Log rotation with logrotate: prevent disk fill from application logs

Application log files grow indefinitely and eventually fill the disk, causing the application to crash or behave incorrectly.

Create a logrotate config for your application:

# /etc/logrotate.d/myapp
/var/log/myapp/*.log {
    daily
    rotate 14
    compress
    delaycompress
    missingok
    notifempty
    sharedscripts
    postrotate
        # Tell the app to reopen log files
        systemctl reload myapp 2>/dev/null || true
        # Or if using pm2:
        # pm2 reloadLogs
    endscript
}

Test without executing:

logrotate -d /etc/logrotate.d/myapp

# Force rotation now
logrotate -f /etc/logrotate.d/myapp

# Check last run status
cat /var/lib/logrotate/status | grep myapp

delaycompress keeps the previous log uncompressed for one cycle so that log shippers (like filebeat) can finish reading before compression. postrotate ensures the app opens new file descriptors pointing to the new file.