✨re-scaffold the project with a new command

pkg/cli/alpha.go

@@ -21,6 +21,7 @@ import (
 	"strings"
 
 	"github.com/spf13/cobra"
+	"sigs.k8s.io/kubebuilder/v3/pkg/cli/alpha"
 )
 
 const (
@@ -29,6 +30,7 @@ const (
 
 var alphaCommands = []*cobra.Command{
 	newAlphaCommand(),
+	alpha.NewScaffoldCommand(),
 }
 
 func newAlphaCommand() *cobra.Command {

pkg/cli/alpha/generate.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+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 alpha
+
+import (
+	"log"
+
+	"github.com/spf13/cobra"
+	"sigs.k8s.io/kubebuilder/v3/pkg/rescaffold"
+)
+
+// NewScaffoldCommand return a new scaffold command
+func NewScaffoldCommand() *cobra.Command {
+	opts := rescaffold.MigrateOptions{}
+	scaffoldCmd := &cobra.Command{
+		Use:   "generate",
+		Short: "Re-scaffold an existing Kuberbuilder project",
+		Long: `It's an experimental feature that has the purpose of re-scaffolding the whole project from the scratch 
+using the current version of KubeBuilder binary available.
+# make sure the PROJECT file is in the 'input-dir' argument, the default is the current directory.
+$ kubebuilder alpha generate --input-dir="./test" --output-dir="./my-output"
+Then we will re-scaffold the project by Kubebuilder in the directory specified by 'output-dir'.
+		`,
+		PreRunE: func(cmd *cobra.Command, _ []string) error {
+			return opts.Validate()
+		},
+		Run: func(cmd *cobra.Command, args []string) {
+			if err := opts.Rescaffold(); err != nil {
+				log.Fatalf("Failed to rescaffold %s", err)
+			}
+		},
+	}
+	scaffoldCmd.Flags().StringVar(&opts.InputDir, "input-dir", "",
+		"path to a Kubebuilder project file if not in the current working directory")
+	scaffoldCmd.Flags().StringVar(&opts.OutputDir, "output-dir", "",
+		"path to output the scaffolding. defaults a directory in the current working directory")
+
+	return scaffoldCmd
+}

pkg/rescaffold/migrate.go

@@ -0,0 +1,107 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+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 rescaffold
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+
+	"github.com/spf13/afero"
+	"sigs.k8s.io/kubebuilder/v3/pkg/config/store"
+	"sigs.k8s.io/kubebuilder/v3/pkg/config/store/yaml"
+	"sigs.k8s.io/kubebuilder/v3/pkg/machinery"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugin/util"
+)
+
+type MigrateOptions struct {
+	InputDir  string
+	OutputDir string
+}
+
+const DefaultOutputDir = "output-dir"
+
+func (opts *MigrateOptions) Rescaffold() error {
+	config := yaml.New(machinery.Filesystem{FS: afero.NewOsFs()})
+	if err := config.LoadFrom(opts.InputDir); err != nil {
+		log.Fatal(err)
+	}
+	// create output directory
+	// nolint: gosec
+	if err := os.MkdirAll(opts.OutputDir, 0755); err != nil {
+		log.Fatal(err)
+	}
+	// use the new directory to set up the new project
+	if err := os.Chdir(opts.OutputDir); err != nil {
+		log.Fatal(err)
+	}
+	// init project with plugins
+	if err := kubebuilderInit(config); err != nil {
+		log.Fatal(err)
+	}
+	return nil
+}
+
+func (opts *MigrateOptions) Validate() error {
+	cwd, err := os.Getwd()
+	if err != nil {
+		log.Fatal(err)
+	}
+	// get PROJECT path from command args
+	inputPath, err := getInputPath(cwd, opts.InputDir)
+	if err != nil {
+		log.Fatal(err)
+	}
+	opts.InputDir = inputPath
+	// get output path from command args
+	opts.OutputDir, err = getOutputPath(cwd, opts.OutputDir)
+	if err != nil {
+		log.Fatal(err)
+	}
+	// check whether the kubebuilder binary is accessible
+	_, err = exec.LookPath("kubebuilder")
+	return err
+}
+
+func getInputPath(currentWorkingDirectory string, inputPath string) (string, error) {
+	if inputPath == "" {
+		inputPath = currentWorkingDirectory
+	}
+	projectPath := fmt.Sprintf("%s/%s", inputPath, yaml.DefaultPath)
+	if _, err := os.Stat(projectPath); os.IsNotExist(err) {
+		return "", fmt.Errorf("PROJECT path: %s does not exist. %v", projectPath, err)
+	}
+	return projectPath, nil
+}
+
+func getOutputPath(currentWorkingDirectory, outputPath string) (string, error) {
+	if outputPath == "" {
+		outputPath = fmt.Sprintf("%s/%s", currentWorkingDirectory, DefaultOutputDir)
+	}
+	_, err := os.Stat(outputPath)
+	if err == nil {
+		return "", fmt.Errorf("Output path: %s already exists. %v", outputPath, err)
+	}
+	if os.IsNotExist(err) {
+		return outputPath, nil
+	}
+	return "", err
+}
+
+func kubebuilderInit(_ store.Store) error {
+	var args []string
+	args = append(args, "init")
+	return util.RunCmd("kubebuilder init", "kubebuilder", args...)
+}