Setting Up logentries for OSGi Applications in Apache Karaf

What You'll Get

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How To

Get an account at logentries. For a start, you'll get free forever account for 1 GB of logs per month, which is cool. :-)

We need to patch leappender-1-1.5.jar by adding OSGi manifest headers and attach it as fragment to pax-logging-service. (in CentOS/Amazon Linux, jar requires java-1.7.0-openjdk-devel yum package)

wget 'https://github.com/downloads/logentries/le_java/leappender-1.1.5.jar'unzip -d leappender leappender-1.1.5.jarmkdir -vp leappender/META-INF
nano leappender/META-INF/MANIFEST.MF

Replace with:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: com.logentries.leappender
Bundle-SymbolicName: com.logentries.leappender
Bundle-Version: 1.1.5
Created-By: 1.7.0_09-icedtea (Oracle Corporation)
Export-Package: com.logentries.log4j;uses:="org.apache.log4j.spi";version="1.1.5"
Import-Package: org.apache.log4j,org.apache.log4j.spi
Fragment-Host: org.ops4j.pax.logging.pax-logging-service

rm -v leappender-1.1.5.bar; jar -cvfm leappender-1.1.5.bar leappender/META-INF/MANIFEST.MF -C leappender .

# Wrap it first using bnd
wget -O bnd.jar 'http://search.maven.org/remotecontent?filepath=biz/aQute/bnd/1.50.0/bnd-1.50.0.jar'
java -jar bnd.jar wrap leappender-1.1.5.jar

our appender bundle should be present in the system folder and defined in etc/startup.properties.

The system folder has a “Maven repo like” structure. So you have to copy with:


system/groupId/artifactId/version/artifactId-version.jar

In our example, it means:

mkdir -vp system/com/logentries/leappender/1.1.5/cp -v leappender-1.1.5.bar system/com/logentries/leappender/1.1.5/leappender-1.1.5.jar

and in etc/startup.properties, we define the appender bundle just before the pax-logging-service bundle:

...
org/ops4j/pax/logging/pax-logging-api/1.7.0/pax-logging-api-1.7.0.jar=8com/logentries/leappender/1.1.5/leappender-1.1.5.jar=8 org/ops4j/pax/logging/pax-logging-service/1.7.0/pax-logging-service-1.7.0.jar=8
...

Edit Karaf's etc/org.ops4j.pax.logging.cfg :

log4j.rootLogger = INFO, out, le, osgi:*
...# Logentries appender
log4j.appender.le=com.logentries.log4j.LeAppender
log4j.appender.le.Token=LOGENTRIES_TOKEN
log4j.appender.le.Debug=true
log4j.appender.le.layout=org.apache.log4j.PatternLayout
log4j.appender.le.layout.ConversionPattern=%d{ISO8601} | %-5.5p | %-16.16t | %-32.32c{1} | %-32.32C %4L | %X{bundle.id} - %X{bundle.name} - %X{bundle.version} | %m%n
#log4j.appender.le.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss ZZZ} %-5p: %F:%L %m

Note: The LOGENTRIES_TOKEN parameter can be found beside the logfile which we created earlier.

I can't get this to work automatically, so on first Karaf launch you'll get ClassNotFoundException, then you'll need to install it:

install mvn:com.logentries/leappender/1.1.5
bundle-level <id> 8

Now it should work.

At first launch you'll get a ClassNotFound exception. Shutdown Karaf and relaunch, it should work. (this was due to the leappender-1.1.5.jar in deploy/ folder, the system one still doesn't work automatically)

Happy logging! :-)

References:

• https://logentries.com/doc/java/
• http://blog.nanthrax.net/2012/12/create-custom-log4j-appender-for-karaf-and-pax-logging/
• http://karaf.922171.n3.nabble.com/Using-custom-log4j-appenders-under-Karaf-2-1-4-td2781811.html