pom modifications to appify vtn
renaming package
diff --git a/src/main/java/org/opencord/cordvtn/impl/CordVtnNodeManager.java b/src/main/java/org/opencord/cordvtn/impl/CordVtnNodeManager.java
new file mode 100644
index 0000000..c037c05
--- /dev/null
+++ b/src/main/java/org/opencord/cordvtn/impl/CordVtnNodeManager.java
@@ -0,0 +1,1029 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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.opencord.cordvtn.impl;
+
+import com.google.common.collect.Sets;
+import com.jcraft.jsch.Session;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.packet.IpAddress;
+import org.onlab.util.ItemNotFoundException;
+import org.onlab.util.KryoNamespace;
+import org.onosproject.cluster.ClusterService;
+import org.onosproject.cluster.LeadershipService;
+import org.onosproject.cluster.NodeId;
+import org.opencord.cordvtn.api.ConnectionHandler;
+import org.opencord.cordvtn.api.CordVtnConfig;
+import org.opencord.cordvtn.api.CordVtnNode;
+import org.opencord.cordvtn.api.CordVtnNodeState;
+import org.opencord.cordvtn.api.CordVtnService;
+import org.opencord.cordvtn.api.NetworkAddress;
+import org.opencord.cordvtn.api.SshAccessInfo;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DefaultAnnotations;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.Host;
+import org.onosproject.net.Port;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.behaviour.BridgeConfig;
+import org.onosproject.net.behaviour.BridgeName;
+import org.onosproject.net.behaviour.ControllerInfo;
+import org.onosproject.net.behaviour.DefaultTunnelDescription;
+import org.onosproject.net.behaviour.TunnelConfig;
+import org.onosproject.net.behaviour.TunnelDescription;
+import org.onosproject.net.behaviour.TunnelName;
+import org.onosproject.net.config.NetworkConfigEvent;
+import org.onosproject.net.config.NetworkConfigListener;
+import org.onosproject.net.config.NetworkConfigRegistry;
+import org.onosproject.net.config.NetworkConfigService;
+import org.onosproject.net.device.DeviceAdminService;
+import org.onosproject.net.device.DeviceEvent;
+import org.onosproject.net.device.DeviceListener;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.host.HostService;
+import org.onosproject.ovsdb.controller.OvsdbClientService;
+import org.onosproject.ovsdb.controller.OvsdbController;
+import org.onosproject.ovsdb.controller.OvsdbNodeId;
+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.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+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.checkNotNull;
+import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
+import static org.onlab.util.Tools.groupedThreads;
+import static org.opencord.cordvtn.impl.CordVtnPipeline.DEFAULT_TUNNEL;
+import static org.onosproject.net.Device.Type.SWITCH;
+import static org.onosproject.net.behaviour.TunnelDescription.Type.VXLAN;
+import static org.opencord.cordvtn.impl.RemoteIpCommandUtil.*;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Reads node information from the network config file and handles the config
+ * update events.
+ * Only a leader controller performs the node addition or deletion.
