How to configure a log pattern via JVM argument?

[Treutler]

Dear community,
I have a Java Gradle project and I want to configure the pattern of my log statements with a JVM argument.
When I add a JVM argument in the form -Dlogging.encoder.console.pattern=%d{HH:mm:ss.SSS} - %msg%n I see no effect.
How can I configure the pattern of my log statements with a JVM argument correctly?

Example project: https://github.com/Treutler/rainbowgum-test
Line of interest: https://github.com/Treutler/rainbowgum-test/blob/main/build.gradle.kts#L19C10-L19C69

Thanks in advance for any helpful suggestions.

[agentgt]

@Treutler I think the github repos you linked are private as I can't see them.

[agentgt]

I can't see your project but you are missing this property (first one):

logging.appender.console.encoder=pattern
logging.encoder.console.pattern=%d{HH:mm:ss.SSS} - %msg%n

I found it rather hard to get gradlew run to get system properties so I ask chatgpt and this is what it came up for me and works:

//build.gradle
tasks.named('run') {
    systemProperty 'logging.appender.console.encoder', 'pattern'
    systemProperty 'logging.encoder.console.pattern', '%d{HH:mm:ss.SSS} - %msg%n'
}

This is probably something we should fix though. OOB we do not use the pattern encoder for speed reasons so you need to tell the console appender to use the pattern encoder.

[Treutler]

The argument logging.appender.console.encoder=pattern solved the issue.
For the sake of this discussion, I made the corresponding repository public and pushed the fix as suggested.
Thanks!

[agentgt]

In the future you will not need logging.appender.console.encoder=pattern as pattern will become the default encoder for OutputType = CONSOLE provided of course the pattern module is found which for most it will be.

Although being explicit (stating the encoder) is nice enough people have tripped on it that I think it justifies this implicit behavior.

Thanks for your input as it helps me make Rainbow Gum easier to use!