| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 net.lr.reactive.components.appender.kafka; |
| |
| import java.util.Dictionary; |
| |
| import org.apache.kafka.clients.producer.ProducerRecord; |
| import org.apache.karaf.decanter.api.marshaller.Marshaller; |
| import org.apache.karaf.rcomp.api.RComponent; |
| import org.apache.karaf.rcomp.api.ReqComp; |
| 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.Reference; |
| import org.osgi.service.event.Event; |
| import org.osgi.service.event.EventConstants; |
| import org.reactivestreams.Publisher; |
| import org.reactivestreams.Subscriber; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import reactor.core.publisher.Flux; |
| |
| @ReqComp("kafka") |
| @Component( |
| name = "appender.kafka", |
| immediate = true, |
| //configurationPolicy = ConfigurationPolicy.REQUIRE, |
| property = EventConstants.EVENT_TOPIC + "=decanter/collect/*", |
| service=KafkaAppender.class |
| ) |
| @SuppressWarnings({ |
| "rawtypes" |
| }) |
| public class KafkaAppender { |
| private final static Logger LOGGER = LoggerFactory.getLogger(KafkaAppender.class); |
| private String topic; |
| |
| @Reference |
| Marshaller marshaller; |
| |
| @Reference(target="(name=eventAdmin)") |
| RComponent eventAdmin; |
| |
| @Reference(target="(name=kafka)") |
| RComponent kafka; |
| private Subscriber<ProducerRecord> toKafka; |
| |
| @Activate |
| public void activate(ComponentContext context) { |
| Dictionary<String, Object> config = context.getProperties(); |
| this.topic = (String)config.get("topic"); |
| if (topic == null) { |
| throw new IllegalArgumentException("Config property topic must be present."); |
| } |
| String eventTopics = (String)config.get(EventConstants.EVENT_TOPIC); |
| Publisher<Event> fromEventAdmin = eventAdmin.from(eventTopics, Event.class); |
| toKafka = kafka.to(topic, ProducerRecord.class); |
| org.slf4j.MDC.put("inLogAppender", "true"); |
| Flux.from(fromEventAdmin) |
| .doOnEach(event -> org.slf4j.MDC.put("inLogAppender", "true")) |
| //.log() |
| .map(event->toRecord(event)) |
| .doOnError(ex -> LOGGER.error(ex.getMessage(), ex)) |
| .subscribe(toKafka); |
| LOGGER.info("Kafka appender started. Listening on topic " + topic); |
| } |
| |
| public ProducerRecord<String,String> toRecord(Event event) { |
| String type = (String)event.getProperty("type"); |
| String data = marshaller.marshal(event); |
| return new ProducerRecord<>(topic, type, data); |
| } |
| |
| @Deactivate |
| public void close() { |
| toKafka.onComplete(); |
| } |
| |
| } |