logfile overwritten when symlink + delaycompress used

[drzraf]

I found to have lost many logs due to a setup specificity:
I had:

vhost1/logs/access.log
vhost2/logs/access.log
vhost3 -> vhost1

and this kind of configuration :

/vhosts/vhost*/logs/*.log {
       monthly
        missingok
        rotate 48
        compress
        delaycompress
        notifempty
        create 660 root
        sharedscripts
        postrotate
                if [ -f /var/run/apache2.pid ]; then
                        /etc/init.d/apache2 reload > /dev/null
                fi
        endscript
}

I found that vhosts1/logs/access.log.1 was always empty, and thus subsequently compressed files were empty too.
If I run logrotate on a specific vhost, the access.log.1 is created and not null.
I'm still not sure about the root cause but I my guess is that the following happens:

• vhost1/logs/access.log is moved to vhost1/logs/access.log.1
• vhost2 is treated
• vhost3/logs/access.log, now empty, is moved anyway and overrwrite vhost3/logs/access.log.1 (which actually is vhost1/logs/access.log.1)

All my vhosts having symlink were affected by the issue.
Using the (quite old) logrotate 3.7.8-4ubuntu2.2

[jankaluza]

This is caused by a way how logrotate works. It first checks the state of all logs matching the pattern and then rotates them. So vhost3 is also valid for a rotation during this step. Once it starts rotating the logs, it has no clue (currently), that it has rotated it already as part of vhost1 rotation.

I will think what to do with that, but I don't want to change the rotation strategy completely...

[zuf]

Is it possible to add option skip symlinks?

[Alexander-Shukaev]

Any chance to ever see an option for ignoring symbolic links (as already suggested by @zuf)?

[Alexander-Shukaev]

I see that prerotate also does not check whether script exit status is non-zero. So there is no way to generically implement prerequisite/precondition checks. Either introduction of such generic script option, e.g. predicate or prerequisite or precondition, or notiflink should resolve this issue.

[kdudka]

I see that prerotate also does not check whether script exit status is non-zero.

I believe it does.

So there is no way to generically implement prerequisite/precondition checks.

Could the firstaction script be used for this?

[cgzones]

Any chance to ever see an option for ignoring symbolic links

Maybe something like: https://github.com/logrotate/logrotate/compare/master...cgzones:ignore_duplicate_symlinks?expand=1

Edit: it might be racy and won't work if a parent directory is also a symlink (e.g. /var/log/httpd/vhost3/logs/access.log, where /var/log/httpd is a symlink to /var/log/apache2 and /var/log/httpd/vhost3 a symlink to /var/log/httpd/vhost1)