Mike

“While Docker automatically captures logs for you, it does not also rotate them. In fact, currently none of the provided packages set up any log rotation. You’ll need to do that yourself in most cases. Rather frustratingly, Docker also does not respond to a signal to tell it to reopen logs. If you send it the standard HUP signal, it will instead restart all the containers, which is not what you want. The current best practice for rotation of Docker logs is to have logrotate use the copytruncate method to copy the logfile and then truncate it in place. There are open bugs against docker asking for a better solution.”
― Karl Matthias, Docker: Up & Running: Shipping Reliable Containers in Production