CodeReview - Initial Commit for Kafka Integration Application
1. Partial REST API implementation
2. Partial Event Manager backend implementation
Change-Id: Ieaf703f7a3f6e296aea8ffcf155c7a1b603236ca
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/EventExporterManager.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/EventExporterManager.java
new file mode 100644
index 0000000..53d9173
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/EventExporterManager.java
@@ -0,0 +1,132 @@
+/*
+ * 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.onosproject.kafkaintegration;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Map;
+import java.util.UUID;
+
+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.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.kafkaintegration.api.EventExporterService;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
+import org.onosproject.kafkaintegration.errors.InvalidApplicationException;
+import org.onosproject.kafkaintegration.errors.InvalidGroupIdException;
+import org.onosproject.kafkaintegration.errors.UnsupportedEventException;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.link.LinkService;
+import org.onosproject.store.serializers.KryoNamespaces;
+import org.onosproject.store.service.Serializer;
+import org.onosproject.store.service.StorageService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Implementation of Event Exporter Service.
+ *
+ */
+@Component(immediate = true)
+@Service
+public class EventExporterManager implements EventExporterService {
+
+ private final Logger log = LoggerFactory.getLogger(getClass());
+
+ // Stores the currently registered applications for event export service.
+ // Map of Appname to groupId
+ private Map<ApplicationId, EventSubscriberGroupId> registeredApps;
+
+ private static final String REGISTERED_APPS = "registered-applications";
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected DeviceService deviceService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected LinkService linkService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected CoreService coreService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected StorageService storageService;
+
+ private static final String NOT_YET_SUPPORTED = "Not yet supported.";
+
+ private ApplicationId appId;
+
+ @Activate
+ protected void activate() {
+ appId = coreService
+ .registerApplication("org.onosproject.kafkaintegration");
+
+ registeredApps = storageService
+ .<ApplicationId, EventSubscriberGroupId>consistentMapBuilder()
+ .withName(REGISTERED_APPS)
+ .withSerializer(Serializer.using(KryoNamespaces.API,
+ EventSubscriberGroupId.class,
+ UUID.class))
+ .build().asJavaMap();
+
+ log.info("Started");
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ log.info("Stopped");
+ }
+
+ @Override
+ public EventSubscriberGroupId registerListener(String appName) {
+
+ // TODO: Remove it once ONOS provides a mechanism for external apps
+ // to register with the core service. See Jira - 4409
+ ApplicationId externalAppId = coreService.registerApplication(appName);
+
+ return registeredApps.computeIfAbsent(externalAppId,
+ (key) -> new EventSubscriberGroupId(UUID
+ .randomUUID()));
+
+ }
+
+ @Override
+ public void unregisterListener(String appName) {
+ ApplicationId externalAppId =
+ checkNotNull(coreService.getAppId(appName));
+ registeredApps.remove(externalAppId);
+ }
+
+ @Override
+ public void subscribe(EventSubscriber subscriber)
+ throws UnsupportedEventException, InvalidGroupIdException,
+ InvalidApplicationException {
+
+ throw new UnsupportedOperationException(NOT_YET_SUPPORTED);
+ }
+
+ @Override
+ public void unsubscribe(EventSubscriber subscriber)
+ throws InvalidGroupIdException, InvalidApplicationException {
+
+ throw new UnsupportedOperationException(NOT_YET_SUPPORTED);
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/EventExporterService.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/EventExporterService.java
new file mode 100644
index 0000000..3ca5414
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/EventExporterService.java
@@ -0,0 +1,64 @@
+/**
+ * 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.onosproject.kafkaintegration.api;
+
+import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
+import org.onosproject.kafkaintegration.errors.InvalidApplicationException;
+import org.onosproject.kafkaintegration.errors.InvalidGroupIdException;
+import org.onosproject.kafkaintegration.errors.UnsupportedEventException;
+
+/**
+ * APIs for subscribing to Onos Event Messages.
+ */
+public interface EventExporterService {
+
+ /**
+ * Registers the external application to receive events generated in ONOS.
+ *
+ * @param appName Application Name
+ * @return unique consumer group identifier
+ */
+ EventSubscriberGroupId registerListener(String appName);
+
+ /**
+ * Removes the Registered Listener.
+ *
+ * @param appName Application Name
+ */
+ void unregisterListener(String appName);
+
+ /**
+ * Allows registered listener to subscribe for a specific event type.
