I’m looking for a really simple, lightweight way of persisting logs from a docker container running in kubernetes. I just want the stdout (and stderr I guess) to go to persistent disk, I don’t want anything else for analysing the logs, to send them over the internet to a third party, etc. as part of this.

Having done some reading I’ve been considering a DaemonSet with the application container, but then another container which has /var/lib/docker/containers mounted and also a persistent volume (maybe NFS) mounted too. That container would then need a way to copy logs from the default docker JSON logging driver in /var/lib/docker/containers to the persistent volume, maybe rsync running regularly.

Would that work (presumably if the rsync container goes down it's going to miss stuff because nothing's queuing, perhaps that's ok rather than trying to queue potentially huge amounts of logs), is this a sensible approach for the desired outcome? It’s only for one or two containers if that makes a difference. Thanks.