I am trying to create a custom appender using Decanter as mentioned here. My goal is to listen to all logs output by karaf bundles and display it in console. I am using Karaf 3.0.4 under Apache Servicemix 6.1.0
I have added Decanter feature repository in Karaf & then installed collector-log and appender-log as mentioned in the Decanter documentation.
My custom appender looks like below:-
package com.jabong.karaf.decanter.appender.elklog;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventHandler;
public class ELKLogAppender implements EventHandler {
@Override
public void handleEvent(Event event) {
for (String name : event.getPropertyNames()) {
System.out.println("Custom Debraj" + name + ":" + event.getProperty(name));
}
}
}
My Activator looks like below:-
package com.jabong.karaf.decanter.appender.elklog;
import java.util.Dictionary;
import java.util.Hashtable;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
public class Activator implements BundleActivator {
private ServiceRegistration registration;
@Override
public void start(BundleContext bundleContext) {
ELKLogAppender appender = new ELKLogAppender();
Dictionary<String, String> properties = new Hashtable<>();
properties.put(EventConstants.EVENT_TOPIC, "decanter/collect/*");
registration = bundleContext.registerService(EventHandler.class, appender, properties);
}
@Override
public void stop(BundleContext bundleContext) {
if (registration != null) {
registration.unregister();
}
}
}
My pom.xml looks like below:-
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.jabong.karaf.decanter.appender</groupId>
<artifactId>elklog</artifactId>
<version>0.0.1</version>
<packaging>bundle</packaging>
<name>Apache Karaf :: Decanter :: Appender :: ELKLog</name>
<dependencies>
<!-- OSGi -->
<dependency>
<groupId>org.osgi</groupId>
<artifactId>org.osgi.core</artifactId>
<version>4.3.1</version>
</dependency>
<dependency>
<groupId>org.osgi</groupId>
<artifactId>org.osgi.compendium</artifactId>
<version>4.3.1</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.felix</groupId>
<artifactId>maven-bundle-plugin</artifactId>
<version>2.4.0</version>
<inherited>true</inherited>
<extensions>true</extensions>
<configuration>
<instructions>
<Bundle-SymbolicName>${project.artifactId}</Bundle-SymbolicName>
<Bundle-Version>${project.version}</Bundle-Version>
<Bundle-Activator>com.jabong.karaf.decanter.appender.elklog.Activator</Bundle-Activator>
<Import-Package>
*
</Import-Package>
</instructions>
</configuration>
</plugin>
</plugins>
</build>
</project>
I was able to install the bundle correctly in Karaf by placing it in deploy folder.
332 | Active | 80 | 0.0.1 | basecomponent
333 | Active | 80 | 1.0.1 | Apache Karaf :: Decanter :: API
334 | Active | 80 | 1.0.1 | Apache Karaf :: Decanter :: Collector :: Log
337 | Active | 80 | 1.0.1 | Apache Karaf :: Decanter :: Appender :: Log
339 | Active | 80 | 0.0.1 | Apache Karaf :: Decanter :: Appender :: ELKLog
340 | Active | 80 | 2.4.0 | Commons IO
341 | Active | 80 | 1.0.1 | Apache Karaf :: Decanter :: Collector :: File
My org.ops4j.pax.logging.cfg in Karaf looks like below:-
# Root logger
log4j.rootLogger=INFO, out, osgi:VmLogAppender
log4j.throwableRenderer=org.apache.log4j.OsgiThrowableRenderer
# To avoid flooding the log when using DEBUG level on an ssh connection and doing log:tail
log4j.logger.org.apache.sshd.server.channel.ChannelSession = INFO
# CONSOLE appender not used by default
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ISO8601} | %-5.5p | %-16.16t | %-32.32c{1} | %X{bundle.id} - %X{bundle.name} - %X{bundle.version} | %X | %m%n
# File appender
log4j.appender.out=org.apache.log4j.RollingFileAppender
log4j.appender.out.layout=org.apache.log4j.PatternLayout
log4j.appender.out.layout.ConversionPattern=%d{ISO8601} | %-5.5p | %-16.16t | %-32.32c{1} | %X{bundle.id} - %X{bundle.name} - %X{bundle.version} | %X | %m%n
log4j.appender.out.file=${karaf.data}/log/servicemix.log
log4j.appender.out.append=true
log4j.appender.out.maxFileSize=100MB
log4j.appender.out.maxBackupIndex=10
# Sift appender
log4j.appender.sift=org.apache.log4j.sift.MDCSiftingAppender
log4j.appender.sift.key=bundle.name
log4j.appender.sift.default=servicemix
log4j.appender.sift.appender=org.apache.log4j.FileAppender
log4j.appender.sift.appender.layout=org.apache.log4j.PatternLayout
log4j.appender.sift.appender.layout.ConversionPattern=%d{ISO8601} | %-5.5p | %-16.16t | %-32.32c{1} | %X | %m%n
log4j.appender.sift.appender.file=${karaf.data}/log/$\\{bundle.name\\}.log
log4j.appender.sift.appender.append=true
But I am not seeing any message on the console. Even though I am seeing many logs in data/servicemix.log
In etc/org.ops4j.pax.logging.cfg, changing to
log4j.rootLogger=INFO, out, osgi:*
from
log4j.rootLogger=INFO, out, osgi:VmLogAppender
solved the issue.