
+    Set<Integer> portSet();
+
+    /**
+     * Returns the set of endpoint.
+     *
+     * @return endpoint set
+     */
+    Set<String> endpointSet();
+
+    /**
+     * Returns the elected gateway node for this service.
+     *
+     * @return gateway node hostname
+     */
+    String electedGateway();
+
+    /**
+     * Updates the elected gateway node host name.
+     *
+     * @param electedGateway updated elected gateway node hostname
+     * @return kubernetes external lb with the updated gateway node hostname
+     */
+    KubernetesExternalLb updateElectedGateway(String electedGateway);
+
+    interface Builder {
+        /**
+         * Builds an immutable kubernetes external load balancer instance.
+         *
+         * @return kubernetes external load balancer
+         */
+        KubernetesExternalLb build();
+
+        /**
+         * Returns kubernetes external load balancer builder with supplied service name.
+         *
+         * @param serviceName external load balancer service name
+         * @return external load balancer builder
+         */
+        Builder serviceName(String serviceName);
+
+        /**
+         * Returns kubernetes external load balancer builder with supplied load balancer Ip.
+         *
+         * @param loadBalancerIp external load balancer Ip
+         * @return external load balancer builder
+         */
+        Builder loadBalancerIp(String loadBalancerIp);
+
+        /**
+         * Returns kubernetes external load balancer builder with supplied node port set.
+         *
+         * @param nodePortSet node port set
+         * @return external load balancer builder
+         */
+        Builder nodePortSet(Set<Integer> nodePortSet);
+
+        /**
+         * Returns kubernetes external load balancer builder with supplied port set.
+         *
+         * @param portSet port set
+         * @return external load balancer builder
+         */
+        Builder portSet(Set<Integer> portSet);
+
+        /**
+         * Returns kubernetes external load balancer builder with supplied endpoint set.
+         *
+         * @param endpointSet endpoint set
+         * @return external load balancer builder
+         */
+        Builder endpointSet(Set<String> endpointSet);
+
+        /**
+         * Returns kubernetes external load balancer builder with supplied elected gateway.
+         *
+         * @param gateway gateway node hostname
+         * @return gateway node hostname
+         */
+        Builder electedGateway(String gateway);
+    }
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbAdminService.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbAdminService.java
new file mode 100644
index 0000000..c53d409
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbAdminService.java
@@ -0,0 +1,47 @@
+/*
+ * 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.api;
+
+/**
+ * Service for administering the inventory of kubernetes external lb service.
+ */
+public interface KubernetesExternalLbAdminService extends KubernetesExternalLbService {
+    /**
+     * Create a kubernetes external load balancer with the given information.
+     *
+     * @param externalLb a new load balancer
+     */
+    void createExternalLb(KubernetesExternalLb externalLb);
+
+    /**
+     * Update a kubernetes external load balancer with the given information.
+     *
+     * @param externalLb the updated load balancer
+     */
+    void updateExternalLb(KubernetesExternalLb externalLb);
+
+    /**
+     * Removes the load balancer.
+     *
+     * @param serviceName load balancer name
+     */
+    void removeExternalLb(String serviceName);
+
+    /**
+     * Removes all load balancers.
+     */
+    void clear();
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbEvent.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbEvent.java
new file mode 100644
index 0000000..15f3905
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbEvent.java
@@ -0,0 +1,49 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import org.onosproject.event.AbstractEvent;
+
+/**
+ * Manages inventory of kubernetes external load balancer states; not intended for direct use.
+ */
+public class KubernetesExternalLbEvent
+    extends AbstractEvent<KubernetesExternalLbEvent.Type, KubernetesExternalLb> {
+
+    public KubernetesExternalLbEvent(Type type, KubernetesExternalLb subject) {
+        super(type, subject);
+    }
+
+    /**
+     * Kubernetes external lb events.
+     */
+    public enum Type {
+        /**
+         * Signifies that a new kubevirt load balancer is created.
+         */
+        KUBERNETES_EXTERNAL_LOAD_BALANCER_CREATED,
+
+        /**
+         * Signifies that a kubevirt load balancer is removed.
