Where to initialize logging in a Compojure app?

I have a Compojure app generated using Luminus. I want to configure logging using clj-logging-config but I'm struggling mightily with this. I put the (!set-logger) command in the init function (declared with {:ring {:init} in project.clj) but I can't explain the behavior.

If I just say (!set-logger) then it logs stuff. If I say (set-logger! :pattern "%d - %m%n") then it complains:

log4j:WARN No appenders could be found for logger (example.routes.home).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Setting the log level doesn't seem to have any effect.

Moving the (!set-logger) to the top of different modules seems to cause those modules to log as expected, but I'm failing to find the right place to put a single (!set-logger) with all the parameters I want and have it affect the whole application.

Solution

So this seems to work:

(set-loggers!
  :root {
    :level :debug
    :pattern "%d - [%p] %m%n"
  }
)

My assumption was that set-logger! by default sets the root logger. I guess that is incorrect?