Logback appenders for logging data to Apache Kafka
To use logback-kafka in your project add to following to your pom.xml:
<dependency>
<groupId>com.github.ptgoetz</groupId>
<artifactId>logback-kafka</artifactId>
<version>0.1.0</version>
</dependency>To configure your application to log to kafka, add an appender entry in your logback configuration file, and specify a zookeeper host string, and kafka topic name to log to.
<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
<appender name="KAFKA"
class="com.github.ptgoetz.logback.kafka.KafkaAppender">
<topic>mytopic</topic>
<zookeeperHost>localhost:2181</zookeeperHost>
</appender>
<root level="debug">
<appender-ref ref="KAFKA" />
</root>
</configuration>By default, the Kafka appender will simply write the received log message to the kafka queue. You can override this behavior by specifying a custom formatter class:
<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
<appender name="KAFKA"
class="com.github.ptgoetz.logback.kafka.KafkaAppender">
<topic>foo</topic>
<zookeeperHost>localhost:2181</zookeeperHost>
<!-- specify a custom formatter -->
<formatter class="com.github.ptgoetz.logback.kafka.formatter.JsonFormatter">
<!--
Whether we expect the log message to be JSON encoded or not.
If set to "false", the log message will be treated as a string,
and wrapped in quotes. Otherwise it will be treated as a parseable
JSON object.
-->
<expectJson>true</expectJson>
</formatter>
</appender>
<root level="debug">
<appender-ref ref="KAFKA" />
</root>
</configuration>Formatters simply need to implement the com.github.ptgoetz.logback.kafka.formatter.Formatter interface:
package com.github.ptgoetz.logback.kafka.formatter;
import ch.qos.logback.classic.spi.ILoggingEvent;
public interface Formatter {
String format(ILoggingEvent event);
}You can find the ch.qos.logback.classic.spi.ILoggingEvent javadoc here.