I’ve been using this module for stdout logging https://www.drupal.org/project/log_stdout it works well for the docker container.

This module provides a hook for Drupal Watchdog that directs log messages to php://stdout or php://stderr for better log handling..

I’ve been using the log_stdout module for stdout logging. It works well with Docker containers.

This module provides a hook for Drupal Watchdog that directs log messages to php://stdout or php://stderr for better log handling with Docker.