OSModifier: Add services and modules support in EMU API (#27)

<!-- Description: Please provide a summary of the changes and the
motivation behind them. -->

---
cherry picked commits from the approved pr:
microsoft/azurelinux#11153

What does the PR accomplish, why was it needed?

the goal is to add services and modules support in EMU API to support
trident.

- Create a modulelist type to avoid code duplication
- Add functions to update services and modules in osmodifier

### **Checklist**
- [x] Tests added/updated
- [x] Documentation updated (if needed)
- [x] Code conforms to style guidelines

toolkit/tools/imagecustomizerapi/module.go

@@ -14,6 +14,27 @@ type Module struct {
 	Options  map[string]string `yaml:"options"`
 }
 
+type ModuleList struct {
+	Modules []Module `yaml:"modules"`
+}
+
+func (m *ModuleList) IsValid() error {
+	moduleMap := make(map[string]int)
+	for i, module := range m.Modules {
+		// Check if module is duplicated to avoid conflicts with modules potentially having different LoadMode
+		if _, exists := moduleMap[module.Name]; exists {
+			return fmt.Errorf("duplicate module found: %s at index %d", module.Name, i)
+		}
+		moduleMap[module.Name] = i
+		err := module.IsValid()
+		if err != nil {
+			return fmt.Errorf("invalid modules item at index %d:\n%w", i, err)
+		}
+	}
+
+	return nil
+}
+
 func (m *Module) IsValid() error {
 	if err := validateModuleName(m.Name); err != nil {
 		return err

toolkit/tools/imagecustomizerapi/os.go

@@ -21,7 +21,7 @@ type OS struct {
 	AdditionalDirs      DirConfigList       `yaml:"additionalDirs"`
 	Users               []User              `yaml:"users"`
 	Services            Services            `yaml:"services"`
-	Modules             []Module            `yaml:"modules"`
+	Modules             ModuleList          `yaml:"modules"`
 	Overlays            *[]Overlay          `yaml:"overlays"`
 }
 
@@ -69,17 +69,8 @@ func (s *OS) IsValid() error {
 		return err
 	}
 
-	moduleMap := make(map[string]int)
-	for i, module := range s.Modules {
-		// Check if module is duplicated to avoid conflicts with modules potentially having different LoadMode
-		if _, exists := moduleMap[module.Name]; exists {
-			return fmt.Errorf("duplicate module found: %s at index %d", module.Name, i)
-		}
-		moduleMap[module.Name] = i
-		err = module.IsValid()
-		if err != nil {
-			return fmt.Errorf("invalid modules item at index %d:\n%w", i, err)
-		}
+	if err := s.Modules.IsValid(); err != nil {
+		return err
 	}
 
 	if s.Overlays != nil {

toolkit/tools/imagecustomizerapi/os_test.go

@@ -133,9 +133,11 @@ func TestOSIsValidInvalidServices(t *testing.T) {
 
 func TestOSIsValidInvalidModule(t *testing.T) {
 	os := OS{
-		Modules: []Module{
-			{
-				Name: "",
+		Modules: ModuleList{
+			Modules: []Module{
+				{
+					Name: "",
+				},
 			},
 		},
 	}
@@ -147,12 +149,14 @@ func TestOSIsValidInvalidModule(t *testing.T) {
 
 func TestOSIsValidModuleDuplicateName(t *testing.T) {
 	os := OS{
-		Modules: []Module{
-			{
-				Name: "nbd",
-			},
-			{
-				Name: "nbd",
+		Modules: ModuleList{
+			Modules: []Module{
+				{
+					Name: "nbd",
+				},
+				{
+					Name: "nbd",
+				},
 			},
 		},
 	}

toolkit/tools/osmodifierapi/os.go

@@ -18,6 +18,8 @@ type OS struct {
 	Users             []imagecustomizerapi.User            `yaml:"users"`
 	Overlays          *[]Overlay                           `yaml:"overlays"`
 	KernelCommandLine imagecustomizerapi.KernelCommandLine `yaml:"kernelCommandLine"`
+	Services          imagecustomizerapi.Services          `yaml:"services"`
+	Modules           imagecustomizerapi.ModuleList        `yaml:"modules"`
 }
 
 func (s *OS) IsValid() error {
@@ -66,9 +68,12 @@ func (s *OS) IsValid() error {
 		}
 	}
 
