[ONOS-7902] Add default implementation of k8s node with unit tests

Change-Id: I283967ae14dc7f38e749d7407e4bec698536c18b
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/codec/K8sNodeCodec.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/codec/K8sNodeCodec.java
new file mode 100644
index 0000000..e07ad6c
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/codec/K8sNodeCodec.java
@@ -0,0 +1,102 @@
+/*
+ * 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.k8snode.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.k8snode.api.DefaultK8sNode;
+import org.onosproject.k8snode.api.K8sNode;
+import org.onosproject.k8snode.api.K8sNodeState;
+import org.onosproject.net.DeviceId;
+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;
+
+/**
+ * Kubernetes node codec used for serializing and de-serializing JSON string.
+ */
+public final class K8sNodeCodec extends JsonCodec<K8sNode> {
+
+    private final Logger log = getLogger(getClass());
+
+    private static final String HOSTNAME = "hostname";
+    private static final String TYPE = "type";
+    private static final String MANAGEMENT_IP = "managementIp";
+    private static final String DATA_IP = "dataIp";
+    private static final String INTEGRATION_BRIDGE = "integrationBridge";
+    private static final String STATE = "state";
+
+    private static final String MISSING_MESSAGE = " is required in K8sNode";
+
+    @Override
+    public ObjectNode encode(K8sNode node, CodecContext context) {
+        checkNotNull(node, "Kubernetes node cannot be null");
+
+        ObjectNode result = context.mapper().createObjectNode()
+                .put(HOSTNAME, node.hostname())
+                .put(TYPE, node.type().name())
+                .put(STATE, node.state().name())
+                .put(MANAGEMENT_IP, node.managementIp().toString());
+
+        if (node.intgBridge() != null) {
+            result.put(INTEGRATION_BRIDGE, node.intgBridge().toString());
+        }
+
+        if (node.dataIp() != null) {
+            result.put(DATA_IP, node.dataIp().toString());
+        }
+
+        return result;
+    }
+
+    @Override
+    public K8sNode decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        String hostname = nullIsIllegal(json.get(HOSTNAME).asText(),
+                HOSTNAME + MISSING_MESSAGE);
+        String type = nullIsIllegal(json.get(TYPE).asText(),
+                TYPE + MISSING_MESSAGE);
+        String mIp = nullIsIllegal(json.get(MANAGEMENT_IP).asText(),
+                MANAGEMENT_IP + MISSING_MESSAGE);
+
+        DefaultK8sNode.Builder nodeBuilder = DefaultK8sNode.builder()
+                .hostname(hostname)
+                .type(K8sNode.Type.valueOf(type))
+                .state(K8sNodeState.INIT)
+                .managementIp(IpAddress.valueOf(mIp));
+
+        if (json.get(DATA_IP) != null) {
+            nodeBuilder.dataIp(IpAddress.valueOf(json.get(DATA_IP).asText()));
+        }
+
+        JsonNode intBridgeJson = json.get(INTEGRATION_BRIDGE);
+        if (intBridgeJson != null) {
+            nodeBuilder.intgBridge(DeviceId.deviceId(intBridgeJson.asText()));
+        }
+
+        log.trace("node is {}", nodeBuilder.build().toString());
+
+        return nodeBuilder.build();
+    }
+}
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/DistributedK8sNodeStore.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/DistributedK8sNodeStore.java
new file mode 100644
index 0000000..15d2697
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/DistributedK8sNodeStore.java
@@ -0,0 +1,201 @@
+/*
+ * 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.k8snode.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.k8snode.api.DefaultK8sNode;
+import org.onosproject.k8snode.api.K8sNode;
+import org.onosproject.k8snode.api.K8sNodeEvent;
+import org.onosproject.k8snode.api.K8sNodeState;
+import org.onosproject.k8snode.api.K8sNodeStore;
+import org.onosproject.k8snode.api.K8sNodeStoreDelegate;
+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.k8snode.api.K8sNodeEvent.Type.K8S_NODE_COMPLETE;
+import static org.onosproject.k8snode.api.K8sNodeEvent.Type.K8S_NODE_CREATED;
+import static org.onosproject.k8snode.api.K8sNodeEvent.Type.K8S_NODE_INCOMPLETE;
+import static org.onosproject.k8snode.api.K8sNodeEvent.Type.K8S_NODE_REMOVED;
+import static org.onosproject.k8snode.api.K8sNodeEvent.Type.K8S_NODE_UPDATED;
+import static org.onosproject.k8snode.api.K8sNodeState.COMPLETE;
+import static org.onosproject.k8snode.api.K8sNodeState.INCOMPLETE;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Implementation of kubernetes node store using consistent map.
