tomcat-json-logging

Extension to Tomcat logging that will format the contents as JSON to be better compatible with logging environments for microservices.

TOC

1. Example
2. Installation
3. Customization
4. FAQ
5. Contributing
6. License

Example

If everything is configured correctly you will see output like this on our console:

..
{"when":"2018-11-07T14:40:58.540+0100","level":"INFO","source":"org.apache.coyote.AbstractProtocol.start(AbstractProtocol.java:488)","logger":"org.apache.coyote.http11.Http11AprProtocol","thread":"main","processId":22640,"message":"Starting ProtocolHandler [\"http-apr-8080\"]"}
{"when":"2018-11-07T14:40:58.555+0100","level":"INFO","source":"org.apache.coyote.AbstractProtocol.start(AbstractProtocol.java:488)","logger":"org.apache.coyote.ajp.AjpAprProtocol","thread":"main","processId":22640,"message":"Starting ProtocolHandler [\"ajp-apr-8009\"]"}
{"when":"2018-11-07T14:40:58.560+0100","level":"INFO","source":"org.apache.catalina.startup.Catalina.start(Catalina.java:654)","logger":"org.apache.catalina.startup.Catalina","thread":"main","processId":22640,"message":"Server startup in 859 ms"}
..

Installation

1. Download

Go to Release page and download the matching version of tomcat-juli.jar for your Tomcat version. If you have Tomcat 8.5.32 running download tomcat-juli-8.5.32.jar and so on...

Replace bin/tomcat-juli.jar inside your Tomcat distribution directory with this file.

No worries! This files is a combined version of the original Tomcat version and the new functionality.

2. Configure

Just replace the content of conf/logging.properties in your Tomcat distribution directory with the following content:

handlers = org.echocat.tjl.Handler

This will log everything directly to the console in JSON format (by default).

Customization

Using system properties or environment variables

You can either specify a system property or environment variable to change the behavior of the logging of the Tomcat. This values always override every settings in conf/logging.properties.

Available properties

System property	Environment property	Description
log.format	LOG_FORMAT	Forces a different formatter. See Available formats.
log.level	LOG_LEVEL	Forces a different global log level. Pleas refer java.util.logging.Level for different levels. For example FINE for more output while local development.

Available formats

Value	Description
json	Will use org.echocat.tjl.JsonFormatter - see Available formatter for more information.
text	Will use org.echocat.tjl.TextFormatter - see Available formatter for more information.

Using conf/logging.properties

Available properties

Name	Description	Default
org.echocat.tjl.Handler.level	Minimum level of log entries to be logged/visible. Pleas refer java.util.logging.Level for more information.	ALL
org.echocat.tjl.Handler.formatter	Formatter to format the message in the console.	org.echocat.tjl.JsonFormatter

Available formatter

Name	Description
org.echocat.tjl.JsonFormatter	Formats the whole output as JSON. One entry per line.
org.echocat.tjl.TextFormatter	Formats every entry per line in a simple way - better for local debugging.

FAQ

How to activate debug output temporary?

LOG_LEVEL=debug bin/catalina.sh run

How to make output temporarily better readable?

LOG_FORMAT=text bin/catalina.sh run

Contributing

tomcat-json-logging is an open source project by echocat. So if you want to make this project even better, you can contribute to this project on Github by fork us.

If you commit code to this project, you have to accept that this code will be released under the license of this project.

License

See the LICENSE file.