test: prevent logging panics from failing tests

[theunrepentantgeek]

Description

Depending on environmental timing issues, it's sometimes possible for goroutines launched as a part of a test to still be running (at least momentarily) after the test completes.

If one of those goroutines tries to log, the resulting panic can cause the entire test suite to fail.

This PR adds a safety wrapper around the logger to capture and suppress those panics, eliminating this cause of test flakes.

How was this change tested?

Full unit test coverage of safeTestingT, plus make test locally (but noting that test flakes were normally observed during CI).

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

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[DerekFrank]

Looks like this broke all of the tests. Does this belong in Karpenter or should this be something we cut an issue for upstream in go or the test frameworks?

I haven't seen this happen personally, I'd like to see some evidence if possible

[DerekFrank]

See above comment

[theunrepentantgeek]

Looks like this broke all of the tests.

Fixed - the test target in Makefile passes a number of ginkgo specific command line flags which weren't being interpreted because my tests are pure Go style. I added suite_test.go to consume those - other packages with Go style tests do the same.

Does this belong in Karpenter or should this be something we cut an issue for upstream in go or the test frameworks?

I created uber-go/zap #1526 about two months ago, but it hasn't gained much traction (if any). I have the changes in a WIP branch and will create a PR, but I'm not confident it will be merged.

I haven't seen this happen personally, I'd like to see some evidence if possible

Three examples from CI runs for karpenter-provider-azure: [Link | Link | Link]

We've suppressed a number of these test flakes by disabling certain log calls, effectively we're following this model:

if !testing {
    // log goes here
}

But this has issues of it's own.