-	err = s.KernelCommandLine.IsValid()
-	if err != nil {
-		return fmt.Errorf("invalid kernelCommandLine:\n%w", err)
+	if err := s.Services.IsValid(); err != nil {
+		return err
+	}
+
+	if err := s.Modules.IsValid(); err != nil {
+		return err
 	}
 
 	return nil

toolkit/tools/pkg/imagecustomizerlib/customizeos.go

@@ -49,12 +49,12 @@ func doOsCustomizations(buildDir string, baseConfigPath string, config *imagecus
 		return err
 	}
 
-	err = enableOrDisableServices(config.OS.Services, imageChroot)
+	err = EnableOrDisableServices(config.OS.Services, imageChroot)
 	if err != nil {
 		return err
 	}
 
-	err = loadOrDisableModules(config.OS.Modules, imageChroot.RootDir())
+	err = LoadOrDisableModules(config.OS.Modules, imageChroot.RootDir())
 	if err != nil {
 		return err
 	}

toolkit/tools/pkg/imagecustomizerlib/customizeservices.go

@@ -13,7 +13,7 @@ import (
 	"github.com/microsoft/azurelinux/toolkit/tools/internal/systemd"
 )
 
-func enableOrDisableServices(services imagecustomizerapi.Services, imageChroot safechroot.ChrootInterface) error {
+func EnableOrDisableServices(services imagecustomizerapi.Services, imageChroot safechroot.ChrootInterface) error {
 	var err error
 
 	// Handle enabling services

toolkit/tools/pkg/imagecustomizerlib/kernelmoduleutils.go

@@ -27,7 +27,7 @@ const (
 	moduleOptionsPath  = modprobeConfigDir + "/" + moduleOptionsFileName
 )
 
-func loadOrDisableModules(modules []imagecustomizerapi.Module, rootDir string) error {
+func LoadOrDisableModules(modules imagecustomizerapi.ModuleList, rootDir string) error {
 	var err error
 	var modulesToLoad []string
 	var modulesToDisable []string
@@ -36,7 +36,7 @@ func loadOrDisableModules(modules []imagecustomizerapi.Module, rootDir string) e
 	moduleLoadFilePath := filepath.Join(rootDir, moduleLoadPath)
 	moduleOptionsFilePath := filepath.Join(rootDir, moduleOptionsPath)
 
-	for i, module := range modules {
+	for i, module := range modules.Modules {
 		switch module.LoadMode {
 		case imagecustomizerapi.ModuleLoadModeAlways:
 			// If a module is disabled, remove it. Add the module to modules-load.d/. Write options if provided.

toolkit/tools/pkg/imagecustomizerlib/kernelmoduleutils_test.go

@@ -16,24 +16,26 @@ import (
 
 func TestLoadOrDisableModules(t *testing.T) {
 	rootDir := filepath.Join(tmpDir, "TestLoadOrDisableModules")
-	modules := []imagecustomizerapi.Module{
-		{
-			Name:     "module1",
-			LoadMode: imagecustomizerapi.ModuleLoadModeAlways,
-			Options:  map[string]string{"option1": "value1"},
-		},
-		{
-			Name:     "module2",
-			LoadMode: imagecustomizerapi.ModuleLoadModeDisable,
-		},
-		{
-			Name:     "module3",
-			LoadMode: imagecustomizerapi.ModuleLoadModeAuto,
-			Options:  map[string]string{"option3_1": "value3_1", "option3_2": "value3_2"},
+	modules := imagecustomizerapi.ModuleList{
+		Modules: []imagecustomizerapi.Module{
+			{
+				Name:     "module1",
+				LoadMode: imagecustomizerapi.ModuleLoadModeAlways,
+				Options:  map[string]string{"option1": "value1"},
+			},
+			{
+				Name:     "module2",
+				LoadMode: imagecustomizerapi.ModuleLoadModeDisable,
+			},
+			{
+				Name:     "module3",
+				LoadMode: imagecustomizerapi.ModuleLoadModeAuto,
+				Options:  map[string]string{"option3_1": "value3_1", "option3_2": "value3_2"},
+			},
 		},
 	}
 
