Add check verifying labels and annotation are not confused (#5718)

[Szymongib]

No indication that labels and annotations were set incorrectly.

Check if labels set by user are not set as annotations and vice versa.

Unit tests and manual test.

Fixes #5718

Signed-off-by: Szymon Gibała szymongib@gmail.com

[alpeb]

Looking good 👍
What do you think about moving the functions in healthcheck.go to a new file like healthcheck_labels.go so we keep this file size under control?
Also it'd be great to add a test case into healthcheck_test.go with a couple of resources violating these checks so we can ensure the output of the checks is right 😉

[dadjeibaah]

@Szymongib, thanks for putting this PR together! This is going to be super useful. I think the change is looking great. I left a few suggestions for your consideration.

[Szymongib]

Thanks a lot for review @alpeb and @dadjeibaah!

@alpeb a questions regarding your comment

Also it'd be great to add a test case into healthcheck_test.go with a couple of resources violating these checks so we can ensure the output of the checks is right 😉

There are already some tests violating the check that expect the error https://github.com/linkerd/linkerd2/pull/5943/files#diff-932ac70a02fcd5e0e4b89b0a03f1302aeac2d162ea1b7ae7a074839d24e6dbf5R1921 do you suggest to add assertion of the actual error message?

[alpeb]

Ah sorry I missed that, but yeah, it'd be nice to check the errors themselves as we do in the other negative tests in that file.

[Szymongib]

I have adjusted PR to address your comments, let me know if you have any other concerns or see ways to improve.

Changes:

• Move labels and annotations checks to healthcheck_labels.go file
• Split services check to two to align error messages with pods check - one check for labels the other for annotations
• Change error messages according to suggestions
• Check if error message is correct in tests

[dadjeibaah]

This looks great! Thanks for making those updates. I had one minor nit but that's pretty much it

[alpeb]

Thanks @Szymongib , looks great! 👍

[Pothulapati]

LGTM! Thanks for taking this up! 🔥 @Szymongib

Can you also update the linkerd/website repo with the troubleshooting docs for the newly added hint anchors? They could just mention an explanation on what labels and annotations the CLI expects for pods and services?

[Szymongib]

Hi @Pothulapati, sure!
I have created the PR linkerd/website#1046 let me know if that is correct place and if description is sufficient.