What happened:

controller-gen crd fails with:

must apply minitems to an array
must apply maxitem to an array

I’m new to this area, so this might be me misunderstanding something. I noticed LabelSelector.MatchLabels is a map but has +kubebuilder:validation:MinItems/MaxItems markers:

// api/v1/shared_types.go
type LabelSelector struct {
    // ...
    // +kubebuilder:validation:MinItems=1
    // +kubebuilder:validation:MaxItems=64
    MatchLabels map[LabelKey]LabelValue `json:"matchLabels,omitempty"`
}

Refs:

• gateway-api-inference-extension/api/v1/shared_types.go

  Line 140 in 2b313ac

  // +kubebuilder:validation:MinItems=1

• https://github.com/kubernetes-sigs/gateway-api-inference-extension/blob/bfd979d7576acf3f121efeae01920cb09d09cbe8/api/v1/shared_types.go#L136-L145

What you expected to happen:
CRD generation succeeds. If cardinality on a map is intended, I believe MinProperties/MaxProperties would be the correct markers, or the map cardinality check could be omitted.

How to reproduce it (as minimally and precisely as possible):

1. Use Gateway API Inference Extension v1.0.0 or v1.0.1.
2. Run controller-gen crd over types including LabelSelector (or vendor the module and run with paths=./...).
3. Observe the error above.

Anything else we need to know?:

• controller-tools appears to enforce MinItems/MaxItems only on arrays: https://github.com/kubernetes-sigs/controller-tools/blob/main/pkg/crd/markers/validation.go
• The generated CRD YAML in this repo models matchLabels as an object with additionalProperties constraints on values (which looks correct) and does not use MinItems/MaxItems on the map:

  • gateway-api-inference-extension/config/crd/bases/inference.networking.k8s.io_inferencepools.yaml

    Lines 128 to 151 in bfd979d

    	matchLabels:
    	additionalProperties:
    	description: |-
    	LabelValue is the value of a label. This is used for validation
    	of maps. This matches the Kubernetes label validation rules:
    	* must be 63 characters or less (can be empty),
    	* unless empty, must begin and end with an alphanumeric character ([a-z0-9A-Z]),
    	* could contain dashes (-), underscores (_), dots (.), and alphanumerics between.
    	Valid values include:
    	* MyValue
    	* my.name
    	* 123-my-value
    	maxLength: 63
    	minLength: 0
    	pattern: ^(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?$
    	type: string
    	description: |-
    	MatchLabels contains a set of required {key,value} pairs.
    	An object must match every label in this map to be selected.
    	The matching logic is an AND operation on all entries.
    	type: object
    	required:

• Questions: Is MinItems/MaxItems on a map field intentional here, or should it be MinProperties/MaxProperties? If unintended, I’m happy to open a PR adjusting the markers.

Environment:

• Kubernetes version (use kubectl version): N/A
• Inference extension version (use git describe --tags --dirty --always): v1.0.0 / v1.0.1
• Cloud provider or hardware configuration: N/A
• Install tools: controller-gen (version aligned with repo; issue still reproduces)
• Others: none