+ */
+@Component(immediate = true, service = K8sNodeStore.class)
+public class DistributedK8sNodeStore
+        extends AbstractStore<K8sNodeEvent, K8sNodeStoreDelegate>
+        implements K8sNodeStore {
+
+    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.k8snode";
+
+    private static final KryoNamespace
+            SERIALIZER_K8S_NODE = KryoNamespace.newBuilder()
+            .register(KryoNamespaces.API)
+            .register(K8sNode.class)
+            .register(DefaultK8sNode.class)
+            .register(K8sNode.Type.class)
+            .register(K8sNodeState.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, K8sNode> nodeMapListener =
+            new K8sNodeMapListener();
+    private ConsistentMap<String, K8sNode> nodeStore;
+
+    @Activate
+    protected void activate() {
+        ApplicationId appId = coreService.registerApplication(APP_ID);
+        nodeStore = storageService.<String, K8sNode>consistentMapBuilder()
+                .withSerializer(Serializer.using(SERIALIZER_K8S_NODE))
+                .withName("k8s-nodestore")
+                .withApplicationId(appId)
+                .build();
+        nodeStore.addListener(nodeMapListener);
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        nodeStore.removeListener(nodeMapListener);
+        eventExecutor.shutdown();
+        log.info("Stopped");
+    }
+
+    @Override
+    public void createNode(K8sNode node) {
+        nodeStore.compute(node.hostname(), (hostname, existing) -> {
+            final String error = node.hostname() + ERR_DUPLICATE;
+            checkArgument(existing == null, error);
+            return node;
+        });
+    }
+
+    @Override
+    public void updateNode(K8sNode node) {
+        nodeStore.compute(node.hostname(), (hostname, existing) -> {
+            final String error = node.hostname() + ERR_NOT_FOUND;
+            checkArgument(existing != null, error);
+            return node;
+        });
+    }
+
+    @Override
+    public K8sNode removeNode(String hostname) {
+        Versioned<K8sNode> node = nodeStore.remove(hostname);
+        if (node == null) {
+            final String error = hostname + ERR_NOT_FOUND;
+            throw new IllegalArgumentException(error);
+        }
+        return node.value();
+    }
+
+    @Override
+    public Set<K8sNode> nodes() {
+        return ImmutableSet.copyOf(nodeStore.asJavaMap().values());
+    }
+
+    @Override
+    public K8sNode node(String hostname) {
+        return nodeStore.asJavaMap().get(hostname);
+    }
+
+    private class K8sNodeMapListener
+            implements MapEventListener<String, K8sNode> {
+
+        @Override
+        public void event(MapEvent<String, K8sNode> event) {
+
+            switch (event.type()) {
+                case INSERT:
+                    log.debug("Kubernetes node created {}", event.newValue());
+                    eventExecutor.execute(() ->
+                            notifyDelegate(new K8sNodeEvent(
+                                    K8S_NODE_CREATED, event.newValue().value()
+                    )));
+                    break;
+                case UPDATE:
+                    log.debug("Kubernetes node updated {}", event.newValue());
+                    eventExecutor.execute(() -> {
+                        notifyDelegate(new K8sNodeEvent(
+                                K8S_NODE_UPDATED,
+                                event.newValue().value()
+                        ));
+
+                        if (event.newValue().value().state() == COMPLETE) {
+                            notifyDelegate(new K8sNodeEvent(
+                                    K8S_NODE_COMPLETE,
+                                    event.newValue().value()
+                            ));
+                        } else if (event.newValue().value().state() == INCOMPLETE) {
+                            notifyDelegate(new K8sNodeEvent(
+                                    K8S_NODE_INCOMPLETE,
+                                    event.newValue().value()
+                            ));
+                        }
+                    });
+                    break;
+                case REMOVE:
+                    log.debug("Kubernetes node removed {}", event.oldValue());
+                    eventExecutor.execute(() ->
+                            notifyDelegate(new K8sNodeEvent(
+                                    K8S_NODE_REMOVED, event.oldValue().value()
+                            )));
+                    break;
+                default:
+                    // do nothing
+                    break;
+            }
+        }
+    }
+}
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/K8sNodeManager.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/K8sNodeManager.java
new file mode 100644
index 0000000..d80ef21
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/K8sNodeManager.java
@@ -0,0 +1,219 @@
+/*
+ * 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.k8snode.impl;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableSet;
+import org.onlab.util.Tools;
+import org.onosproject.cluster.ClusterService;
+import org.onosproject.cluster.LeadershipService;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.event.ListenerRegistry;
+import org.onosproject.k8snode.api.K8sNode;
+import org.onosproject.k8snode.api.K8sNode.Type;
+import org.onosproject.k8snode.api.K8sNodeAdminService;
+import org.onosproject.k8snode.api.K8sNodeEvent;
+import org.onosproject.k8snode.api.K8sNodeListener;
+import org.onosproject.k8snode.api.K8sNodeService;
+import org.onosproject.k8snode.api.K8sNodeStore;
+import org.onosproject.k8snode.api.K8sNodeStoreDelegate;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.store.service.StorageService;
+import org.osgi.service.component.ComponentContext;
+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.Modified;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
+import org.slf4j.Logger;
+
+import java.util.Dictionary;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.stream.Collectors;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+import static org.onlab.util.Tools.groupedThreads;
+import static org.onosproject.k8snode.api.K8sNodeState.COMPLETE;
+import static org.onosproject.k8snode.impl.OsgiPropertyConstants.OVSDB_PORT;
+import static org.onosproject.k8snode.impl.OsgiPropertyConstants.OVSDB_PORT_NUM_DEFAULT;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Service administering the inventory of kubernetes nodes.