+         */
+        KUBERNETES_EXTERNAL_LOAD_BALANCER_REMOVED,
+
+        /**
+         * Signifies that a kubevirt load balancer is updated.
+         */
+        KUBERNETES_EXTERNAL_LOAD_BALANCER_UPDATED,
+    }
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbListener.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbListener.java
new file mode 100644
index 0000000..1a48764
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbListener.java
@@ -0,0 +1,24 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import org.onosproject.event.EventListener;
+
+/**
+ * Listener for kubernetes external lb event.
+ */
+public interface KubernetesExternalLbListener extends EventListener<KubernetesExternalLbEvent> {
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbService.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbService.java
new file mode 100644
index 0000000..eeac4f2
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbService.java
@@ -0,0 +1,39 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import org.onosproject.event.ListenerService;
+
+import java.util.Set;
+
+public interface KubernetesExternalLbService
+    extends ListenerService<KubernetesExternalLbEvent, KubernetesExternalLbListener> {
+
+    /**
+     * Returns the kubernetes external lb with the supplied service name.
+     *
+     * @param serviceName service name
+     * @return kubernetes external load balancer
+     */
+    KubernetesExternalLb loadBalancer(String serviceName);
+
+    /**
+     * Returns all kubernetes external lb's registered in the service.
+     *
+     * @return set of kubernetes external lb's
+     */
+    Set<KubernetesExternalLb> loadBalancers();
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbStore.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbStore.java
new file mode 100644
index 0000000..996cbf0
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbStore.java
@@ -0,0 +1,69 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import org.onosproject.store.Store;
+
+import java.util.Set;
+
+/**
+ * Manages inventory of kubernetes external load balancer states; not intended for direct use.
+ */
+public interface KubernetesExternalLbStore
+        extends Store<KubernetesExternalLbEvent, KubernetesExternalLbStoreDelegate> {
+
+    /**
+     * Creates a new kubernetes external lb.
+     *
+     * @param lb kubernetes external lb
+     */
+    void createLoadBalancer(KubernetesExternalLb lb);
+
+    /**
+     * Updates a new kubernetes external lb.
+     *
+     * @param lb kubernetes external lb
+     */
+    void updateLoadBalancer(KubernetesExternalLb lb);
+
+    /**
+     * Removes the kubernetes external lb with the given lb name.
+     *
+     * @param serviceName service name
+     * @return kubernetes external lb
+     */
+    KubernetesExternalLb removeLoadBalancer(String serviceName);
+
+    /**
+     * Returns the kubernetes external lb with the given lb name.
+     *
+     * @param serviceName service name
+     * @return kubernetes external lb
+     */
+    KubernetesExternalLb loadBalancer(String serviceName);
+
+    /**
+     * Returns all kubernetes external lbs.
+     *
+     * @return set of kubernetes external lbs
+     */
+    Set<KubernetesExternalLb> loadBalancers();
+
+    /**
+     * Removes all kubernetes external lbs.
+     */
+    void clear();
+}
diff --git a/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbStoreDelegate.java b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbStoreDelegate.java
new file mode 100644
index 0000000..a7fba41
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/main/java/org/onosproject/kubevirtnetworking/api/KubernetesExternalLbStoreDelegate.java
@@ -0,0 +1,24 @@
+/*
+ * 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.kubevirtnetworking.api;
+
+import org.onosproject.store.StoreDelegate;
+
+/**
+ * Kubernetes external lb store delegate abstraction.
+ */
+public interface KubernetesExternalLbStoreDelegate extends StoreDelegate<KubernetesExternalLbEvent> {
+}
diff --git a/apps/kubevirt-networking/api/src/test/java/org/onosproject/kubevirtnetworking/api/DefaultKubernetesExternalLbTest.java b/apps/kubevirt-networking/api/src/test/java/org/onosproject/kubevirtnetworking/api/DefaultKubernetesExternalLbTest.java
new file mode 100644
index 0000000..a4a661f
--- /dev/null
+++ b/apps/kubevirt-networking/api/src/test/java/org/onosproject/kubevirtnetworking/api/DefaultKubernetesExternalLbTest.java
@@ -0,0 +1,113 @@
+/*
+ * 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.api;
+
+import com.google.common.collect.Sets;
+import com.google.common.testing.EqualsTester;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Set;
+
+import static junit.framework.TestCase.assertEquals;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+/**
+ * Unit tests for the default Kubernetes external lb class.
