[Rottlog-develop] Re: Just an idea I had

[Frederic Connes]

Hi Stefano,

> I think I will add "custom" config file and improve much more forceday
> parameter. Probably I will rename it to "period" and let to handle somethink
> like:
> (following your ideas)
> period n                -> Each n day
> period Dd               -> Each Dth day of the month
> period <weekday>  -> Each <weekday> of the week
> period 0                -> Each time rottlog is called (*)
> period HHh              -> Each HH hour (*)
> period MMm              -> Each MM minutes (*)
>
> (*) It depends on rottlog's entries in crontab
>
> What do you think about it? 

Well, I think this would be great !
I thought about a way to generalise the rotation format.
Here's where I came to:

Basically, there are two ways to rotate the files:
- on a regular basis (every 2 days, every week...)
- on a specific date (each sunday, each 15th of the month...)

So maybe it's worth being explicit about it and use two variables:
- period
- date

The syntax of period would be:
period <x> <period>

<period> could be:
- m (minutes)
- h (hours)
- d (days)
- w (weeks)
- M (months)

If <period> is missing, assume it is d (or let it be configured in rc)
If <x> is 0, rotate each time rottlog is called
(so 0, 0d, 0h are the same)


The syntax of date would be:
date <date>

<date> could be:
- a weekday, abbreviated or not (sun or sunday)
- a monthday, abbreviated or not (sep or september)
- a day of month (1 to 31): a number
- a time (hh:mm): two numbers separated with a ":"

I think the time is useful if for example one works in a company that 
has a busy internal web site and wants to rotate the web logs at 13:00 
when people are at lunch (but not the other logs, so cron would be 
useless here).

What would be great would be to be able to AND and OR the dates, so one 
could say:
date mon,tue,wed,thu,fri 13:00,20:00
date sat 20:00

(this would then allow some very powerful enhancements like mon-fri or a 
NOT operator)


Now, about the files:

Rottlog uses 3 files, which correspond to the most current rotation 
periods. I think it is possible to extend this to something fully 
customizable.

Let use the period and date syntax to define when a configuration file 
must be read. Now you can define the daily, weekly and monthly files as 
specific cases, but you can also define any other file that fits your needs.
For example, you could define the following files:

weekly {
  period 1w
}

daily {
  period 1d
  date 04:00
}
if you call rottlog with cron every hour for some reason but want to 
rotate the files defined in daily at 04:00.

apache {
  date mon,tue,wed,thu,fri 13:00,20:00
  date sat 20:00
}
if for instance you have many virtual hosts and want to group your 
apache log files

bycron {
  period 0
}
if you want to group the files to rotate each time rottlog is called.

anotherfile {
  custom
}
custom would mean: in this file, look at the date and period in each 
logfile entry (this is for people having so specific needs that they 
would need to define one file per logfile entry: with custom, they could 
have only one file if they want, as in RedHat logrotate).


Now rottlog wouldn't make any asumption about the way the user wants to 
rotate the files, and it would allow him to define as many configuration 
files as he needs to organize the rotations, from one (with custom) to 
infinite.

Maybe the following definitions could be put in rc, and the following 
lines be added by default:

daily {
  period 1d
}
weekly {
  period 1w
}
monthly {
  period 1M
}
custom {
  custom
}


I think this way it would be possible to organize the rotation as in the 
current rottlog or as in logrotate or as the user wants to.

What do you think about it ?