Install

apt-get install -y logrotate

/etc/logrotate.d/rsyslog

/var/log/syslog
{
	rotate 7
	daily
        size 100M
	missingok
	notifempty
	delaycompress
	compress
	postrotate
		/usr/lib/rsyslog/rsyslog-rotate
	endscript
}

/var/log/mail.info
/var/log/mail.warn
/var/log/mail.err
/var/log/mail.log
/var/log/daemon.log
/var/log/kern.log
/var/log/auth.log
/var/log/user.log
/var/log/lpr.log
/var/log/cron.log
/var/log/debug
/var/log/messages
{
	rotate 4
	weekly
	missingok
	notifempty
	compress
	delaycompress
	sharedscripts
	postrotate
		/usr/lib/rsyslog/rsyslog-rotate
	endscript
}

Force logrotate

logrotate -vf /etc/logrotate.conf

Manuall compress logfiles

find /srv/log/*/202*/0{1..3}/ -type f -size +128M | xargs gzip