Add +optional/+required markers at package and struct level for CRD v…

…alidation

Using +kubebuilder:validation:Optional/Required at the package level sets the default value for fields in that package to that value, while using the opposite marker on fields in that package sets them as an exception

pkg/crd/markers/package.go

@@ -24,5 +24,7 @@ func init() {
 	AllDefinitions = append(AllDefinitions,
 		markers.Must(markers.MakeDefinition("groupName", markers.DescribesPackage, "")),
 		markers.Must(markers.MakeDefinition("versionName", markers.DescribesPackage, "")),
+		markers.Must(markers.MakeDefinition("kubebuilder:validation:Optional", markers.DescribesPackage, struct{}{})),
+		markers.Must(markers.MakeDefinition("kubebuilder:validation:Required", markers.DescribesPackage, struct{}{})),
 	)
 }

pkg/crd/markers/validation.go

@@ -57,6 +57,8 @@ var ValidationMarkers = mustMakeAllWithPrefix("kubebuilder:validation", markers.
 	Enum(nil),
 	Format(""),
 	Type(""),
+	Required(struct{}{}),
+	Optional(struct{}{}),
 )
 
 func init() {
@@ -86,6 +88,8 @@ type UniqueItems bool
 type Enum []interface{}
 type Format string
 type Type string
+type Required struct{}
+type Optional struct{}
 
 func (m Maximum) ApplyToSchema(schema *v1beta1.JSONSchemaProps) error {
 	if schema.Type != "integer" {

pkg/crd/parser.go

@@ -121,6 +121,7 @@ func (p *Parser) indexTypes(pkg *loader.Package) {
 			Name:    info.Name,
 		}
 
+		info.PackageMarkers = pkgMarkers
 		p.Types[ident] = info
 	}); err != nil {
 		pkg.AddError(err)

pkg/crd/schema.go

@@ -342,9 +342,26 @@ func structToSchema(ctx *schemaContext, structType *ast.StructType) *v1beta1.JSO
 		fieldName := jsonOpts[0]
 		inline = inline || fieldName == "" // anonymous fields are inline fields in YAML/JSON
 
-		if !inline && !omitEmpty {
-			props.Required = append(props.Required, fieldName)
+		// if no default required mode is set, default to required
+		defaultMode := "required"
+		if ctx.info.PackageMarkers.Get("kubebuilder:validation:Optional") != nil {
+			defaultMode = "optional"
 		}
+		// if this package isn't set to optional default...
+		if defaultMode == "required" {
+			// ...everything that's not inline, omitempty, or explicitly optional is required
+			if !inline && !omitEmpty && field.Markers.Get("kubebuilder:validation:Optional") == nil {
+				props.Required = append(props.Required, fieldName)
+			}
+		}
+		// if this package isn't set to required default...
+		if defaultMode == "optional" {
+			// ...everything that isn't explicitly required is optional
+			if field.Markers.Get("kubebuilder:validation:Required") != nil {
+				props.Required = append(props.Required, fieldName)
+			}
+		}
+
 
 		propSchema := typeToSchema(ctx.ForInfo(&markers.TypeInfo{}), field.RawField.Type)
 		propSchema.Description = field.Doc

pkg/markers/zip.go

@@ -120,6 +120,8 @@ type TypeInfo struct {
 
 	// Markers are all registered markers associated with the type.
 	Markers MarkerValues
+	// PackageMarkers are the registered markers for the package of the type
+	PackageMarkers MarkerValues
 
 	// Fields are all the fields associated with the type, if it's a struct.
 	// (if not, Fields will be nil).