+ *
+ * @param subscriber Subscription data containing the event type
+ * @throws UnsupportedEventException
+ * @throws InvalidGroupIdException
+ * @throws InvalidApplicationException
+ */
+ void subscribe(EventSubscriber subscriber)
+ throws UnsupportedEventException, InvalidGroupIdException,
+ InvalidApplicationException;
+
+ /**
+ * Allows the registered listener to unsubscribe for a specific event.
+ *
+ * @param subscriber Subscription data containing the event type
+ * @throws InvalidGroupIdException
+ * @throws InvalidApplicationException
+ */
+ void unsubscribe(EventSubscriber subscriber)
+ throws InvalidGroupIdException, InvalidApplicationException;
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriber.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriber.java
new file mode 100644
index 0000000..95647e7
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriber.java
@@ -0,0 +1,99 @@
+/**
+ * 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.onosproject.kafkaintegration.api.dto;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+
+import org.onosproject.kafkaintegration.api.dto.OnosEvent.Type;
+
+/**
+ * Representation of a subscription to an event type.
+ *
+ */
+public final class EventSubscriber {
+ private final String appName;
+ private final EventSubscriberGroupId subscriberGroupId;
+ private final Type eventType;
+
+ /**
+ * Creates a new Event Subscriber.
+ *
+ * @param name Application Name
+ * @param groupId Subscriber group id of the application
+ * @param eventType ONOS event type
+ */
+ public EventSubscriber(String name, EventSubscriberGroupId groupId,
+ Type eventType) {
+ this.appName = checkNotNull(name);
+ this.subscriberGroupId = checkNotNull(groupId);
+ this.eventType = checkNotNull(eventType);
+ }
+
+ /**
+ * Returns the Application Name.
+ *
+ * @return application name
+ */
+ public String appName() {
+ return appName;
+ }
+
+ /**
+ * Returns the Subscriber Group Id.
+ *
+ * @return Subscriber Group Id
+ */
+ public EventSubscriberGroupId subscriberGroupId() {
+ return subscriberGroupId;
+ }
+
+ /**
+ * Returns the Event type.
+ *
+ * @return ONOS Event Type
+ */
+ public Type eventType() {
+ return eventType;
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(appName, subscriberGroupId, eventType);
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (o instanceof EventSubscriber) {
+ EventSubscriber sub = (EventSubscriber) o;
+ if (sub.appName.equals(appName)
+ && sub.subscriberGroupId.equals(subscriberGroupId)
+ && sub.eventType.equals(eventType)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ @Override
+ public String toString() {
+ return toStringHelper(this).add("appName", appName)
+ .addValue(subscriberGroupId.toString())
+ .add("eventType", eventType).toString();
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriberGroupId.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriberGroupId.java
new file mode 100644
index 0000000..e0dd204
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriberGroupId.java
@@ -0,0 +1,70 @@
+/**
+ * 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.onosproject.kafkaintegration.api.dto;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+import java.util.UUID;
+
+/**
+ * Wrapper Object for storing the consumer group id. Group ids are used by
+ * external applications when consuming events from Kafka server.
+ *
+ */
+public final class EventSubscriberGroupId {
+ private final UUID id;
+
+ /**
+ * Creates a new Subscriber Group Id.
+ *
+ * @param uuid representing the group id.
+ */
+ public EventSubscriberGroupId(UUID uuid) {
+ id = checkNotNull(uuid);
+ }
+
+ /**
+ * Returns the Group Id of the subscriber.
+ *
+ * @return uuid representing the group id.
+ */
+ public UUID getId() {
+ return id;
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (o instanceof EventSubscriberGroupId) {
+ EventSubscriberGroupId sub = (EventSubscriberGroupId) o;
+ if (sub.id.equals(id)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(id);
+ }
+
+ @Override
+ public String toString() {
+ return toStringHelper(this).add("subscriberGroupId", id).toString();
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/OnosEvent.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/OnosEvent.java
new file mode 100644
index 0000000..ff1d27e
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/OnosEvent.java
@@ -0,0 +1,43 @@
+/**
+ * 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.onosproject.kafkaintegration.api.dto;
+
+import org.onosproject.event.AbstractEvent;
+
+import com.google.protobuf.GeneratedMessage;
+
+/**
+ * Represents the converted Onos Event data into GPB format.
+ *
+ */
+public class OnosEvent extends AbstractEvent<OnosEvent.Type, GeneratedMessage> {
+
+ /**
+ * Creates a new Onos Event.
+ *
+ * @param type The Type of Onos Event
+ * @param subject Protobuf message corresponding to the Onos Event
+ */
+ public OnosEvent(Type type, GeneratedMessage subject) {
+ super(type, subject);
+ }
+
+ /**
+ * List of Event Types supported.
