Use customLabel if it exists

[ycombinator]

Fixes #6407

[rashidkpc]

Maybe we want + label here too?

[ycombinator]

Perhaps. I think it depends on what we expect users to put in for label. For instance, in the issue for this PR — #6407 — @tbragin used "SD" as the custom label. Assuming that's short for "standard deviation", it wouldn't make sense to include in the avg title, right?

[rashidkpc]

Yeah, but you'd usually use the custom label to describe what sort of data the line represents. The design of the customLabel property really isn't ideal for multi value metrics unfortunately :-(

[tbragin]

So i didn't even realize that adding "Standard Deviation" as a metric adds its own "Average" column. I'm not sure why... we have an explicit option for adding "Average" which has its own custom label (see screenshot).

Just brainstorming, here are some possible options I see:

(1) Apply the label entered for standard deviation custom label box in the "Lower Standard Deviation or [metric]" and "Upper Standard Deviation of [metric]" columns only by replacing only "Standard Deviation of [metric]"
(2) Alternatively, consider separate labels for each column if suggestion above doesn't work.
(3) Orthogonally, consider no longer add the "Average" column when user adds "Standard Deviation" relying on explicit configuration there. We can make this change in a major version as long as we release note it, I assume.

My preference would be doing (1) and optionally (3), but would love others to weigh in.

[rashidkpc]

I believe the reason std deviation currently add its own average is because early versions of kibana didn't support more than one metric agg per chart, but now of course they do.

Agree with @tbragin, let's do 1, but also do 3.

[rashidkpc]

Also, do 3 in a different pull

[ycombinator]

Thanks @rashidkpc and @tbragin. This PR implements (1) but I want to add a unit test for it. So removing review label for now.

[ycombinator]

Unit test added (with much help from @Bargs — thank you!)

[ycombinator]

jenkins, test it

[spalger]

LGTM