Improve Logging in Libbeat

[ruflin]

Libbeat uses its own logging implementation. But the library has its limitation. This issue should be used as a meta issue to discuss potential issues with the library and also if moving forward the internal library should be improved or potentially replaced by either just and interface or a specific logging library as a dependency.

There are a few related Github issues which should be tracked with this Github issue:

• logrotate should be optional #2764
• Make permisson on logfile configureable #4295
• How to dynamically change the logging level without having to restart a beat? #4678
• Metrics logging should support gauges #3114 (fixed via a whitelist of gauges names (temp hack))
• Better support and documentation for stderr logging (journald) #1807
• Include selector name in debug output #5042

This issue will be updated with new information.

[ruflin]

@andrewkroh Could you have a look at the above ot check how many boxes we can check with your new implementation?

[andrewkroh]

I ticked two more checkboxes.

[jlind23]

Backlog grooming: Closing it for now until further activity, can still be reopened if needed.

[acbox]

This issue was closed with these two outstanding:

• How to dynamically change the logging level without having to restart a beat? #4678
• Better support and documentation for stderr logging (journald) #1807

I'm here specifically because I would also like log level to be changed dynamically via HTTP. Any plans for this on the horizon? Thanks.

[andrewkroh]

@acbox I saw a recent change at elastic/elastic-agent-libs#82 that makes the level changeable. I don't know if there are plans to expose this via an API.