[LOG4J2-1694] Allow to easily add fields with fixed values to JSON output

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7, 2.8, 2.8.1, 2.8.2, 2.9.0, 2.9.1
• Fix Version/s: 2.10.0
• Component/s: Layouts
• Labels: extra-field json
• Assignee: Mikael Ståldal
• Reporter: Raimar Falke
• Created: 11/Nov/16 18:46
• Updated: 05/Apr/18 18:19
• Resolved: 26/Sep/17 20:16

Description

The Logback JSON Encoder has a feature which allows to specify JSON fields with fixed values. Link: https://github.com/logstash/logstash-logback-encoder#loggingevent_custom_global

Example:

<encoder class="net.logstash.logback.encoder.LogstashEncoder">
  <customFields>{"appname":"myWebservice","roles":["customerorder","auth"],"buildinfo":{"version":"Version 0.1.0-SNAPSHOT","lastcommit":"75473700d5befa953c45f630c6d9105413c16fe1"}}</customFields>
</encoder>

This is a very convenient way to specify fixed attributes like application, service or environment.

So far I don't see such a possibility in log4j.

Issue Links

• relates to: LOG4J2-667 Add customization for JSON Layout keys and values
• relates to: LOG4J2-1752 Add ISO8601 format to timestamp in JSONLayout
• links to: GitHub PR
• links to: GitHub Pull Request #110