StandaloneLogAppender.java

/*
 * Copyright © 2015 Cask Data, Inc.
 *
 * 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 co.cask.cdap.logging.appender.standalone;

import ch.qos.logback.classic.spi.ILoggingEvent;
import co.cask.cdap.logging.appender.LogAppender;
import co.cask.cdap.logging.appender.LogMessage;
import co.cask.cdap.logging.kafka.KafkaLogEvent;
import co.cask.cdap.logging.save.KafkaLogProcessor;

import java.util.Set;

/**
 * Wrapper around LogAppender and LogProcessor plugins to make plugins work in standalone.
 */
public class StandaloneLogAppender extends LogAppender {

  private final LogAppender appender;
  private final Set<KafkaLogProcessor> plugins;

  public StandaloneLogAppender(LogAppender appender, Set<KafkaLogProcessor> plugins) {
    this.appender = appender;
    this.plugins = plugins;
    setName("standalone-log-appender");
  }

  @Override
  protected void append(LogMessage logMessage) {
    appender.append(logMessage);
    for (KafkaLogProcessor plugin : plugins) {
      plugin.process(getKafkaLogEvent(logMessage));
    }
  }

  @Override
  public void doAppend(ILoggingEvent eventObject) {
    append(eventObject);
  }

  @Override
  public void start() {
    appender.start();
  }

  @Override
  public void stop() {
    appender.stop();
  }

  private KafkaLogEvent getKafkaLogEvent(LogMessage message) {
    // Create a Kafkalog event based on ILoggingEvent, dummy values for GenericRecord, partition and offset.
    return new KafkaLogEvent(null, message, message.getLoggingContext(), 0, -1);
  }
}