How to automatically change the name of a file on a daily basis

Question

I am new to Linux/CentOS and right now I am running into a little problem.

My CentOS7 Server logs all Maillogs, via Logrotate, on a daily basis and moves them to the folder /var/log/old_maillogs. Right now the logs are saved with a name similar to this:

Maillog-20230721

I would like their names to change, based on how old they are, so that if the Log is one day old it's named:

Maillog-1

And one the day after that, the files name changes to:

Maillog-2

And so on.

Is this even possible, if so, what would be the smartest way to get it working? I have read a lot about scripts that get executed once per day, but then again, how do I code the script, so that it recognizes how many logs are in the folder?

This is my current config:

/var/log/maillog{ daily rotate 365 postrotate Systemctl restart rsyslog.service endscript mailfirst olddi /var/log/old_maillog } 

Answer 1

Please refer logrotate man page option "start count"

start count

This is the number to use as the base for rotation. For example, if you specify 0, the logs will be created with a .0 extension as they are rotated from the original log files. If you specify 9, log files will be created with a .9, skipping 0-8. Files will still be rotated the number of times specified with the count directive.

Answer 2

As @asktyagi already stated. The right parameter to use is "start count".

Initially it didn't work for me, that's because I didn't disable the parameter for "use data extension for rotated files", which is called nodateext.

So the working config looks like this:

/var/log/maillog{ daily rotate 365 postrotate Systemctl restart rsyslog.service endscript mailfirst olddi /var/log/old_maillog start 1 nodateext } 

This config saves logs on a daily basis and renames the extension to the number, that is equivalent to how old the log is.

So on day 1 it's called - maillog.1

And on day 2 it's called - maillog.2

And so on.