+ */
+@Component(immediate = true)
+@Service(value = CordVtnNodeManager.class)
+public class CordVtnNodeManager {
+
+    protected final Logger log = getLogger(getClass());
+
+    private static final KryoNamespace.Builder NODE_SERIALIZER = KryoNamespace.newBuilder()
+            .register(KryoNamespaces.API)
+            .register(CordVtnNode.class)
+            .register(NodeState.class)
+            .register(SshAccessInfo.class)
+            .register(NetworkAddress.class);
+
+    private static final String DEFAULT_BRIDGE = "br-int";
+    private static final String VPORT_PREFIX = "tap";
+    private static final String OK = "OK";
+    private static final String NO = "NO";
+
+    private static final Map<String, String> DEFAULT_TUNNEL_OPTIONS = new HashMap<String, String>() {
+        {
+            put("key", "flow");
+            put("remote_ip", "flow");
+        }
+    };
+    private static final int DPID_BEGIN = 3;
+    private static final int OFPORT = 6653;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected NetworkConfigRegistry configRegistry;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected NetworkConfigService configService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected StorageService storageService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected DeviceAdminService adminService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected OvsdbController controller;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterService clusterService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected DeviceService deviceService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected HostService hostService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected LeadershipService leadershipService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CordVtnInstanceManager instanceManager;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CordVtnPipeline pipeline;
+
+    private final ExecutorService eventExecutor =
+            newSingleThreadScheduledExecutor(groupedThreads("onos/cordvtn-node", "event-handler"));
+
+    private final NetworkConfigListener configListener = new InternalConfigListener();
+    private final DeviceListener deviceListener = new InternalDeviceListener();
+    private final MapEventListener<String, CordVtnNode> nodeStoreListener = new InternalMapListener();
+
+    private final OvsdbHandler ovsdbHandler = new OvsdbHandler();
+    private final BridgeHandler bridgeHandler = new BridgeHandler();
+
+    private ConsistentMap<String, CordVtnNode> nodeStore;
+    private ApplicationId appId;
+    private NodeId localNodeId;
+
+    private enum NodeState implements CordVtnNodeState {
+
+        INIT {
+            @Override
+            public void process(CordVtnNodeManager nodeManager, CordVtnNode node) {
+                if (!nodeManager.isOvsdbConnected(node)) {
+                    nodeManager.connectOvsdb(node);
+                } else {
+                    nodeManager.createIntegrationBridge(node);
+                }
+            }
+        },
+        BRIDGE_CREATED {
+            @Override
+            public void process(CordVtnNodeManager nodeManager, CordVtnNode node) {
+                if (!nodeManager.isOvsdbConnected(node)) {
+                    nodeManager.connectOvsdb(node);
+                } else {
+                    nodeManager.createTunnelInterface(node);
+                    nodeManager.addDataPlaneInterface(node);
+                }
+            }
+        },
+        PORTS_ADDED {
+            @Override
+            public void process(CordVtnNodeManager nodeManager, CordVtnNode node) {
+                nodeManager.setIpAddress(node);
+            }
+        },
+        COMPLETE {
+            @Override
+            public void process(CordVtnNodeManager nodeManager, CordVtnNode node) {
+                nodeManager.postInit(node);
+            }
+        },
+        INCOMPLETE {
+            @Override
+            public void process(CordVtnNodeManager nodeManager, CordVtnNode node) {
+            }
+        };
+
+        public abstract void process(CordVtnNodeManager nodeManager, CordVtnNode node);
+    }
+
+    @Activate
+    protected void activate() {
+        appId = coreService.getAppId(CordVtnService.CORDVTN_APP_ID);
+
+        localNodeId = clusterService.getLocalNode().id();
+        leadershipService.runForLeadership(appId.name());
+
+        nodeStore = storageService.<String, CordVtnNode>consistentMapBuilder()
+                .withSerializer(Serializer.using(NODE_SERIALIZER.build()))
+                .withName("cordvtn-nodestore")
+                .withApplicationId(appId)
+                .build();
+
+        nodeStore.addListener(nodeStoreListener);
+        deviceService.addListener(deviceListener);
+        configService.addListener(configListener);
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        configService.removeListener(configListener);
+        deviceService.removeListener(deviceListener);
+        nodeStore.removeListener(nodeStoreListener);
+
+        leadershipService.withdraw(appId.name());
+        eventExecutor.shutdown();
+
+        log.info("Stopped");
+    }
+
+    /**
+     * Adds or updates a new node to the service.
+     *
+     * @param node cordvtn node
+     */
+    public void addOrUpdateNode(CordVtnNode node) {
+        checkNotNull(node);
+        nodeStore.put(node.hostname(), CordVtnNode.getUpdatedNode(node, getNodeState(node)));
+    }
+
+    /**
+     * Deletes a node from the service.
+     *
+     * @param node cordvtn node
+     */
+    public void deleteNode(CordVtnNode node) {
+        checkNotNull(node);
+
+        if (isOvsdbConnected(node)) {
+            disconnectOvsdb(node);
+        }
+
+        nodeStore.remove(node.hostname());
+    }
+
+    /**
+     * Returns node initialization state.
+     *
+     * @param node cordvtn node
+     * @return true if initial node setup is completed, otherwise false
+     */
+    public boolean isNodeInitComplete(CordVtnNode node) {
+        checkNotNull(node);
+        return nodeStore.containsKey(node.hostname()) && getNodeState(node).equals(NodeState.COMPLETE);
+    }
+
+    /**
+     * Returns detailed node initialization state.
