log4j2 main arguments does not get picked up by the names - log4j2

Question

I am trying to write log4j2 logs using a specific pattern:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout charset="UTF-8"
pattern="%d{HH:mm:ss.SSS} ${main:-jobId} %-5.-5level %-25.-25c{1}%-25.-25method(%5.5line) - %msg%n" />
</Console>
<RollingFile name="LogFile" fileName="${sys:logFile}"
filePattern="${sys:logFile}-%d{MM-dd-yyyy}-%i.log.gz">
<PatternLayout charset="UTF-8"
pattern="%d{yyy-MM-dd HH:mm:ss.SSS} ${main:-jobId} [%-30.-30t] %-5.-5level %-25.-25c{1}%-25.-25method(%5.5line) - %msg%n" />
<Policies>
<TimeBasedTriggeringPolicy />
<SizeBasedTriggeringPolicy size="100 MB" />
</Policies>
</RollingFile>
</Appenders>
<Loggers>
<Root level="trace">
<AppenderRef ref="LogFile" level="debug" />
<AppenderRef ref="Console" level="info" />
</Root>
</Loggers>
</Configuration>
I am passing a few arguments -o abc -d def -jobId 1234 -DlogFile /usr/lib/logpath.log This works for system parameters but the log prints as:
15:33:34.889 jobId INFO Test main ( 74) - -b
15:33:34.890 jobId INFO Test main ( 74) - -o
15:33:34.890 jobId INFO Test main ( 74) - account
15:33:34.890 jobId INFO Test main ( 74) - document
15:33:34.890 jobId INFO Test main ( 74) - -d
15:33:34.891 jobId INFO Test main ( 74) - rest
15:33:34.891 jobId INFO Test main ( 74) - -l
15:33:34.891 jobId INFO Test main ( 74) - 100
15:33:34.891 jobId INFO Test main ( 74) - -skipmd
15:33:34.891 jobId INFO Test main ( 74) - -db
15:33:34.891 jobId INFO Test main ( 74) - -jobId
15:33:34.891 jobId INFO Test main ( 74) - 1234
The code in main starts with:
public static void main(String[] args) throws Exception
{
MainMapLookup.setMainArguments(args);
for (String s : args)
logger.info(s);
...
}
I have tried using the argument based on the index and it works. However, the main argument lookup does not seem to work. Am I missing something here?
Maybe an off-topic question, what is the legit use-case of handling system variable over the main arguments in logging?

Answer 1

The reason for it not working is because there is a collision on the format between MainMapLookup by name and the StrSubstitutor default value delimiter.
${main:-jobId} gets parsed as Property main OR jobId
This is a known bug reported here: https://issues.apache.org/jira/browse/LOG4J2-1013