feat: add support for 'kustomize edit add configuration' command

kustomize/commands/edit/add/addconfiguration.go

@@ -0,0 +1,79 @@
+// Copyright 2025 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package add
+
+import (
+	"errors"
+	"log"
+	"slices"
+
+	"github.com/spf13/cobra"
+	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
+	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/util"
+	"sigs.k8s.io/kustomize/kyaml/filesys"
+)
+
+type addConfigurationOptions struct {
+	configurationFilePaths []string
+}
+
+// newCmdAddConfiguration adds the name of a file containing a configuration
+// to the kustomization file.
+func newCmdAddConfiguration(fSys filesys.FileSystem) *cobra.Command {
+	var o addConfigurationOptions
+	cmd := &cobra.Command{
+		Use:   "configuration",
+		Short: "Add the name of a file containing a configuration to the kustomization file",
+		Long: `Add the name of a file containing a configuration (e.g., a Kubernetes configuration resource) 
+to the kustomization file. Configurations are used to define custom transformer specifications 
+for CRDs and other resource types.`,
+		Example: `
+	# Adds a configuration file to the kustomization
+	kustomize edit add configuration <filepath>
+
+	# Adds multiple configuration files
+	kustomize edit add configuration <filepath1>,<filepath2>`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(fSys, args)
+			if err != nil {
+				return err
+			}
+			return o.RunAddConfiguration(fSys)
+		},
+	}
+	return cmd
+}
+
+// Validate validates add configuration command.
+func (o *addConfigurationOptions) Validate(fSys filesys.FileSystem, args []string) error {
+	if len(args) == 0 {
+		return errors.New("must specify a yaml file which contains a configuration resource")
+	}
+	var err error
+	o.configurationFilePaths, err = util.GlobPatterns(fSys, args)
+	return err
+}
+
+// RunAddConfiguration runs add configuration command (do real work).
+func (o *addConfigurationOptions) RunAddConfiguration(fSys filesys.FileSystem) error {
+	if len(o.configurationFilePaths) == 0 {
+		return nil
+	}
+	mf, err := kustfile.NewKustomizationFile(fSys)
+	if err != nil {
+		return err
+	}
+	m, err := mf.Read()
+	if err != nil {
+		return err
+	}
+	for _, c := range o.configurationFilePaths {
+		if slices.Contains(m.Configurations, c) {
+			log.Printf("configuration %s already in kustomization file", c)
+			continue
+		}
+		m.Configurations = append(m.Configurations, c)
+	}
+	return mf.Write(m)
+}

kustomize/commands/edit/add/addconfiguration_test.go

@@ -0,0 +1,92 @@
+// Copyright 2025 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package add
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	testutils_test "sigs.k8s.io/kustomize/kustomize/v5/commands/internal/testutils"
+	"sigs.k8s.io/kustomize/kyaml/filesys"
+)
+
+func TestAddConfiguration(t *testing.T) {
+	fSys := filesys.MakeEmptyDirInMemory()
+	testutils_test.WriteTestKustomization(fSys)
+
+	cmd := newCmdAddConfiguration(fSys)
+
+	if cmd == nil {
+		t.Fatal("Expected cmd to not be nil")
+	}
+
+	if cmd.Use != "configuration" {
+		t.Fatalf("Expected Use to be 'configuration', got '%s'", cmd.Use)
+	}
+
+	if cmd.Short == "" {
+		t.Fatal("Expected Short to not be empty")
+	}
+}
+
+func TestAddConfigurationHappyPath(t *testing.T) {
+	fSys := filesys.MakeEmptyDirInMemory()
+	err := fSys.WriteFile("config1.yaml", []byte("apiVersion: v1\nkind: Config"))
+	require.NoError(t, err)
+	err = fSys.WriteFile("config2.yaml", []byte("apiVersion: v1\nkind: Config"))
+	require.NoError(t, err)
+	testutils_test.WriteTestKustomization(fSys)
+
+	cmd := newCmdAddConfiguration(fSys)
+	args := []string{"config1.yaml", "config2.yaml"}
+	require.NoError(t, cmd.RunE(cmd, args))
+
+	content, err := testutils_test.ReadTestKustomization(fSys)
+	require.NoError(t, err)
+	assert.Contains(t, string(content), "config1.yaml")
+	assert.Contains(t, string(content), "config2.yaml")
+}
+
+func TestAddConfigurationDuplicate(t *testing.T) {
+	fSys := filesys.MakeEmptyDirInMemory()
+	err := fSys.WriteFile("config.yaml", []byte("apiVersion: v1\nkind: Config"))
+	require.NoError(t, err)
+	testutils_test.WriteTestKustomization(fSys)
+
+	cmd := newCmdAddConfiguration(fSys)
+
+	// First addition
+	args := []string{"config.yaml"}
+	require.NoError(t, cmd.RunE(cmd, args))
+
+	content, err := testutils_test.ReadTestKustomization(fSys)
+	require.NoError(t, err)
+	assert.Contains(t, string(content), "config.yaml")
+
+	// Second addition (should skip duplicate)
+	require.NoError(t, cmd.RunE(cmd, args))
+
+	content, err = testutils_test.ReadTestKustomization(fSys)
+	require.NoError(t, err)
+
+	// Count occurrences - should only appear once
+	count := 0
+	data := string(content)
+	for i := 0; i < len(data); {
+		if idx := len(data[i:]); idx > 0 {
+			if len(data) >= i+11 {
+				if data[i:i+11] == "config.yaml" {
+					count++
+					i += 11
+				} else {
+					i++
+				}
+			} else {
+				break
+			}
+		}
+	}
+	assert.Equal(t, 1, count, "config.yaml should appear exactly once")
+}

kustomize/commands/edit/add/all.go

@@ -47,6 +47,12 @@ func NewCmdAdd(
 
 	# Adds a transformer configuration to the kustomization
 	kustomize edit add transformer <filepath>
+
+	# Adds a configuration file to the kustomization
+	kustomize edit add configuration <filepath>
+
+	# Adds a generator configuration to the kustomization
+	kustomize edit add generator <filepath>
 `,
 		Args: cobra.MinimumNArgs(1),
 	}
@@ -61,6 +67,7 @@ func NewCmdAdd(
 		newCmdAddLabel(fSys, ldr.Validator().MakeLabelValidator()),
 		newCmdAddAnnotation(fSys, ldr.Validator().MakeAnnotationValidator()),
 		newCmdAddTransformer(fSys),
+		newCmdAddConfiguration(fSys),
 		newCmdAddGenerator(fSys),
 	)
 	return c