+     *
+     * @param node cordvtn node
+     * @return string including detailed node init state
+     */
+    public String checkNodeInitState(CordVtnNode node) {
+        checkNotNull(node);
+
+        if (!nodeStore.containsKey(node.hostname())) {
+            log.warn("Node {} does not exist, add node first", node.hostname());
+            return null;
+        }
+
+        Session session = connect(node.sshInfo());
+        if (session == null) {
+            log.debug("Failed to SSH to {}", node.hostname());
+            return null;
+        }
+
+        Set<IpAddress> intBrIps = getCurrentIps(session, DEFAULT_BRIDGE);
+        String result = String.format(
+                "Current state : %s%n" +
+                        "br-int created and connected to ONOS : %s (%s)%n" +
+                        "VXLAN interface added to br-int : %s%n" +
+                        "Data plane interface is added to br-int and enabled : %s (%s)%n" +
+                        "IP flushed from data plane interface : %s (%s)%n" +
+                        "Data plane IP added to br-int : %s (%s)%n" +
+                        "Local management IP added to br-int : %s (%s)",
+                node.state(),
+                isBrIntCreated(node) ? OK : NO, node.intBrId(),
+                isTunnelIntfCreated(node) ? OK : NO,
+                isDataPlaneIntfAdded(node) ? OK : NO, node.dpIntf(),
+                isInterfaceUp(session, node.dpIntf()) &&
+                        getCurrentIps(session, node.dpIntf()).isEmpty() ? OK : NO, node.dpIntf(),
+                intBrIps.contains(node.dpIp().ip()) ? OK : NO, node.dpIp().cidr(),
+                intBrIps.contains(node.localMgmtIp().ip()) ? OK : NO, node.localMgmtIp().cidr());
+
+        disconnect(session);
+
+        return result;
+    }
+
+    /**
+     * Returns the number of the nodes known to the service.
+     *
+     * @return number of nodes
+     */
+    public int getNodeCount() {
+        return nodeStore.size();
+    }
+
+    /**
+     * Returns all nodes known to the service.
+     *
+     * @return list of nodes
+     */
+    public List<CordVtnNode> getNodes() {
+        return nodeStore.values().stream().map(Versioned::value).collect(Collectors.toList());
+    }
+
+    /**
+     * Returns all nodes in complete state.
+     *
+     * @return set of nodes
+     */
+    public Set<CordVtnNode> completeNodes() {
+        return getNodes().stream().filter(this::isNodeInitComplete).collect(Collectors.toSet());
+    }
+
+    /**
+     * Returns physical data plane port number of a given device.
+     *
+     * @param deviceId integration bridge device id
+     * @return port number; null otherwise
+     */
+    public PortNumber dpPort(DeviceId deviceId) {
+        CordVtnNode node = nodeByBridgeId(deviceId);
+        if (node == null) {
+            log.warn("Failed to get node for {}", deviceId);
+            return null;
+        }
+        Port port = deviceService.getPorts(deviceId).stream()
+                .filter(p -> portName(p).contains(node.dpIntf()) &&
+                        p.isEnabled())
+                .findFirst().orElse(null);
+
+        return port == null ? null : port.number();
+    }
+
+    /**
+     * Returns physical data plane IP address of a given device.
+     *
+     * @param deviceId integration bridge device id
+     * @return ip address; null otherwise
+     */
+    public IpAddress dpIp(DeviceId deviceId) {
+        CordVtnNode node = nodeByBridgeId(deviceId);
+        if (node == null) {
+            log.warn("Failed to get node for {}", deviceId);
+            return null;
+        }
+        return node.dpIp().ip();
+    }
+
+    /**
+     * Returns tunnel port number of a given device.
+     *
+     * @param deviceId integration bridge device id
+     * @return port number
+     */
+    public PortNumber tunnelPort(DeviceId deviceId) {
+        Port port = deviceService.getPorts(deviceId).stream()
+                .filter(p -> portName(p).contains(DEFAULT_TUNNEL))
+                .findFirst().orElse(null);
+
+        return port == null ? null : port.number();
+    }
+
+    /**
+     * Returns if current node state saved in nodeStore is COMPLETE or not.
