How to have log4j.properties read env variables

Question

This should just be a quick question. I am wondering if this syntax would be correct.

Inside log4j.properties

log4j.rootLogger=${ROOT_LOGGER:INFO}, console

So what I'm trying to achieve is to have a ROOT_LOGGER env variable and if it's not present, fallback to INFO . I know this works in .yaml files, so just wondering if the same applies here.

Answer 1

Long time but Im going to put my found solution here.

we can add vars on properties like:

• ${sys:some.property:-default_value}
• ${env:ENV_NAME:-default_value}

build.gragle dependencies

dependencies {

    implementation "org.apache.logging.log4j:log4j-api:2.14.1"
    implementation "org.apache.logging.log4j:log4j-core:2.14.1"

}

log4j2.properties

appender.consoledev.type=Console
appender.consoledev.name=CONSOLEDEV
appender.consoledev.layout.type=PatternLayout
appender.consoledev.layout.pattern=%d{HH:mm:ss.sss} %5p %20logger{36} : %msg%n

loggers=logapp
logger.logapp.name=${sys:logging.package:-com.test}
logger.logapp.level=${sys:logging.level:-DEBUG}
logger.logapp.additivity=false
logger.logapp.appenderRef.consoledev.ref=CONSOLEDEV

running jar with args

java -jar -Dlogging.level=INFO -Dlogging.package=com.test.MainClass  test.jar

java -jar -Dlogging.level=INFO -Dlogging.package=com.test test.jar

java -jar -Dlogging.level=DEBUG -Dlogging.package=root  test.jar