+ */
+ public enum Type {
+ DEVICE, LINK;
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/package-info.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/package-info.java
new file mode 100644
index 0000000..9066935
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/package-info.java
@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+/**
+ * Immutable Data Transfer Objects.
+ */
+package org.onosproject.kafkaintegration.api.dto;
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/package-info.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/package-info.java
new file mode 100644
index 0000000..250108c
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/package-info.java
@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+/**
+ * API definitions for the Application.
+ */
+package org.onosproject.kafkaintegration.api;
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidApplicationException.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidApplicationException.java
new file mode 100644
index 0000000..290f537
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidApplicationException.java
@@ -0,0 +1,30 @@
+/**
+ * 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.onosproject.kafkaintegration.errors;
+
+/**
+ * Represents that an unregistered application trying to subscribe to ONOS
+ * events.
+ *
+ */
+public class InvalidApplicationException extends RuntimeException {
+
+ private static final long serialVersionUID = 1L;
+
+ public InvalidApplicationException(String message) {
+ super(message);
+ }
+
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidGroupIdException.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidGroupIdException.java
new file mode 100644
index 0000000..fd0657b
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidGroupIdException.java
@@ -0,0 +1,29 @@
+/**
+ * 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.onosproject.kafkaintegration.errors;
+
+/**
+ * The groupId given by the external application is already in use by another
+ * application or groupId does not exist.
+ *
+ */
+public class InvalidGroupIdException extends RuntimeException {
+
+ private static final long serialVersionUID = 1L;
+
+ public InvalidGroupIdException(String message) {
+ super(message);
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/UnsupportedEventException.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/UnsupportedEventException.java
new file mode 100644
index 0000000..73312b4
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/UnsupportedEventException.java
@@ -0,0 +1,28 @@
+/**
+ * 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.onosproject.kafkaintegration.errors;
+
+/**
+ * Event Type requested for subscription is not supported/available for export.
+ *
+ */
+public class UnsupportedEventException extends RuntimeException {
+
+ private static final long serialVersionUID = 1L;
+
+ public UnsupportedEventException(String message) {
+ super(message);
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/package-info.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/package-info.java
new file mode 100644
index 0000000..28427d4
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/package-info.java
@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+/**
+ * Application specific Exception classes.
+ */
+package org.onosproject.kafkaintegration.errors;
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/package-info.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/package-info.java
new file mode 100644
index 0000000..72f4843
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/package-info.java
@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+/**
+ * API implementation classes.
+ */
+package org.onosproject.kafkaintegration;
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/EventExporterWebResource.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/EventExporterWebResource.java
new file mode 100644
index 0000000..e3b7cc6
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/EventExporterWebResource.java
@@ -0,0 +1,167 @@
+/**
+ * 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.onosproject.kafkaintegration.rest;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static javax.ws.rs.core.Response.Status.BAD_REQUEST;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.DELETE;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.kafkaintegration.api.EventExporterService;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
+import org.onosproject.rest.AbstractWebResource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+/**
+ * Rest Interfaces for subscribing/unsubscribing to event notifications.
+ */
+@Path("kafkaService")
+public class EventExporterWebResource extends AbstractWebResource {
+
+ private final Logger log = LoggerFactory.getLogger(getClass());
+ public static final String JSON_NOT_NULL = "Registration Data cannot be empty";
+ public static final String REGISTRATION_SUCCESSFUL = "Registered Listener successfully";
+ public static final String DEREGISTRATION_SUCCESSFUL = "De-Registered Listener successfully";
+ public static final String EVENT_SUBSCRIPTION_SUCCESSFUL = "Event Registration successfull";
+ public static final String EVENT_SUBSCRIPTION_REMOVED = "Event De-Registration successfull";
+
+ /**
+ * Registers a listener for Onos Events.
+ *
+ * @param appName The application trying to register
+ * @return 200 OK with UUID string which should be used as Kafka Consumer
+ * Group Id
+ * @onos.rsModel KafkaRegistration
+ */
+ @POST
+ @Produces(MediaType.APPLICATION_JSON)
+ @Consumes(MediaType.APPLICATION_JSON)
+ @Path("register")
+ public Response registerKafkaListener(String appName) {
+
+ EventExporterService service = get(EventExporterService.class);
+
+ EventSubscriberGroupId groupId = service.registerListener(appName);
+
+ log.info("Registered app {}", appName);
+
+ // TODO: Should also return Kafka server information.
+ // Will glue this in when we have the config and Kafka modules ready
+ return ok(groupId.getId().toString()).build();
+ }
+
+ /**
+ * Unregisters a listener for Onos Events.
