adding_validation.md

Adding a validation to a resources schema

Note: By default, when creating a resource with apiserver-boot create group version resource a validation function will be created in the versioned <kind>_types.go file.

To add server side validation for your resource override the Validate function on the <Kind>Strategy struct in the version package.

Example:

File: pkg/apis/<group>/<version>/bar_types.go

// Resource Validation
func (BarStrategy) Validate(ctx request.Context, obj runtime.Object) field.ErrorList {
	bar := obj.(*Bar)
	errors := field.ErrorList{}
	if ... {
		errors = append(errors, field.Invalid(
			field.NewPath("spec", "Field"),
			*bar.Spec.Field,
			"Error message"))
	}
	return errors
}

Anatomy of validation

A default <Kind>Strategy is generated for each resource with an embedded default Validation function. To specify custom validation logic, override the embedded implementation.

Cast the object type to your resource Kind

bar := obj.(*Bar)

---

Use the field.Invalid function to specify errors scoped to fields in the object.

field.Invalid(field.NewPath("spec", "Field"), *bar.Spec.Field, "Error message")

Note: To specify a different struct type for validation, specify stragegy in the resource comment. e.g. // +resource:path=<resource>,strategy=<Kind>Strategy. This struct type must have a single field of type builders.DefaultStorageStrategy for the generated code to correctly create an pass it into the wiring.