Log rotatation proposal: placeholders - a step towards boost log sink

[Turim]

Documentation doesn't say much about the log rotation:

• components::Logging Class Reference -- btw. beware, typos: filename% MUST be %filename%, unix:socket_name% MUST be %unix:socket_name% - I didn't get it, shall I propose changes to files in https://github.com/userver-framework/userver-framework.github.io , or they have been generated already?
• Logging and Tracing

I only might see that the rotation is an option to pull the filename out (probably in order to reduce the consumed space). I'd like to have the log file at least for ~8-24-48h. Today I see current rotation as all-or-nothing approach. Is it so?

What do you think if we'd supported at least simple placeholders:

• %N ;
• %2N (%3N, %4N, %5N... etc) ; ?

So one could on new file compress and send the used file or just compress..?

[apolukhin]

I'd rather not go that direction. The functionality of logrotate is quite big https://linux.die.net/man/8/logrotate

So rather than implementing logrotate I'd recommend relying on it and using signals to notify the server to reopen the log file https://userver.tech/df/d4e/md_en_2userver_2os__signals.html