+     *
+     * @param node cordvtn node
+     * @return true if it's complete state, otherwise false
+     */
+    private boolean isNodeStateComplete(CordVtnNode node) {
+        checkNotNull(node);
+
+        // the state saved in nodeStore can be wrong if IP address settings are changed
+        // after the node init has been completed since there's no way to detect it
+        // getNodeState and checkNodeInitState always return correct answer but can be slow
+        Versioned<CordVtnNode> versionedNode = nodeStore.get(node.hostname());
+        CordVtnNodeState state = versionedNode.value().state();
+        return state != null && state.equals(NodeState.COMPLETE);
+    }
+
+    /**
+     * Initiates node to serve virtual tenant network.
+     *
+     * @param node cordvtn node
+     */
+    private void initNode(CordVtnNode node) {
+        checkNotNull(node);
+
+        NodeState state = (NodeState) node.state();
+        log.debug("Processing node: {} state: {}", node.hostname(), state);
+
+        state.process(this, node);
+    }
+
+    /**
+     * Performs tasks after node initialization.
+     * It disconnects unnecessary OVSDB connection and installs initial flow
+     * rules on the device.
+     *
+     * @param node cordvtn node
+     */
+    private void postInit(CordVtnNode node) {
+        disconnectOvsdb(node);
+        pipeline.initPipeline(node, dpPort(node.intBrId()), tunnelPort(node.intBrId()));
+
+        deviceService.getPorts(node.intBrId()).stream()
+                .filter(port -> portName(port).startsWith(VPORT_PREFIX) &&
+                        port.isEnabled())
+                .forEach(port -> instanceManager.addInstance(connectPoint(port)));
+
+        hostService.getHosts().forEach(host -> {
+            if (deviceService.getPort(host.location().deviceId(),
+                                      host.location().port()) == null) {
+                instanceManager.removeInstance(connectPoint(host));
+            }
+        });
+
+        log.info("Finished init {}", node.hostname());
+    }
+
+    /**
+     * Sets a new state for a given cordvtn node.
+     *
+     * @param node cordvtn node
+     * @param newState new node state
+     */
+    private void setNodeState(CordVtnNode node, NodeState newState) {
+        checkNotNull(node);
+
+        log.debug("Changed {} state: {}", node.hostname(), newState);
+        nodeStore.put(node.hostname(), CordVtnNode.getUpdatedNode(node, newState));
+    }
+
+    /**
+     * Checks current state of a given cordvtn node and returns it.
+     *
+     * @param node cordvtn node
+     * @return node state
+     */
+    private NodeState getNodeState(CordVtnNode node) {
+        checkNotNull(node);
+
+        if (isBrIntCreated(node) && isTunnelIntfCreated(node) &&
+                isDataPlaneIntfAdded(node) && isIpAddressSet(node)) {
+            return NodeState.COMPLETE;
+        } else if (isDataPlaneIntfAdded(node) && isTunnelIntfCreated(node)) {
+            return NodeState.PORTS_ADDED;
+        } else if (isBrIntCreated(node)) {
+            return NodeState.BRIDGE_CREATED;
+        } else {
+            return NodeState.INIT;
+        }
+    }
+
+    /**
+     * Returns connection state of OVSDB server for a given node.
+     *
+     * @param node cordvtn node
+     * @return true if it is connected, false otherwise
+     */
+    private boolean isOvsdbConnected(CordVtnNode node) {
+        checkNotNull(node);
+
+        OvsdbClientService ovsdbClient = getOvsdbClient(node);
+        return deviceService.isAvailable(node.ovsdbId()) &&
+                ovsdbClient != null && ovsdbClient.isConnected();
+    }
+
+    /**
+     * Connects to OVSDB server for a given node.
+     *
+     * @param node cordvtn node
+     */
+    private void connectOvsdb(CordVtnNode node) {
+        checkNotNull(node);
+
+        if (!nodeStore.containsKey(node.hostname())) {
+            log.warn("Node {} does not exist", node.hostname());
+            return;
+        }
+
+        if (!isOvsdbConnected(node)) {
+            controller.connect(node.hostMgmtIp().ip(), node.ovsdbPort());
+        }
+    }
+
+    /**
+     * Disconnects OVSDB server for a given node.