+ *
+ * @param appName The application trying to unregister
+ * @return 200 OK
+ * @onos.rsModel KafkaRegistration
+ */
+ @DELETE
+ @Produces(MediaType.APPLICATION_JSON)
+ @Consumes(MediaType.APPLICATION_JSON)
+ @Path("unregister")
+ public Response removeKafkaListener(String appName) {
+ EventExporterService service = get(EventExporterService.class);
+
+ service.unregisterListener(appName);
+
+ return ok(DEREGISTRATION_SUCCESSFUL).build();
+ }
+
+ /**
+ * Creates subscription to a specific Onos event.
+ *
+ * @param input Subscription Data in Json format
+ * @return 200 OK if successful or 400 BAD REQUEST
+ * @onos.rsModel KafkaSubscription
+ */
+ @POST
+ @Produces(MediaType.APPLICATION_JSON)
+ @Path("subscribe")
+ public Response subscribe(InputStream input) {
+
+ EventExporterService service = get(EventExporterService.class);
+
+ try {
+ EventSubscriber sub = parseSubscriptionData(input);
+ service.subscribe(sub);
+ } catch (Exception e) {
+ log.error(e.getMessage());
+ return Response.status(BAD_REQUEST).entity(e.getMessage()).build();
+ }
+
+ return ok(EVENT_SUBSCRIPTION_SUCCESSFUL).build();
+ }
+
+ /**
+ * Parses Json Subscription Data from the external application.
+ *
+ * @param node node within the parsed json tree.
+ * @return parsed DTO object
+ * @throws IOException
+ */
+ private EventSubscriber parseSubscriptionData(InputStream input)
+ throws IOException {
+
+ ObjectMapper mapper = new ObjectMapper();
+ ObjectNode node = (ObjectNode) mapper.readTree(input);
+
+ checkNotNull(node, JSON_NOT_NULL);
+
+ JsonCodec<EventSubscriber> codec = codec(EventSubscriber.class);
+ return codec.decode(node, this);
+ }
+
+ /**
+ * Deletes subscription from a specific Onos event.
+ *
+ * @param input data in json format
+ * @return 200 OK if successful or 400 BAD REQUEST
+ * @onos.rsModel KafkaSubscription
+ */
+ @DELETE
+ @Produces(MediaType.APPLICATION_JSON)
+ @Path("unsubscribe")
+ public Response unsubscribe(InputStream input) {
+
+ EventExporterService service = get(EventExporterService.class);
+
+ try {
+ EventSubscriber sub = parseSubscriptionData(input);
+ service.subscribe(sub);
+ } catch (Exception e) {
+ log.error(e.getMessage());
+ return Response.status(BAD_REQUEST).entity(e.getMessage()).build();
+ }
+
+ return ok(EVENT_SUBSCRIPTION_REMOVED).build();
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/SubscriberCodec.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/SubscriberCodec.java
new file mode 100644
index 0000000..f7a02b4
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/SubscriberCodec.java
@@ -0,0 +1,59 @@
+/**
+ * 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.onosproject.kafkaintegration.rest;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.UUID;
+
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
+import org.onosproject.kafkaintegration.api.dto.OnosEvent.Type;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+/**
+ * Codec for encoding/decoding a Subscriber object to/from JSON.
+ *
+ */
+public final class SubscriberCodec extends JsonCodec<EventSubscriber> {
+
+ // JSON field names
+ private static final String NAME = "appName";
+ private static final String GROUP_ID = "groupId";
+ private static final String EVENT_TYPE = "eventType";
+
+ @Override
+ public ObjectNode encode(EventSubscriber data, CodecContext context) {
+ checkNotNull(data, "Subscriber cannot be null");
+ return context.mapper().createObjectNode().put(NAME, data.appName())
+ .put(GROUP_ID, data.subscriberGroupId().getId().toString())
+ .put(EVENT_TYPE, data.eventType().toString());
+ }
+
+ @Override
+ public EventSubscriber decode(ObjectNode json, CodecContext context) {
+ String name = json.path(NAME).asText();
+ String groupId = json.path(GROUP_ID).asText();
+ EventSubscriberGroupId subscriberGroupId = new EventSubscriberGroupId(UUID
+ .fromString(groupId));
+ String eventType = json.path(EVENT_TYPE).asText();
+
+ return new EventSubscriber(name, subscriberGroupId,
+ Type.valueOf(eventType));
+ }
+}
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/package-info.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/package-info.java
new file mode 100644
index 0000000..424c4a5
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/rest/package-info.java
@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+/**
+ * REST API Definitions.
+ */
+package org.onosproject.kafkaintegration.rest;