-	err := loadOrDisableModules(modules, rootDir)
+	err := LoadOrDisableModules(modules, rootDir)
 	assert.NoError(t, err)
 
 	moduleLoadFilePath := filepath.Join(rootDir, moduleLoadPath)
@@ -61,29 +63,33 @@ func TestLoadOrDisableModules(t *testing.T) {
 	assert.Contains(t, string(moduleOptionsContent), "option3_2=value3_2")
 
 	// Test add options for module2 which was disabled
-	modules = []imagecustomizerapi.Module{
-		{
-			Name:    "module2",
-			Options: map[string]string{"option2": "value2"},
+	modules = imagecustomizerapi.ModuleList{
+		Modules: []imagecustomizerapi.Module{
+			{
+				Name:    "module2",
+				Options: map[string]string{"option2": "value2"},
+			},
 		},
 	}
 
-	err = loadOrDisableModules(modules, rootDir)
+	err = LoadOrDisableModules(modules, rootDir)
 	assert.Contains(t, err.Error(), "cannot add options for disabled module (module2)")
 
 	// Test updating module2's loadmode and module3's option
-	modules = []imagecustomizerapi.Module{
-		{
-			Name:     "module2",
-			LoadMode: imagecustomizerapi.ModuleLoadModeAuto,
-			Options:  map[string]string{"option2": "value2"},
-		},
-		{
-			Name:    "module3",
-			Options: map[string]string{"option3_1": "new_value3_1", "option3_3": "new_value3_3"},
+	modules = imagecustomizerapi.ModuleList{
+		Modules: []imagecustomizerapi.Module{
+			{
+				Name:     "module2",
+				LoadMode: imagecustomizerapi.ModuleLoadModeAuto,
+				Options:  map[string]string{"option2": "value2"},
+			},
+			{
+				Name:    "module3",
+				Options: map[string]string{"option3_1": "new_value3_1", "option3_3": "new_value3_3"},
+			},
 		},
 	}
-	err = loadOrDisableModules(modules, rootDir)
+	err = LoadOrDisableModules(modules, rootDir)
 	assert.NoError(t, err)
 
 	moduleDisableContent, _ = os.ReadFile(moduleDisableFilePath)
@@ -96,15 +102,17 @@ func TestLoadOrDisableModules(t *testing.T) {
 	assert.Contains(t, string(moduleOptionsContent), "option3_3=new_value3_3")
 
 	// Test case where a module was already set to load at boot
-	modules = []imagecustomizerapi.Module{
-		{
-			Name:     "module1",
-			LoadMode: imagecustomizerapi.ModuleLoadModeAlways,
-			Options:  map[string]string{"option1": "value1"},
+	modules = imagecustomizerapi.ModuleList{
+		Modules: []imagecustomizerapi.Module{
+			{
+				Name:     "module1",
+				LoadMode: imagecustomizerapi.ModuleLoadModeAlways,
+				Options:  map[string]string{"option1": "value1"},
+			},
 		},
 	}
 
-	err = loadOrDisableModules(modules, rootDir)
+	err = LoadOrDisableModules(modules, rootDir)
 	assert.NoError(t, err)
 
 	moduleLoadContent, _ = os.ReadFile(moduleLoadFilePath)

toolkit/tools/pkg/osmodifierlib/modifierutils.go

@@ -27,6 +27,16 @@ func doModifications(baseConfigPath string, osConfig *osmodifierapi.OS) error {
 		return err
 	}
 
+	err = imagecustomizerlib.EnableOrDisableServices(osConfig.Services, dummyChroot)
+	if err != nil {
+		return err
+	}
+
+	err = imagecustomizerlib.LoadOrDisableModules(osConfig.Modules, dummyChroot.RootDir())
+	if err != nil {
+		return err
+	}
+
 	if osConfig.Overlays != nil {
 		bootCustomizer, err := imagecustomizerlib.NewBootCustomizer(dummyChroot)
 		if err != nil {