+     *
+     * @param node cordvtn node
+     */
+    private void disconnectOvsdb(CordVtnNode node) {
+        checkNotNull(node);
+
+        if (!nodeStore.containsKey(node.hostname())) {
+            log.warn("Node {} does not exist", node.hostname());
+            return;
+        }
+
+        if (isOvsdbConnected(node)) {
+            OvsdbClientService ovsdbClient = getOvsdbClient(node);
+            ovsdbClient.disconnect();
+        }
+    }
+
+    /**
+     * Returns OVSDB client for a given node.
+     *
+     * @param node cordvtn node
+     * @return OVSDB client, or null if it fails to get OVSDB client
+     */
+    private OvsdbClientService getOvsdbClient(CordVtnNode node) {
+        checkNotNull(node);
+
+        OvsdbClientService ovsdbClient = controller.getOvsdbClient(
+                new OvsdbNodeId(node.hostMgmtIp().ip(), node.ovsdbPort().toInt()));
+        if (ovsdbClient == null) {
+            log.trace("Couldn't find OVSDB client for {}", node.hostname());
+        }
+        return ovsdbClient;
+    }
+
+    /**
+     * Creates an integration bridge for a given node.
+     *
+     * @param node cordvtn node
+     */
+    private void createIntegrationBridge(CordVtnNode node) {
+        if (isBrIntCreated(node)) {
+            return;
+        }
+
+        List<ControllerInfo> controllers = new ArrayList<>();
+        Sets.newHashSet(clusterService.getNodes()).stream()
+                .forEach(controller -> {
+                    ControllerInfo ctrlInfo = new ControllerInfo(controller.ip(), OFPORT, "tcp");
+                    controllers.add(ctrlInfo);
+                });
+
+        String dpid = node.intBrId().toString().substring(DPID_BEGIN);
+
+        try {
+            Device device = deviceService.getDevice(node.ovsdbId());
+            if (device.is(BridgeConfig.class)) {
+                BridgeConfig bridgeConfig =  device.as(BridgeConfig.class);
+                bridgeConfig.addBridge(BridgeName.bridgeName(DEFAULT_BRIDGE), dpid, controllers);
+            } else {
+                log.warn("The bridging behaviour is not supported in device {}", device.id());
+            }
+        } catch (ItemNotFoundException e) {
+            log.warn("Failed to create integration bridge on {}", node.hostname());
+        }
+    }
+
+    /**
+     * Creates tunnel interface to the integration bridge for a given node.
+     *
+     * @param node cordvtn node
+     */
+    private void createTunnelInterface(CordVtnNode node) {
+        if (isTunnelIntfCreated(node)) {
+            return;
+        }
+
+        DefaultAnnotations.Builder optionBuilder = DefaultAnnotations.builder();
+        for (String key : DEFAULT_TUNNEL_OPTIONS.keySet()) {
+            optionBuilder.set(key, DEFAULT_TUNNEL_OPTIONS.get(key));
+        }
+
+        TunnelDescription description = new DefaultTunnelDescription(
+                null, null, VXLAN, TunnelName.tunnelName(DEFAULT_TUNNEL),
+                optionBuilder.build());
+
+        try {
+            Device device = deviceService.getDevice(node.ovsdbId());
+            if (device.is(TunnelConfig.class)) {
+                TunnelConfig tunnelConfig =  device.as(TunnelConfig.class);
+                tunnelConfig.createTunnelInterface(BridgeName.bridgeName(DEFAULT_BRIDGE), description);
+            } else {
+                log.warn("The tunneling behaviour is not supported in device {}", device.id());
+            }
+        } catch (ItemNotFoundException e) {
+            log.warn("Failed to create tunnel interface on {}", node.hostname());
+        }
+    }
+
+    /**
+     * Adds data plane interface to a given node.