+ */
+@Component(
+        immediate = true,
+        service = { K8sNodeService.class, K8sNodeAdminService.class },
+        property = {
+                OVSDB_PORT + ":Integer=" + OVSDB_PORT_NUM_DEFAULT
+        }
+)
+public class K8sNodeManager
+        extends ListenerRegistry<K8sNodeEvent, K8sNodeListener>
+        implements K8sNodeService, K8sNodeAdminService {
+
+    private final Logger log = getLogger(getClass());
+
+    private static final String MSG_NODE = "Kubernetes node %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_NODE = "Kubernetes node cannot be null";
+    private static final String ERR_NULL_HOSTNAME = "Kubernetes node hostname cannot be null";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected K8sNodeStore nodeStore;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected ClusterService clusterService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected LeadershipService leadershipService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected StorageService storageService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected DeviceService deviceService;
+
+    /** OVSDB server listen port. */
+    private int ovsdbPortNum = OVSDB_PORT_NUM_DEFAULT;
+
+    private final ExecutorService eventExecutor = newSingleThreadExecutor(
+            groupedThreads(this.getClass().getSimpleName(), "event-handler", log));
+
+    private final K8sNodeStoreDelegate delegate = new K8sNodeManager.InternalNodeStoreDelegate();
+
+    private ApplicationId appId;
+
+    @Activate
+    protected void activate() {
+        appId = coreService.registerApplication(APP_ID);
+        nodeStore.setDelegate(delegate);
+
+        leadershipService.runForLeadership(appId.name());
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        nodeStore.unsetDelegate(delegate);
+
+        leadershipService.withdraw(appId.name());
+        eventExecutor.shutdown();
+
+        log.info("Stopped");
+    }
+
+    @Modified
+    protected void modified(ComponentContext context) {
+        Dictionary<?, ?> properties = context.getProperties();
+        int updatedOvsdbPort = Tools.getIntegerProperty(properties, OVSDB_PORT);
+        if (!Objects.equals(updatedOvsdbPort, ovsdbPortNum)) {
+            ovsdbPortNum = updatedOvsdbPort;
+        }
+
+        log.info("Modified");
+    }
+
+    @Override
+    public void createNode(K8sNode node) {
+        checkNotNull(node, ERR_NULL_NODE);
+        nodeStore.createNode(node);
+        log.info(String.format(MSG_NODE, node.hostname(), MSG_CREATED));
+    }
+
+    @Override
+    public void updateNode(K8sNode node) {
+        checkNotNull(node, ERR_NULL_NODE);
+        nodeStore.updateNode(node);
+        log.info(String.format(MSG_NODE, node.hostname(), MSG_UPDATED));
+    }
+
+    @Override
+    public K8sNode removeNode(String hostname) {
+        checkArgument(!Strings.isNullOrEmpty(hostname), ERR_NULL_HOSTNAME);
+        K8sNode node = nodeStore.removeNode(hostname);
+        log.info(String.format(MSG_NODE, hostname, MSG_REMOVED));
+        return node;
+    }
+
+    @Override
+    public Set<K8sNode> nodes() {
+        return nodeStore.nodes();
+    }
+
+    @Override
+    public Set<K8sNode> nodes(Type type) {
+        Set<K8sNode> nodes = nodeStore.nodes().stream()
+                .filter(node -> Objects.equals(node.type(), type))
+                .collect(Collectors.toSet());
+        return ImmutableSet.copyOf(nodes);
+    }
+
+    @Override
+    public Set<K8sNode> completeNodes() {
+        Set<K8sNode> nodes = nodeStore.nodes().stream()
+                .filter(node -> node.state() == COMPLETE)
+                .collect(Collectors.toSet());
+        return ImmutableSet.copyOf(nodes);
+    }
+
+    @Override
+    public Set<K8sNode> completeNodes(Type type) {
+        Set<K8sNode> nodes = nodeStore.nodes().stream()
+                .filter(node -> node.type() == type &&
+                        node.state() == COMPLETE)
+                .collect(Collectors.toSet());
+        return ImmutableSet.copyOf(nodes);
+    }
+
+    @Override
+    public K8sNode node(String hostname) {
+        return nodeStore.node(hostname);
+    }
+
+    @Override