+ */
+public class DefaultKubernetesExternalLbTest {
+    private static final String SERVICE_NAME_1 = "service_name_1";
+    private static final String SERVICE_NAME_2 = "service_name_2";
+    private static final String LOADBALANCER_IP_1 = "1.1.1.1";
+    private static final String LOADBALANCER_IP_2 = "2.2.2.2";
+    private static final Set<Integer> NODE_PORT_SET_1 = Sets.newHashSet(Integer.valueOf(32080));
+    private static final Set<Integer> NODE_PORT_SET_2 = Sets.newHashSet(Integer.valueOf(33080));
+    private static final Set<Integer> PORT_SET_1 = Sets.newHashSet(Integer.valueOf(8080));
+    private static final Set<Integer> PORT_SET_2 = Sets.newHashSet(Integer.valueOf(9090));
+    private static final Set<String> ENDPOINT_SET_1 = Sets.newHashSet(String.valueOf("1.1.2.1"));
+    private static final Set<String> ENDPOINT_SET_2 = Sets.newHashSet(String.valueOf("1.1.2.2"));
+    private static final String ELECTED_GATEWAY_1 = "gateway1";
+    private static final String ELECTED_GATEWAY_2 = "gateway2";
+
+    private KubernetesExternalLb lb1;
+    private KubernetesExternalLb sameAsLb1;
+    private KubernetesExternalLb lb2;
+
+    /**
+     * Tests class immutability.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(DefaultKubernetesExternalLb.class);
+    }
+
+    /**
+     * Initial setup for this unit test.
+     */
+    @Before
+    public void setUp() {
+        lb1 = DefaultKubernetesExternalLb.builder()
+                .serviceName(SERVICE_NAME_1)
+                .loadBalancerIp(LOADBALANCER_IP_1)
+                .nodePortSet(NODE_PORT_SET_1)
+                .portSet(PORT_SET_1)
+                .endpointSet(ENDPOINT_SET_1)
+                .electedGateway(ELECTED_GATEWAY_1)
+                .build();
+
+        sameAsLb1 = DefaultKubernetesExternalLb.builder()
+                .serviceName(SERVICE_NAME_1)
+                .loadBalancerIp(LOADBALANCER_IP_1)
+                .nodePortSet(NODE_PORT_SET_1)
+                .portSet(PORT_SET_1)
+                .endpointSet(ENDPOINT_SET_1)
+                .electedGateway(ELECTED_GATEWAY_1)
+                .build();
+
+        lb2 = DefaultKubernetesExternalLb.builder()
+                .serviceName(SERVICE_NAME_2)
+                .loadBalancerIp(LOADBALANCER_IP_2)
+                .nodePortSet(NODE_PORT_SET_2)
+                .portSet(PORT_SET_2)
+                .endpointSet(ENDPOINT_SET_2)
+                .electedGateway(ELECTED_GATEWAY_2)
+                .build();
+    }
+
+    /**
+     * Tests object equality.
+     */
+    @Test
+    public void testEquality() {
+        new EqualsTester().addEqualityGroup(lb1, sameAsLb1)
+                .addEqualityGroup(lb2)
+                .testEquals();
+    }
+
+    /**
+     * Test object construction.