+     *
+     * @param node cordvtn node
+     */
+    private void addDataPlaneInterface(CordVtnNode node) {
+        if (isDataPlaneIntfAdded(node)) {
+            return;
+        }
+
+        Session session = connect(node.sshInfo());
+        if (session == null) {
+            log.debug("Failed to SSH to {}", node.hostname());
+            return;
+        }
+
+        if (!isInterfaceUp(session, node.dpIntf())) {
+            log.warn("Interface {} is not available", node.dpIntf());
+            return;
+        }
+        disconnect(session);
+
+        try {
+            Device device = deviceService.getDevice(node.ovsdbId());
+            if (device.is(BridgeConfig.class)) {
+                BridgeConfig bridgeConfig =  device.as(BridgeConfig.class);
+                bridgeConfig.addPort(BridgeName.bridgeName(DEFAULT_BRIDGE), node.dpIntf());
+            } else {
+                log.warn("The bridging behaviour is not supported in device {}", device.id());
+            }
+        } catch (ItemNotFoundException e) {
+            log.warn("Failed to add {} on {}", node.dpIntf(), node.hostname());
+        }
+    }
+
+    /**
+     * Flushes IP address from data plane interface and adds data plane IP address
+     * to integration bridge.
+     *
+     * @param node cordvtn node
+     */
+    private void setIpAddress(CordVtnNode node) {
+        Session session = connect(node.sshInfo());
+        if (session == null) {
+            log.debug("Failed to SSH to {}", node.hostname());
+            return;
+        }
+
+        getCurrentIps(session, DEFAULT_BRIDGE).stream()
+                .filter(ip -> !ip.equals(node.localMgmtIp().ip()))
+                .filter(ip -> !ip.equals(node.dpIp().ip()))
+                .forEach(ip -> deleteIp(session, ip, DEFAULT_BRIDGE));
+
+        boolean result = flushIp(session, node.dpIntf()) &&
+                setInterfaceUp(session, node.dpIntf()) &&
+                addIp(session, node.dpIp(), DEFAULT_BRIDGE) &&
+                addIp(session, node.localMgmtIp(), DEFAULT_BRIDGE) &&
+                setInterfaceUp(session, DEFAULT_BRIDGE);
+
+        disconnect(session);
+
+        if (result) {
+            setNodeState(node, NodeState.COMPLETE);
+        }
+    }
+
+    /**
+     * Checks if integration bridge exists and available.
+     *
+     * @param node cordvtn node
+     * @return true if the bridge is available, false otherwise
+     */
+    private boolean isBrIntCreated(CordVtnNode node) {
+        return (deviceService.getDevice(node.intBrId()) != null
+                && deviceService.isAvailable(node.intBrId()));
+    }
+
+    /**
+     * Checks if tunnel interface exists.
+     *
+     * @param node cordvtn node
+     * @return true if the interface exists, false otherwise
+     */
+    private boolean isTunnelIntfCreated(CordVtnNode node) {
+        return deviceService.getPorts(node.intBrId())
+                    .stream()
+                    .filter(p -> portName(p).contains(DEFAULT_TUNNEL) &&
+                            p.isEnabled())
+                    .findAny().isPresent();
+    }
+
+    /**
+     * Checks if data plane interface exists.
+     *
+     * @param node cordvtn node
+     * @return true if the interface exists, false otherwise
+     */
+    private boolean isDataPlaneIntfAdded(CordVtnNode node) {
+        return deviceService.getPorts(node.intBrId())
+                    .stream()
+                    .filter(p -> portName(p).contains(node.dpIntf()) &&
+                            p.isEnabled())
+                    .findAny().isPresent();
+    }
+
+    /**
+     * Checks if the IP addresses are correctly set.
+     *
+     * @param node cordvtn node
+     * @return true if the IP is set, false otherwise
+     */
+    private boolean isIpAddressSet(CordVtnNode node) {
+        Session session = connect(node.sshInfo());
+        if (session == null) {
+            log.debug("Failed to SSH to {}", node.hostname());
+            return false;
+        }
+
+        Set<IpAddress> intBrIps = getCurrentIps(session, DEFAULT_BRIDGE);
+        boolean result = getCurrentIps(session, node.dpIntf()).isEmpty() &&
+                isInterfaceUp(session, node.dpIntf()) &&
+                intBrIps.contains(node.dpIp().ip()) &&
+                intBrIps.contains(node.localMgmtIp().ip()) &&
+                isInterfaceUp(session, DEFAULT_BRIDGE);
+
+        disconnect(session);
+        return result;
+    }
+
+    /**
+     * Returns connect point of a given port.
