use interface instead *logrus.Logger in plugin klogrus

[peczenyj]

Hello

We use some wrappers around *logrus.Logger and we don't want to write a wrapper each time we need to set the kafka logger

Instead, since most of the time we use logrus.FieldLogger with some extra methods, I decided to send this small contribution where we can use this minimal interface

// FieldLogger interface.
type FieldLogger interface {
	logrus.FieldLogger
	GetLevel() logrus.Level
}

The result is still compatible with logrus, but on steroids.

I was thinking in use the pure logrus.FieldLogger and store the log level (using two constructors, for instance) but I think we need to react to possible changes in the log level in runtime. This solution is cleaner

Also I add one test based on kslog plugin.

Enjoy

[twmb]

Technically this is a "major" change since the input type changed. What do you think about making this a minor change by adding a new API, NewFieldLogger?

[peczenyj]

Sure, will work on it

[peczenyj]

done @twmb

[twmb]

Nice, thanks

[twmb]

Can you squash all of these changes into one commit? Also still need the period dropped on that doc line I commented on

[peczenyj]

squash done

[twmb]

nice thanks, I'll release this likely today

[twmb]

I haven't forgotten, just got behind. Why changes today?

[peczenyj]

I had some free time :)

[twmb]

Apologies on the delay, lgtm, I'll tag imminently.

[twmb]

Released as plugin/klogrus/v1.1.0. I think v1.10.0 was tagged incorrectly with an @ rather than a /, so at least v1.1.0 is correct.