+     */
+    @Test
+    public void testConstruction() {
+        KubernetesExternalLb lb = lb1;
+
+        assertEquals(SERVICE_NAME_1, lb1.serviceName());
+        assertEquals(LOADBALANCER_IP_1, lb1.loadBalancerIp());
+        assertEquals(NODE_PORT_SET_1, lb1.nodePortSet());
+        assertEquals(PORT_SET_1, lb1.portSet());
+        assertEquals(ENDPOINT_SET_1, lb1.endpointSet());
+    }
+}
diff --git a/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/impl/DistributedKubernetesExternalLbStore.java b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/impl/DistributedKubernetesExternalLbStore.java
new file mode 100644
index 0000000..fce69d7
--- /dev/null
+++ b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/impl/DistributedKubernetesExternalLbStore.java
@@ -0,0 +1,179 @@
+/*
+ * 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.kubevirtnetworking.impl;
+
+import com.google.common.collect.ImmutableSet;
+import org.onlab.util.KryoNamespace;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.kubevirtnetworking.api.DefaultKubernetesExternalLb;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLb;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbEvent;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbStore;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbStoreDelegate;
+import org.onosproject.store.AbstractStore;
+import org.onosproject.store.serializers.KryoNamespaces;
+import org.onosproject.store.service.ConsistentMap;
+import org.onosproject.store.service.MapEvent;
+import org.onosproject.store.service.MapEventListener;
+import org.onosproject.store.service.Serializer;
+import org.onosproject.store.service.StorageService;
+import org.onosproject.store.service.Versioned;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Deactivate;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
+import org.slf4j.Logger;
+
+import java.util.Collection;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+import static org.onlab.util.Tools.groupedThreads;
+import static org.onosproject.kubevirtnetworking.api.KubernetesExternalLbEvent.Type.KUBERNETES_EXTERNAL_LOAD_BALANCER_CREATED;
+import static org.onosproject.kubevirtnetworking.api.KubernetesExternalLbEvent.Type.KUBERNETES_EXTERNAL_LOAD_BALANCER_REMOVED;
+import static org.onosproject.kubevirtnetworking.api.KubernetesExternalLbEvent.Type.KUBERNETES_EXTERNAL_LOAD_BALANCER_UPDATED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Implementation of kubernetes external lb store using consistent map.
+ */
+@Component(immediate = true, service = KubernetesExternalLbStore.class)
+public class DistributedKubernetesExternalLbStore
+    extends AbstractStore<KubernetesExternalLbEvent, KubernetesExternalLbStoreDelegate>
+    implements KubernetesExternalLbStore {
+
+    private final Logger log = getLogger(getClass());
+
+    private static final String ERR_NOT_FOUND = " does not exist";
+    private static final String ERR_DUPLICATE = " already exists";
+    private static final String APP_ID = "org.onosproject.kubevirtnetwork";
+
+    private static final KryoNamespace SERIALIZER_KUBERNETES_EXTERNAL_LB = KryoNamespace.newBuilder()
+            .register(KryoNamespaces.API)
+            .register(KubernetesExternalLb.class)
+            .register(DefaultKubernetesExternalLb.class)
+            .register(Collection.class)
+            .build();
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected StorageService storageService;
+
+    private final ExecutorService eventExecutor = newSingleThreadExecutor(
+            groupedThreads(this.getClass().getSimpleName(), "event-handler", log));
+
+    private final MapEventListener<String, KubernetesExternalLb> lbMapEventListener =
+            new KubernetesExternalLbMapListener();
+
+    private ConsistentMap<String, KubernetesExternalLb> lbStore;
+
+    @Activate
+    protected void activate() {
+        ApplicationId appId = coreService.registerApplication(APP_ID);
+        lbStore = storageService.<String, KubernetesExternalLb>consistentMapBuilder()
+                .withSerializer(Serializer.using(SERIALIZER_KUBERNETES_EXTERNAL_LB))
+                .withName("kubernetes-lbstore")
+                .withApplicationId(appId)
+                .build();
+
+        lbStore.addListener(lbMapEventListener);
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        lbStore.removeListener(lbMapEventListener);
+        eventExecutor.shutdown();
+        log.info("Stopped");
+    }
+
+    @Override
+    public void createLoadBalancer(KubernetesExternalLb lb) {
+        lbStore.compute(lb.serviceName(), (seviceName, existing) -> {
+            final String error = lb.serviceName() + ERR_DUPLICATE;