+     *
+     * @param port port
+     * @return connect point
+     */
+    private ConnectPoint connectPoint(Port port) {
+        return new ConnectPoint(port.element().id(), port.number());
+    }
+
+    /**
+     * Returns connect point of a given host.
+     *
+     * @param host host
+     * @return connect point
+     */
+    private ConnectPoint connectPoint(Host host) {
+        return new ConnectPoint(host.location().deviceId(), host.location().port());
+    }
+
+    /**
+     * Returns cordvtn node associated with a given OVSDB device.
+     *
+     * @param ovsdbId OVSDB device id
+     * @return cordvtn node, null if it fails to find the node
+     */
+    private CordVtnNode nodeByOvsdbId(DeviceId ovsdbId) {
+        return getNodes().stream()
+                .filter(node -> node.ovsdbId().equals(ovsdbId))
+                .findFirst().orElse(null);
+    }
+
+    /**
+     * Returns cordvtn node associated with a given integration bridge.
+     *
+     * @param bridgeId device id of integration bridge
+     * @return cordvtn node, null if it fails to find the node
+     */
+    private CordVtnNode nodeByBridgeId(DeviceId bridgeId) {
+        return getNodes().stream()
+                .filter(node -> node.intBrId().equals(bridgeId))
+                .findFirst().orElse(null);
+    }
+
+    /**
+     * Returns port name.
+     *
+     * @param port port
+     * @return port name
+     */
+    private String portName(Port port) {
+        return port.annotations().value("portName");
+    }
+
+    private class OvsdbHandler implements ConnectionHandler<Device> {
+
+        @Override
+        public void connected(Device device) {
+            CordVtnNode node = nodeByOvsdbId(device.id());
+            if (node != null) {
+                setNodeState(node, getNodeState(node));
+            } else {
+                log.debug("{} is detected on unregistered node, ignore it.", device.id());
+            }
+        }
+
+        @Override
+        public void disconnected(Device device) {
+            if (!deviceService.isAvailable(device.id())) {
+                log.debug("Device {} is disconnected", device.id());
+                adminService.removeDevice(device.id());
+            }
+        }
+    }
+
+    private class BridgeHandler implements ConnectionHandler<Device> {
+
+        @Override
+        public void connected(Device device) {
+            CordVtnNode node = nodeByBridgeId(device.id());
+            if (node != null) {
+                setNodeState(node, getNodeState(node));
+            } else {
+                log.debug("{} is detected on unregistered node, ignore it.", device.id());
+            }
+        }
+
+        @Override
+        public void disconnected(Device device) {
+            CordVtnNode node = nodeByBridgeId(device.id());
+            if (node != null) {
+                log.debug("Integration Bridge is disconnected from {}", node.hostname());
+                setNodeState(node, NodeState.INCOMPLETE);
+            }
+        }
+
+        /**
+         * Handles port added situation.
+         * If the added port is tunnel or data plane interface, proceed to the remaining
+         * node initialization. Otherwise, do nothing.
+         *
+         * @param port port
+         */
+        public void portAdded(Port port) {
+            CordVtnNode node = nodeByBridgeId((DeviceId) port.element().id());
+            String portName = portName(port);
+
+            if (node == null) {
+                log.debug("{} is added to unregistered node, ignore it.", portName);
+                return;
+            }
+
+            log.info("Port {} is added to {}", portName, node.hostname());
+
+            if (portName.startsWith(VPORT_PREFIX)) {
+                if (isNodeStateComplete(node)) {
+                    instanceManager.addInstance(connectPoint(port));
+                } else {
+                    log.debug("VM is detected on incomplete node, ignore it.", portName);
+                }
+            } else if (portName.contains(DEFAULT_TUNNEL) || portName.equals(node.dpIntf())) {
+                setNodeState(node, getNodeState(node));
+            }
+        }
+
+        /**
+         * Handles port removed situation.
+         * If the removed port is tunnel or data plane interface, proceed to the remaining
+         * node initialization.Others, do nothing.
