ConfigMaps items are generated with random order

[narg95]

Description

kustomize build . produces configmap items in a random order and although it is somehow benign since it produces equivalent YAML files, it would be great if the build outputs are consistent and reproducible.

I tested it with kustomize v4.4.1

[natasha41575]

Would you mind providing a specific example with input, actual output, and expected output? This will help us write a test specifically targeted to the issue you're having.

To your point, however, we store the ConfigMap items in a Go map, which does not guarantee the order. What order are you expecting? We have two options if we want a deterministic order:

1. Alphabetical, which would be pretty simple to implement - just sort the keys before adding them to the ConfigMap data.
2. Preserve the input order. This will be a bigger change (though still small), we'd have to change the underlying data structure, and might have some extremely minor consequences on performance - but then again so would option 1.

I imagine users are expecting option 2, which we can and should do IMO.

[Shatakshi0805]

Hi, I would like to work on this.
I'm currently a beginner so could you please guide me a little so that I can get started to solve this issue

[natasha41575]

It looks like the key-value pairs are being loaded into an unordered map here:

kustomize/api/internal/generators/utils.go

Lines 37 to 56 in 25ee506

	func makeValidatedDataMap(
	ldr ifc.KvLoader, name string, sources types.KvPairSources) (map[string]string, error) {
	pairs, err := ldr.Load(sources)
	if err != nil {
	return nil, errors.WrapPrefix(err, "loading KV pairs", 0)
	}
	knownKeys := make(map[string]string)
	for _, p := range pairs {
	// legal key: alphanumeric characters, '-', '_' or '.'
	if err := ldr.Validator().ErrIfInvalidKey(p.Key); err != nil {
	return nil, err
	}
	if _, ok := knownKeys[p.Key]; ok {
	return nil, errors.Errorf(
	"configmap %s illegally repeats the key `%s`", name, p.Key)
	}
	knownKeys[p.Key] = p.Value
	}
	return knownKeys, nil
	}

We can have this function return something that keeps track of the order of key-value pairs, and preserve that order in the output.