[LOG4J2-2600] Declarative Groovy Configuration DSL

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: Configurators
• External issue URL: https://lists.apache.org/thread.html/95e34968249b40cad33b30ae8648ffbeb8c5575b7652aee0d037c5d0@%3Cdev.logging.apache.org%3E
• Epic Link: Plugin Ergonomics
• Assignee: Matt Sicker
• Reporter: Matt Sicker
• Created: 04/May/19 16:52
• Updated: 01/Dec/23 23:17
• Resolved: 01/Dec/23 23:17

Description

Borrowing the general Groovy syntax used in Stapler, a declarative Groovy syntax comparable to the existing XML/JSON/YAML syntax tree for writing configuration files.

For example, a minimal binding implementation might look something like this. Starting with an example XML configuration:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
  <Appenders>
    <Console name="Console" target="SYSTEM_OUT">
      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
    </Console>
  </Appenders>
  <Loggers>
    <Logger name="com.foo.Bar" level="trace">
      <AppenderRef ref="Console"/>
    </Logger>
    <Root level="error">
      <AppenderRef ref="Console"/>
    </Root>
  </Loggers>
</Configuration>

This would look like this in the declarative Groovy DSL:

configuration(status: 'warn') {
  appenders {
    console(name: 'Console', target: 'SYSTEM_OUT') {
      patternLayout(pattern: '%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n')
    }
  }
  loggers {
    logger(name: 'com.foo.Bar', level: 'trace') {
      appenderRef(ref: 'Console')
    }
    root(level: 'error') {
      appenderRef(ref: 'Console')
    }
  }
}

While it is not the goal of this particular feature to enable scripted configuration, it does open the possibility for such.

Issue Links

• is related to: LOG4J2-1531 Change attribute and component values from String to Object
• links to: GitHub Pull Request #274