crd-tools: add command to remove descriptions

This is super-handy for diffing CRDs

Author: justinsb

scripts/crd-tools/cmd/removedescriptions/removedescriptions.go

@@ -0,0 +1,105 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package removedescriptions
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/pkg/objectvisitor"
+	"github.com/spf13/cobra"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+)
+
+func AddCommand(parent *cobra.Command) {
+	var opt Options
+	cmd := &cobra.Command{
+		Use:   "remove-descriptions",
+		Short: "Remove descriptions in objects, for easier schema-only comparison.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return Run(cmd.Context(), opt)
+		},
+	}
+	cmd.Flags().StringVar(&opt.Dir, "dir", "", "Directory to process")
+	parent.AddCommand(cmd)
+}
+
+type Options struct {
+	Dir string
+}
+
+func (o *Options) Validate() error {
+	return nil
+}
+
+func (o *Options) InitDefaults() {
+	o.Dir = ""
+}
+
+type visitor struct {
+	errors []error
+}
+
+func (v *visitor) VisitObject(crd *unstructured.Unstructured) error {
+	v.visitMap(crd.Object)
+	return errors.Join(v.errors...)
+}
+
+func (v *visitor) visitMap(m map[string]any) map[string]any {
+	delete(m, "description")
+	for k, val := range m {
+		m[k] = v.visitAny(val)
+	}
+	return m
+}
+
+func (v *visitor) visitSlice(s []any) []any {
+	for i, val := range s {
+		s[i] = v.visitAny(val)
+	}
+	return s
+}
+
+func (v *visitor) visitAny(val any) any {
+	switch val := val.(type) {
+	case map[string]any:
+		return v.visitMap(val)
+	case []any:
+		return v.visitSlice(val)
+	case string:
+		return val
+	case bool, int32, int64, float32, float64:
+		return val
+	case nil:
+		return val
+	default:
+		v.errors = append(v.errors, fmt.Errorf("unexpected type %T", val))
+		return val
+	}
+}
+
+func Run(ctx context.Context, options Options) error {
+	if err := options.Validate(); err != nil {
+		return err
+	}
+
+	visitor := &visitor{}
+	if options.Dir != "" {
+		return objectvisitor.VisitObjectsInDirectory(ctx, options.Dir, visitor)
+	} else {
+		return objectvisitor.VisitObjectsFromStdin(ctx, visitor)
+	}
+}

scripts/crd-tools/main.go

@@ -25,6 +25,7 @@ import (
 	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/cmd/deleteannotation"
 	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/cmd/deletefield"
 	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/cmd/reflowdescriptions"
+	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/cmd/removedescriptions"
 	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/cmd/setannotation"
 	"github.com/GoogleCloudPlatform/k8s-config-connector/scripts/crd-tools/cmd/setfield"
 	"github.com/spf13/cobra"
@@ -46,6 +47,7 @@ func run(ctx context.Context) error {
 	deleteannotation.AddCommand(rootCmd)
 	deletefield.AddCommand(rootCmd)
 	reflowdescriptions.AddCommand(rootCmd)
+	removedescriptions.AddCommand(rootCmd)
 	setannotation.AddCommand(rootCmd)
 	setfield.AddCommand(rootCmd)
 

scripts/crd-tools/pkg/objectvisitor/objectvisitor.go

@@ -18,6 +18,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
 	"io/fs"
 	"os"
 	"path/filepath"
@@ -56,12 +57,41 @@ func VisitObjectsInDirectory(ctx context.Context, dir string, visitor Visitor) e
 	return nil
 }
 
+func VisitObjectsFromStdin(ctx context.Context, visitor Visitor) error {
+	b, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		return fmt.Errorf("reading from stdin: %w", err)
+	}
+	out, err := processBytes(ctx, b, visitor)
+	if err != nil {
+		return fmt.Errorf("processing stdin: %w", err)
+	}
+
+	if _, err := os.Stdout.Write(out); err != nil {
+		return fmt.Errorf("error writing to stdout: %w", err)
+	}
+
+	return nil
+}
+
 func processFile(ctx context.Context, p string, visitor Visitor) error {
 	b, err := os.ReadFile(p)
 	if err != nil {
 		return fmt.Errorf("error reading file %q: %w", p, err)
 	}
 
+	out, err := processBytes(ctx, b, visitor)
+	if err != nil {
+		return fmt.Errorf("processing file %q: %w", p, err)
+	}
+
+	if err := os.WriteFile(p, out, 0644); err != nil {
+		return fmt.Errorf("error writing file %q: %w", p, err)
+	}
+	return nil
+}
+
+func processBytes(ctx context.Context, b []byte, visitor Visitor) ([]byte, error) {
 	var out bytes.Buffer
 
 	// We preserve the yaml header (copyright, typically)
@@ -76,38 +106,34 @@ func processFile(ctx context.Context, p string, visitor Visitor) error {
 
 	yamls, err := kccyaml.SplitYAML(b)
 	if err != nil {
-		return fmt.Errorf("error splitting bytes into YAMLs: %w", err)
+		return nil, fmt.Errorf("error splitting bytes into YAMLs: %w", err)
 	}
 	objects := make([]*unstructured.Unstructured, 0)
 	for _, y := range yamls {
 		crd := &unstructured.Unstructured{}
 		if err := yaml.Unmarshal(y, crd); err != nil {
-			return fmt.Errorf("error unmarshalling bytes to object: %w", err)
+			return nil, fmt.Errorf("error unmarshalling bytes to object: %w", err)
 		}
 		objects = append(objects, crd)
 	}
 
 	for _, obj := range objects {
 		if err := visitor.VisitObject(obj); err != nil {
-			return err
+			return nil, err
 		}
 	}
 
 	for i, obj := range objects {
 		b, err := yaml.Marshal(obj)
 		if err != nil {
-			return fmt.Errorf("error marshalling object to bytes: %w", err)
+			return nil, fmt.Errorf("error marshalling object to bytes: %w", err)
 		}
 		out.Write(b)
 		if i != 0 {
 			out.WriteString("\n---\n")
 		}
 	}
-
-	if err := os.WriteFile(p, out.Bytes(), 0644); err != nil {
-		return fmt.Errorf("error writing file %q: %w", p, err)
-	}
-	return nil
+	return out.Bytes(), nil
 }
 
 func PtrTo[T any](t T) *T {