add support for empty shapes, used as markers

pkg/config/config.go

@@ -25,6 +25,8 @@ type Config struct {
 	// Resources contains generator instructions for individual CRDs within an
 	// API
 	Resources map[string]ResourceConfig `json:"resources"`
+	// MarkerShapes contains fields associated with empty structs used as markers
+	MarkerShapes []string `json:"marker_shapes,omitempty"`
 	// CRDs to ignore. ACK generator would skip these resources.
 	Ignore IgnoreSpec `json:"ignore"`
 	// Contains generator instructions for individual API operations.
@@ -151,6 +153,17 @@ func (c *Config) GetCustomMapFieldMembers() []string {
 	return members
 }
 
+// IsMarkerShape returns true if a given shape name is a marker shape,
+// otherwise returns false
+func (c *Config) IsMarkerShape(shapeName string) bool {
+	for _, markerShape := range c.MarkerShapes {
+		if markerShape == shapeName {
+			return true
+		}
+	}
+	return false
+}
+
 // New returns a new Config object given a supplied
 // path to a config file
 func New(

pkg/generate/code/set_sdk.go

@@ -1388,8 +1388,13 @@ func varEmptyConstructorK8sType(
 
 	switch shape.Type {
 	case "structure":
-		// f0 := &svcapitypes.BookData{}
-		out += fmt.Sprintf("%s%s := &%s{}\n", indent, varName, goType)
+		if r.Config().IsMarkerShape(shape.ShapeName) {
+			// f0 := []byte{}
+			out += fmt.Sprintf("%s%s := []byte{}\n", indent, varName)
+		} else {
+			// f0 := &svcapitypes.BookData{}
+			out += fmt.Sprintf("%s%s := &%s{}\n", indent, varName, goType)
+		}
 	case "list", "map":
 		// f0 := []*string{}
 		out += fmt.Sprintf("%s%s := %s{}\n", indent, varName, goType)

pkg/model/model.go

@@ -16,6 +16,7 @@ package model
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 
@@ -395,6 +396,11 @@ func (m *Model) IsShapeUsedInCRDs(shapeName string) bool {
 	return false
 }
 
+// IsMarkerShape return true if the supplied shape name is a marker shape
+func (m *Model) IsMarkerShape(shapeName string) bool {
+	return slices.Contains(m.cfg.MarkerShapes, shapeName)
+}
+
 // GetTypeDefs returns a slice of `TypeDef` pointers
 func (m *Model) GetTypeDefs() ([]*TypeDef, error) {
 	if m.typeDefs != nil {
@@ -471,6 +477,12 @@ func (m *Model) getShapeCleanGoType(shape *awssdkmodel.Shape) string {
 		// otherwise there is no DeepCopy support
 		return "*metav1.Time"
 	case "structure":
+		if len(shape.MemberRefs) == 0 {
+			if m.cfg.IsMarkerShape(shape.ShapeName) {
+				return "[]byte"
+			}
+			panic(fmt.Sprintf("structure %s has no fields, either configure it as a `marker_shape` or manually set the field type", shape.ShapeName))
+		}
 		// There are shapes that are called things like DBProxyStatus that are
 		// fields in a DBProxy CRD... we need to ensure the type names don't
 		// conflict. Also, the name of the Go type in the generated code is