+         *
+         * @param port port
+         */
+        public void portRemoved(Port port) {
+            CordVtnNode node = nodeByBridgeId((DeviceId) port.element().id());
+            String portName = portName(port);
+
+            if (node == null) {
+                return;
+            }
+
+            log.info("Port {} is removed from {}", portName, node.hostname());
+
+            if (portName.startsWith(VPORT_PREFIX)) {
+                if (isNodeStateComplete(node)) {
+                    instanceManager.removeInstance(connectPoint(port));
+                } else {
+                    log.debug("VM is vanished from incomplete node, ignore it.", portName);
+                }
+            } else if (portName.contains(DEFAULT_TUNNEL) || portName.equals(node.dpIntf())) {
+                setNodeState(node, NodeState.INCOMPLETE);
+            }
+        }
+    }
+
+    private class InternalDeviceListener implements DeviceListener {
+
+        @Override
+        public void event(DeviceEvent event) {
+
+            NodeId leaderNodeId = leadershipService.getLeader(appId.name());
+            if (!Objects.equals(localNodeId, leaderNodeId)) {
+                // do not allow to proceed without leadership
+                return;
+            }
+
+            Device device = event.subject();
+            ConnectionHandler<Device> handler =
+                    (device.type().equals(SWITCH) ? bridgeHandler : ovsdbHandler);
+
+            switch (event.type()) {
+                case PORT_ADDED:
+                    eventExecutor.execute(() -> bridgeHandler.portAdded(event.port()));
+                    break;
+                case PORT_UPDATED:
+                    if (!event.port().isEnabled()) {
+                        eventExecutor.execute(() -> bridgeHandler.portRemoved(event.port()));
+                    }
+                    break;
+                case DEVICE_ADDED:
+                case DEVICE_AVAILABILITY_CHANGED:
+                    if (deviceService.isAvailable(device.id())) {
+                        eventExecutor.execute(() -> handler.connected(device));
+                    } else {
+                        eventExecutor.execute(() -> handler.disconnected(device));
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    /**
+     * Reads cordvtn nodes from config file.
+     */
+    private void readConfiguration() {
+        CordVtnConfig config = configRegistry.getConfig(appId, CordVtnConfig.class);
+        if (config == null) {
+            log.debug("No configuration found");
+            return;
+        }
+        config.cordVtnNodes().forEach(this::addOrUpdateNode);
+    }
+
+    private class InternalConfigListener implements NetworkConfigListener {
+
+        @Override
+        public void event(NetworkConfigEvent event) {
+            NodeId leaderNodeId = leadershipService.getLeader(appId.name());
+            if (!Objects.equals(localNodeId, leaderNodeId)) {
+                // do not allow to proceed without leadership
+                return;
+            }
+
+            if (!event.configClass().equals(CordVtnConfig.class)) {
+                return;
+            }
+
+            switch (event.type()) {
+                case CONFIG_ADDED:
+                case CONFIG_UPDATED:
+                    eventExecutor.execute(CordVtnNodeManager.this::readConfiguration);
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    private class InternalMapListener implements MapEventListener<String, CordVtnNode> {
+
+        @Override
+        public void event(MapEvent<String, CordVtnNode> event) {
+            NodeId leaderNodeId = leadershipService.getLeader(appId.name());
+            if (!Objects.equals(localNodeId, leaderNodeId)) {
+                // do not allow to proceed without leadership
+                return;
+            }
+
+            CordVtnNode oldNode;
+            CordVtnNode newNode;
+
+            switch (event.type()) {
+                case UPDATE:
+                    oldNode = event.oldValue().value();
+                    newNode = event.newValue().value();
+
+                    log.info("Reloaded {}", newNode.hostname());
+                    if (!newNode.equals(oldNode)) {
+                        log.debug("New node: {}", newNode);
+                    }
+                    // performs init procedure even if the node is not changed
+                    // for robustness since it's no harm to run init procedure
+                    // multiple times
+                    eventExecutor.execute(() -> initNode(newNode));
+                    break;
+                case INSERT:
+                    newNode = event.newValue().value();
+                    log.info("Added {}", newNode.hostname());
+                    eventExecutor.execute(() -> initNode(newNode));
+                    break;
+                case REMOVE:
+                    oldNode = event.oldValue().value();
+                    log.info("Removed {}", oldNode.hostname());
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+}