Don't crash on non-existent path values

[rexagod]

What this PR does / why we need it: Don't crash on non-existent path values in CRS.

How does this change affect the cardinality of KSM: No.

Which issue(s) this PR fixes: Fixes #1992

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[rexagod]

/cc @mrueg

[mrueg]

should this be moved to the beginning of the function so we can return the error early?

[rexagod]

That'll fail cases that expect a zero in case of nil.

kube-state-metrics/pkg/customresourcestate/registry_factory.go

Lines 425 to 439 in c493044

	// If `valueFrom` was not resolved, respect `NilIsZero` and return.
	if got == nil {
	if c.NilIsZero {
	return &eachValue{
	Labels: labels,
	Value: 0,
	}, nil
	}
	// no it means no iterables were passed down, meaning that the path resolution never happened
	if it == nil {
	return nil, fmt.Errorf("got nil while resolving path")
	}
	// Don't error if there was not a type-casting issue (`toFloat64`), but rather a failed lookup.
	return nil, nil
	}

[mrueg]

The failed lookup is handled now, can you update this comment?

[mrueg]

/lgtm

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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mrueg, rexagod

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