+    public K8sNode node(DeviceId deviceId) {
+        return nodeStore.nodes().stream()
+                .filter(node -> Objects.equals(node.intgBridge(), deviceId) ||
+                        Objects.equals(node.ovsdb(), deviceId))
+                .findFirst().orElse(null);
+    }
+
+    private class InternalNodeStoreDelegate implements K8sNodeStoreDelegate {
+
+        @Override
+        public void notify(K8sNodeEvent event) {
+            if (event != null) {
+                log.trace("send kubernetes node event {}", event);
+                process(event);
+            }
+        }
+    }
+}
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/OsgiPropertyConstants.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/OsgiPropertyConstants.java
new file mode 100644
index 0000000..eed9d93
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/impl/OsgiPropertyConstants.java
@@ -0,0 +1,31 @@
+/*
+ * 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.k8snode.impl;
+
+/**
+ * Name/Value constants for properties.
+ */
+public final class OsgiPropertyConstants {
+    private OsgiPropertyConstants() {
+    }
+
+    static final String OVSDB_PORT = "ovsdbPortNum";
+    static final int OVSDB_PORT_NUM_DEFAULT = 6640;
+
+    static final String AUTO_RECOVERY = "autoRecovery";
+    static final boolean AUTO_RECOVERY_DEFAULT = true;
+}
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeCodecRegister.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeCodecRegister.java
new file mode 100644
index 0000000..cb283f9
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeCodecRegister.java
@@ -0,0 +1,56 @@
+/*
+ * 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.k8snode.web;
+
+import org.onosproject.codec.CodecService;
+import org.onosproject.k8snode.api.K8sNode;
+import org.onosproject.k8snode.codec.K8sNodeCodec;
+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 static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Implementation of the JSON codec brokering service for K8sNode.
+ */
+@Component(immediate = true)
+public class K8sNodeCodecRegister {
+
+    private final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    protected CodecService codecService;
+
+    @Activate
+    protected void activate() {
+
+        codecService.registerCodec(K8sNode.class, new K8sNodeCodec());
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+
+        codecService.unregisterCodec(K8sNode.class);
+
+        log.info("Stopped");
+    }
+}
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebApplication.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebApplication.java
new file mode 100644
index 0000000..7b13666
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebApplication.java
@@ -0,0 +1,30 @@
+/*
+ * 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.k8snode.web;
+
+import org.onlab.rest.AbstractWebApplication;
+
+import java.util.Set;
+
+/**
+ * Kubernetes node REST APIs web application.
+ */
+public class K8sNodeWebApplication extends AbstractWebApplication {
+    @Override
+    public Set<Class<?>> getClasses() {
+        return getClasses(K8sNodeWebResource.class);
+    }
+}
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java
new file mode 100644
index 0000000..0367e0f
--- /dev/null
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java
@@ -0,0 +1,178 @@
+/*
+ * 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.k8snode.web;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.collect.Sets;
+import org.onosproject.k8snode.api.K8sNode;
+import org.onosproject.k8snode.api.K8sNodeAdminService;
+import org.onosproject.rest.AbstractWebResource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.POST;
+import javax.ws.rs.PUT;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.UriBuilder;
+import javax.ws.rs.core.UriInfo;
+import java.io.InputStream;
+import java.util.Set;
+
+import static com.fasterxml.jackson.databind.SerializationFeature.INDENT_OUTPUT;
+import static javax.ws.rs.core.Response.created;
+import static org.onlab.util.Tools.nullIsIllegal;
+import static org.onlab.util.Tools.readTreeFromStream;
+
+/**
+ * Handles REST API call of kubernetes node config.