+            checkArgument(existing == null, error);
+            return lb;
+        });
+    }
+
+    @Override
+    public void updateLoadBalancer(KubernetesExternalLb lb) {
+        lbStore.compute(lb.serviceName(), (seviceName, existing) -> {
+            final String error = lb.serviceName() + ERR_NOT_FOUND;
+            checkArgument(existing != null, error);
+            return lb;
+        });
+    }
+
+    @Override
+    public KubernetesExternalLb removeLoadBalancer(String serviceName) {
+
+        Versioned<KubernetesExternalLb> lb = lbStore.remove(serviceName);
+
+        if (lb == null) {
+            final String error = serviceName + ERR_NOT_FOUND;
+            throw new IllegalArgumentException(error);
+        }
+        return lb.value();
+    }
+
+    @Override
+    public KubernetesExternalLb loadBalancer(String serviceName) {
+        return lbStore.asJavaMap().get(serviceName);
+    }
+
+    @Override
+    public Set<KubernetesExternalLb> loadBalancers() {
+        return  ImmutableSet.copyOf(lbStore.asJavaMap().values());
+    }
+
+    @Override
+    public void clear() {
+        lbStore.clear();
+    }
+
+    private class KubernetesExternalLbMapListener implements MapEventListener<String, KubernetesExternalLb> {
+        @Override
+        public void event(MapEvent<String, KubernetesExternalLb> event) {
+            switch (event.type()) {
+                case INSERT:
+                    eventExecutor.execute(() ->
+                            notifyDelegate(new KubernetesExternalLbEvent(
+                                    KUBERNETES_EXTERNAL_LOAD_BALANCER_CREATED, event.newValue().value())));
+                    break;
+                case UPDATE:
+                    eventExecutor.execute(() ->
+                            notifyDelegate(new KubernetesExternalLbEvent(
+                                    KUBERNETES_EXTERNAL_LOAD_BALANCER_UPDATED, event.newValue().value())));
+                    break;
+                case REMOVE:
+                    eventExecutor.execute(() ->
+                            notifyDelegate(new KubernetesExternalLbEvent(
+                                    KUBERNETES_EXTERNAL_LOAD_BALANCER_REMOVED, event.newValue().value())));
+                    break;
+                default:
+                    //do nothing
+                    break;
+            }
+        }
+    }
+}
diff --git a/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/impl/KubernetesExternalLbManager.java b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/impl/KubernetesExternalLbManager.java
new file mode 100644
index 0000000..e68d289
--- /dev/null
+++ b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/impl/KubernetesExternalLbManager.java
@@ -0,0 +1,150 @@
+/*
+ * 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.kubevirtnetworking.impl;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableSet;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.event.ListenerRegistry;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLb;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbAdminService;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbEvent;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbListener;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbService;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbStore;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLbStoreDelegate;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Deactivate;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
+import org.slf4j.Logger;
+
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onosproject.kubevirtnetworking.api.Constants.KUBEVIRT_NETWORKING_APP_ID;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Provides implementation of administrating and interfacing kubernetes external lb.
+ */
+@Component(
+        immediate = true,
+        service = {KubernetesExternalLbAdminService.class, KubernetesExternalLbService.class}
+)
+public class KubernetesExternalLbManager
+        extends ListenerRegistry<KubernetesExternalLbEvent, KubernetesExternalLbListener>
+        implements KubernetesExternalLbAdminService, KubernetesExternalLbService {
+
+    protected final Logger log = getLogger(getClass());
+
+    private static final String MSG_LOAD_BALANCER = "Kubernetes external lb %s %s";
+    private static final String MSG_CREATED = "created";
+    private static final String MSG_UPDATED = "updated";
+    private static final String MSG_REMOVED = "removed";
+
+    private static final String ERR_NULL_LOAD_BALANCER = "Kubernetes external lb cannot be null";
+    private static final String ERR_NULL_LOAD_BALANCER_NAME = "Kubernetes external lb name cannot be null";
