Add an option in kustomize lib to suppress the deprecation warnings.

[liuwh08]

Eschewed features

• This issue is not requesting templating, unstuctured edits, build-time side-effects from args or env vars, or any other eschewed feature.

What would you like to have added?

A knob or loger option to suppress the warinning emitted by kustomize lib (not the binary).

Why is this needed?

Currently our binary directly calls kustomize.Build() and each call will write deprecation warning to stderr and our binary calls multiple times of Build(). It looks spamming and probably a bit ominous to our end user.

Can you accomplish the motivating task without this feature, and if so, how?

No, it's hard coded to stderr.

What other solutions have you considered?

The alternative is the deprecation of var but it would take sometime to finish on our side as it's not a full feature parity to repalcements. (We finished the jsonPatch and base to resources pretty quickly.)

Anything else we should know?

No response

Feature ownership

• I am interested in contributing this feature myself! 🎉

[natasha41575]

I think it's fine to add the knob for suppressing warnings to kustomize as a library. I don't think we should add this knob to the kustomize binary, but folks who are integrating kustomize as a library into their own tool may have reasons to suppress these, particularly if the use of kustomize is an implementation detail that they might not want to expose to users.

/triage accepted
/kind feature
/help

[k8s-ci-robot]

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In response to this:

I think it's fine to add the knob for suppressing warnings to kustomize as a library. I don't think we should add this knob to the kustomize binary, but folks who are integrating kustomize as a library into their own tool may have reasons to suppress these, particularly if the use of kustomize is an implementation detail that they might not want to expose to users.

/triage accepted
/kind feature
/help

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[davidbaena]

I implemented a code snippet to try to reproduce the warning traces, however this code does not prints any warning:

import (
	"log"
	"os"

	"sigs.k8s.io/kustomize/api/krusty"
	"sigs.k8s.io/kustomize/kyaml/filesys"
)

func main() {
	writer := os.Stdout

	k := krusty.MakeKustomizer(krusty.MakeDefaultOptions())

	fSys := filesys.MakeFsOnDisk()
	m, err := k.Run(fSys, "/ABSOLUTE/PATH/kustomization-foo")
	if err != nil {
		log.Fatalf("Error: %v", err)
		return
	}

	yaml, err := m.AsYaml()
	if err != nil {
		log.Fatalf("Error: %v", err)
		return
	}

	_, err = writer.Write(yaml)
	if err != nil {
		log.Fatalf("Error: %v", err)
		return
	}
}

kustomization-foo contains the "hello world" example: https://github.com/kubernetes-sigs/kustomize/tree/master/examples/helloWorld

@natasha41575 Is this the way to import kustomize as a lib? I'm interested on fix this issue

Thanks a lot!

[davidbaena]

/assign

[davidbaena]

I reviewed again the code, and perhaps these flags should be suppressed with a knob when used as lib:

https://github.com/davidbaena/kustomize/blob/790ca0e7b66aae32c4ab6258709f15be471b15b4/kustomize/commands/build/build.go#L112

	msg := "Error marking flag '%s' as deprecated: %v"
	err := cmd.Flags().MarkDeprecated(flagReorderOutputName,
		"use the new 'sortOptions' field in kustomization.yaml instead.")
	if err != nil {
		log.Fatalf(msg, flagReorderOutputName, err)
	}
	err = cmd.Flags().MarkDeprecated(managedByFlag,
		"The flag `enable-managedby-label` has been deprecated. Use the `managedByLabel` option in the `buildMetadata` field instead.")
	if err != nil {
		log.Fatalf(msg, managedByFlag, err)
	}

Do you mean these warnings?

[liuwh08]

It's emiited in https://github.com/kubernetes-sigs/kustomize/blob/master/api/internal/target/kusttarget.go#L70 and directly to stderr. Ideally it should take a logger (like slog.Logger) and the caller could pass a caller here.

[davidbaena]

Ok, I'm going to implement that solution
Thanks!

[davidbaena]

This issue has been implemented in this PR:
#5466