func main()

in scripts/generate-gvks/main.go [39:159]
105 lines of code
17 McCabe index (conditional complexity)

func main() {
	flag.StringVar(&inputDir, "input-dir", "", "Input directory to read CRD listing.")
	flag.StringVar(&outputFile, "output-file", "", "Output file to write GVK -> reconciler type mapping.")
	flag.Parse()

	if inputDir == "" {
		fmt.Fprintf(os.Stderr, "error: invalid value for input directory: '%s'\n", "empty string")
		flag.PrintDefaults()
		os.Exit(1)
	}

	if outputFile == "" {
		fmt.Fprintf(os.Stderr, "error: invalid value for output file: '%s'\n", "empty string")
		flag.PrintDefaults()
		os.Exit(1)
	}

	crds := make([]apiextensions.CustomResourceDefinition, 0)
	err := filepath.WalkDir(inputDir, func(path string, info fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() || !strings.HasSuffix(path, ".yaml") {
			return nil
		}
		y, err := os.ReadFile(path)
		if err != nil {
			return fmt.Errorf("failed to read CRD file %s: %w", path, err)
		}
		var crd apiextensions.CustomResourceDefinition
		if err := yaml.Unmarshal(y, &crd); err != nil {
			return fmt.Errorf("error unmarshalling bytes into CRD: %w", err)
		}
		crds = append(crds, crd)
		return nil
	})
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to read CRDs: %v\n", err)
		os.Exit(1)
	}

	out := `// 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.

// Code generated by "scripts/generate-gvks" in "make manifests"; DO NOT EDIT.

package supportedgvks

import "k8s.io/apimachinery/pkg/runtime/schema"

type GVKMetadata struct {
	Labels map[string]string
}

var SupportedGVKs = map[schema.GroupVersionKind]GVKMetadata{`

	for _, crd := range crds {
		for _, version := range crd.Spec.Versions {
			gvk := schema.GroupVersionKind{
				Group:   crd.Spec.Group,
				Kind:    crd.Spec.Names.Kind,
				Version: version.Name,
			}

			gvkEntry := `
	{
		Group:   "%s",
		Version: "%s",
		Kind:    "%s",
	}: {
		Labels: map[string]string{`
			// Iterate over the labels in sorted order to produce deterministic output.
			keys := make([]string, 0)
			for k, _ := range crd.Labels {
				keys = append(keys, k)
			}
			sort.Strings(keys)
			for _, k := range keys {
				labelEntry := `
			"%s": "%s",`
				gvkEntry += fmt.Sprintf(labelEntry, k, crd.Labels[k])
			}
			gvkEntry += `
		},
	},`
			out += fmt.Sprintf(gvkEntry, gvk.Group, gvk.Version, gvk.Kind)
		}
	}

	out += `}`

	outFormatted, err := format.Source([]byte(out))
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error formatting output file: %s\n", err)
		os.Exit(1)
	}

	file, err := os.OpenFile(outputFile, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error opening output file: %s\n", err)
		os.Exit(1)
	}
	defer file.Close()

	_, err = file.Write(outFormatted)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error writing to output file: %s\n", err)
		os.Exit(1)
	}
}