+ */
+
+@Path("configure")
+public class K8sNodeWebResource extends AbstractWebResource {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final String MESSAGE_NODE = "Received node %s request";
+    private static final String NODES = "nodes";
+    private static final String CREATE = "CREATE";
+    private static final String UPDATE = "UPDATE";
+    private static final String NODE_ID = "NODE_ID";
+    private static final String DELETE = "DELETE";
+
+    private static final String HOST_NAME = "hostname";
+    private static final String ERROR_MESSAGE = " cannot be null";
+
+    private final K8sNodeAdminService adminService = get(K8sNodeAdminService.class);
+
+    @Context
+    private UriInfo uriInfo;
+
+    /**
+     * Creates a set of kubernetes nodes' config from the JSON input stream.
+     *
+     * @param input kubernetes nodes JSON input stream
+     * @return 201 CREATED if the JSON is correct, 400 BAD_REQUEST if the JSON
+     * is malformed
+     * @onos.rsModel K8sNode
+     */
+    @POST
+    @Consumes(MediaType.APPLICATION_JSON)
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response createNodes(InputStream input) {
+        log.trace(String.format(MESSAGE_NODE, CREATE));
+
+        readNodeConfiguration(input).forEach(node -> {
+            K8sNode existing = adminService.node(node.hostname());
+            if (existing == null) {
+                adminService.createNode(node);
+            }
+        });
+
+        UriBuilder locationBuilder = uriInfo.getBaseUriBuilder()
+                .path(NODES)
+                .path(NODE_ID);
+
+        return created(locationBuilder.build()).build();
+    }
+
+    /**
+     * Updates a set of kubernetes nodes' config from the JSON input stream.
+     *
+     * @param input kubernetes nodes JSON input stream
+     * @return 200 OK with the updated kubernetes node's config, 400 BAD_REQUEST
+     * if the JSON is malformed, and 304 NOT_MODIFIED without the updated config
+     * @onos.rsModel K8sNode
+     */
+    @PUT
+    @Consumes(MediaType.APPLICATION_JSON)
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response updateNodes(InputStream input) {
+        log.trace(String.format(MESSAGE_NODE, UPDATE));
+
+        Set<K8sNode> nodes = readNodeConfiguration(input);
+        for (K8sNode node: nodes) {
+            K8sNode existing = adminService.node(node.hostname());
+            if (existing == null) {
+                log.warn("There is no node configuration to update : {}", node.hostname());
+                return Response.notModified().build();
+            } else if (!existing.equals(node)) {
+                adminService.updateNode(node);
+            }
+        }
+
+        return Response.ok().build();
+    }
+
+    /**
+     * Removes a set of kubernetes nodes' config from the JSON input stream.
+     *
+     * @param hostname host name contained in kubernetes nodes configuration
+     * @return 204 NO_CONTENT, 400 BAD_REQUEST if the JSON is malformed, and
+     * 304 NOT_MODIFIED without the updated config
+     * @onos.rsModel K8sNode
+     */
+    @javax.ws.rs.DELETE
+    @Consumes(MediaType.APPLICATION_JSON)
+    @Produces(MediaType.APPLICATION_JSON)
+    @Path("{hostname}")
+    public Response deleteNodes(@PathParam("hostname") String hostname) {
+        log.trace(String.format(MESSAGE_NODE, DELETE));
+
+        K8sNode existing =
+                adminService.node(nullIsIllegal(hostname, HOST_NAME + ERROR_MESSAGE));
+
+        if (existing == null) {
+            log.warn("There is no node configuration to delete : {}", hostname);
+            return Response.notModified().build();
+        } else {
+            adminService.removeNode(hostname);
+        }
+
+        return Response.noContent().build();
+    }
+
+    private Set<K8sNode> readNodeConfiguration(InputStream input) {
+        Set<K8sNode> nodeSet = Sets.newHashSet();
+        try {
+            JsonNode jsonTree = readTreeFromStream(mapper().enable(INDENT_OUTPUT), input);
+            ArrayNode nodes = (ArrayNode) jsonTree.path(NODES);
+            nodes.forEach(node -> {
+                try {
+                    ObjectNode objectNode = node.deepCopy();
+                    K8sNode k8sNode =
+                            codec(K8sNode.class).decode(objectNode, this);
+
+                    nodeSet.add(k8sNode);
+                } catch (Exception e) {
+                    log.error("Exception occurred due to {}", e);
+                    throw new IllegalArgumentException();
+                }
+            });
+        } catch (Exception e) {
+            throw new IllegalArgumentException(e);
+        }
+
+        return nodeSet;
+    }
+}