how do I change log level in runtime without restarting spring boot application

Question

I have deployed springboot application in PCF . I want to log the message based on the environment variable .What should I do so that the run time log level change will work

Answer 1

Changing the log level in Spring Boot 1.5+ can be done with a http-endpoint

Add

    org.springframework.boot
    spring-boot-starter-actuator

and than you can use

curl -X "POST" "http://localhost:8080/loggers/de.springbootbuch" \
     -H "Content-Type: application/json; charset=utf-8" \
     -d $'{
  "configuredLevel": "WARN"
}'  

Where everything beyond /loggers/ is the name of the logger.

If you running this in PCF it get's even better: This is directly supported from their backend.