/var/log/syslog not rotating

Question

Our log file /var/log/syslog does not seem to be rotating, even though the logrotate config /etc/logrotate.d/rsyslog exists:

/var/log/syslog
{
    rotate 7
    daily
    missingok
    notifempty
    delaycompress
    compress
    postrotate
        reload rsyslog >/dev/null 2>&1 || true
    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
        reload rsyslog >/dev/null 2>&1 || true
    endscript
}

See, the syslog log file is 600M with no old files or compressed.

-rw-r-----  1 syslog   adm    600M Nov  9 20:30 syslog

Answer 1

I found the problem, somehow su directive got removed from /etc/logrotate.conf, so needed to add:

# use the syslog group by default, since this is the owning group
# of /var/log/syslog.
su root syslog

Answer 2

I had a similar problem and it seems to have been caused by some kind of incompatibility between the logrotate configuration and the new systemd replacement for sysv/init.d

I had to edit the /etc/logrotate.d/rsyslog and replace

invoke-rc.d rsyslog rotate > /dev/null

with

systemctl kill -s HUP --kill-who=main rsyslog.service

the previous line looked like it was working, and said so, but did not manage to get rsyslog to reopen its logfiles.

Answer 3

Based on Samuel's comment, modified /usr/lib/rsyslog/rsyslog-rotate

#!/bin/sh

if [ -d /run/systemd/system ]; then
    systemctl kill -s HUP --kill-who=main rsyslog.service
else
    invoke-rc.d rsyslog rotate > /dev/null
fi