+    private static final String ERR_IN_USE = " still in use";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected KubernetesExternalLbStore lbStore;
+
+    private final InternalKubernetesExternalLbStorageDelegate delegate =
+            new InternalKubernetesExternalLbStorageDelegate();
+
+    private ApplicationId appId;
+
+    @Activate
+    protected void activate() {
+        appId = coreService.registerApplication(KUBEVIRT_NETWORKING_APP_ID);
+
+        lbStore.setDelegate(delegate);
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        lbStore.unsetDelegate(delegate);
+        log.info("Stopped");
+    }
+
+    @Override
+    public void createExternalLb(KubernetesExternalLb externalLb) {
+        checkNotNull(externalLb, ERR_NULL_LOAD_BALANCER);
+        checkArgument(!Strings.isNullOrEmpty(externalLb.serviceName()), ERR_NULL_LOAD_BALANCER_NAME);
+
+
+        lbStore.createLoadBalancer(externalLb);
+        log.info(String.format(MSG_LOAD_BALANCER, externalLb.serviceName(), MSG_CREATED));
+
+    }
+
+    @Override
+    public void updateExternalLb(KubernetesExternalLb externalLb) {
+        checkNotNull(externalLb, ERR_NULL_LOAD_BALANCER);
+        checkArgument(!Strings.isNullOrEmpty(externalLb.serviceName()), ERR_NULL_LOAD_BALANCER_NAME);
+
+        lbStore.updateLoadBalancer(externalLb);
+        log.info(String.format(MSG_LOAD_BALANCER, externalLb.serviceName(), MSG_UPDATED));
+    }
+
+    @Override
+    public void removeExternalLb(String serviceName) {
+        checkArgument(serviceName != null, ERR_NULL_LOAD_BALANCER_NAME);
+
+        synchronized (this) {
+            KubernetesExternalLb externalLb = lbStore.removeLoadBalancer(serviceName);
+
+            if (externalLb != null) {
+                log.info(String.format(MSG_LOAD_BALANCER, externalLb.serviceName(), MSG_REMOVED));
+            }
+        }
+    }
+
+    @Override
+    public void clear() {
+        lbStore.clear();
+    }
+
+    @Override
+    public KubernetesExternalLb loadBalancer(String serviceName) {
+        checkArgument(!Strings.isNullOrEmpty(serviceName), ERR_NULL_LOAD_BALANCER_NAME);
+
+        return lbStore.loadBalancer(serviceName);
+    }
+
+    @Override
+    public Set<KubernetesExternalLb> loadBalancers() {
+        return ImmutableSet.copyOf(lbStore.loadBalancers());
+    }
+
+    private class InternalKubernetesExternalLbStorageDelegate
+            implements KubernetesExternalLbStoreDelegate {
+
+        @Override
+        public void notify(KubernetesExternalLbEvent event) {
+            log.trace("send kubernetes external lb event {}", event);
+            process(event);
+        }
+    }
+}
diff --git a/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/util/KubevirtNetworkingUtil.java b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/util/KubevirtNetworkingUtil.java
index de71f29..3496008 100644
--- a/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/util/KubevirtNetworkingUtil.java
+++ b/apps/kubevirt-networking/app/src/main/java/org/onosproject/kubevirtnetworking/util/KubevirtNetworkingUtil.java
@@ -41,6 +41,7 @@
 import org.onosproject.cfg.ConfigProperty;
 import org.onosproject.kubevirtnetworking.api.DefaultKubevirtNetwork;
 import org.onosproject.kubevirtnetworking.api.DefaultKubevirtPort;
+import org.onosproject.kubevirtnetworking.api.KubernetesExternalLb;
 import org.onosproject.kubevirtnetworking.api.KubevirtHostRoute;
 import org.onosproject.kubevirtnetworking.api.KubevirtIpPool;
 import org.onosproject.kubevirtnetworking.api.KubevirtLoadBalancer;
@@ -542,6 +543,28 @@
     }
 
     /**
+     * Returns the gateway node for the specified kubernetes external lb.
+     * Among gateways, only one gateway would act as a gateway per external lb.
+     * Currently gateway node is selected based on modulo operation with router hashcode.
+     *
+     * @param nodeService kubevirt node service
+     * @param externalLb kubernetes external lb
+     * @return elected gateway node
+     */
+    public static KubevirtNode gatewayNodeForSpecifiedService(KubevirtNodeService nodeService,
+                                                              KubernetesExternalLb externalLb) {
+        //TODO: enhance election logic for a better load balancing
+
+        int numOfGateways = nodeService.completeNodes(GATEWAY).size();
+        if (numOfGateways == 0) {
+            return null;
+        }
+
+        return (KubevirtNode) nodeService.completeNodes(GATEWAY)
+                .toArray()[externalLb.hashCode() % numOfGateways];
+    }
+
+    /**
      * Returns the mac address of the router.
      *
      * @param router kubevirt router