Folio Log file retention

Okapi : Okapi logging properties are defined in /etc/folio/okapi/log4j2.properties . The default setting is log rotation, a log rollover strategy, and keeping the logs a maximum of 10 days.
Modules : The module (assuming it logs to standard out / error) is not involved in any log file rotation or retention policy. The module publishes and then immediately forgets the log entry.
- Docker consumes log entries to stdout and stderror of the modules. At that point, log rotation is controlled by the Docker host’s config for stdout and stderror.
- One way to configure log retention policies is to configure all the docker containers to use syslog as the log_drive. In that way, logs all go to the host OS's syslog tagged with the container name, and the rotation is being handled by the system's normal logrotate function.
- In K8s clusters set up by Rancher, RancherOS provides a built in logrotate container that makes use of logrotate(8) to rotate system logs. This is called on an hourly basis by the system-cron container.
- The default Folio core Java modules use log4j2 .