feat: Implement immutable DMS command policy

- Added pre-run checks for greeter and setup commands to enforce policy restrictions
- Created cli-policy.default.json to define blocked commands and user messages for immutable environments.

core/cmd/dms/assets/cli-policy.default.json

@@ -0,0 +1,10 @@
+{
+  "policy_version": 1,
+  "blocked_commands": [
+    "greeter install",
+    "greeter enable",
+    "greeter sync",
+    "setup"
+  ],
+  "message": "This command is disabled on immutable/image-based systems. Use your distro-native workflow for system-level changes."
+}

core/cmd/dms/commands_greeter.go

@@ -24,9 +24,10 @@ var greeterCmd = &cobra.Command{
 }
 
 var greeterInstallCmd = &cobra.Command{
-	Use:   "install",
-	Short: "Install and configure DMS greeter",
-	Long:  "Install greetd and configure it to use DMS as the greeter interface",
+	Use:     "install",
+	Short:   "Install and configure DMS greeter",
+	Long:    "Install greetd and configure it to use DMS as the greeter interface",
+	PreRunE: requireMutableSystemCommand,
 	Run: func(cmd *cobra.Command, args []string) {
 		if err := installGreeter(); err != nil {
 			log.Fatalf("Error installing greeter: %v", err)
@@ -35,9 +36,10 @@ var greeterInstallCmd = &cobra.Command{
 }
 
 var greeterSyncCmd = &cobra.Command{
-	Use:   "sync",
-	Short: "Sync DMS theme and settings with greeter",
-	Long:  "Synchronize your current user's DMS theme, settings, and wallpaper configuration with the login greeter screen",
+	Use:     "sync",
+	Short:   "Sync DMS theme and settings with greeter",
+	Long:    "Synchronize your current user's DMS theme, settings, and wallpaper configuration with the login greeter screen",
+	PreRunE: requireMutableSystemCommand,
 	Run: func(cmd *cobra.Command, args []string) {
 		yes, _ := cmd.Flags().GetBool("yes")
 		auth, _ := cmd.Flags().GetBool("auth")
@@ -63,9 +65,10 @@ func init() {
 }
 
 var greeterEnableCmd = &cobra.Command{
-	Use:   "enable",
-	Short: "Enable DMS greeter in greetd config",
-	Long:  "Configure greetd to use DMS as the greeter",
+	Use:     "enable",
+	Short:   "Enable DMS greeter in greetd config",
+	Long:    "Configure greetd to use DMS as the greeter",
+	PreRunE: requireMutableSystemCommand,
 	Run: func(cmd *cobra.Command, args []string) {
 		if err := enableGreeter(); err != nil {
 			log.Fatalf("Error enabling greeter: %v", err)

core/cmd/dms/commands_setup.go

@@ -16,9 +16,10 @@ import (
 )
 
 var setupCmd = &cobra.Command{
-	Use:   "setup",
-	Short: "Deploy DMS configurations",
-	Long:  "Deploy compositor and terminal configurations with interactive prompts",
+	Use:               "setup",
+	Short:             "Deploy DMS configurations",
+	Long:              "Deploy compositor and terminal configurations with interactive prompts",
+	PersistentPreRunE: requireMutableSystemCommand,
 	Run: func(cmd *cobra.Command, args []string) {
 		if err := runSetup(); err != nil {
 			log.Fatalf("Error during setup: %v", err)

core/cmd/dms/immutable_policy.go

@@ -0,0 +1,271 @@
+package main
+
+import (
+	"bufio"
+	_ "embed"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/spf13/cobra"
+)
+
+const (
+	cliPolicyPackagedPath = "/usr/share/dms/cli-policy.json"
+	cliPolicyAdminPath    = "/etc/dms/cli-policy.json"
+)
+
+var (
+	immutablePolicyOnce sync.Once
+	immutablePolicy     immutableCommandPolicy
+	immutablePolicyErr  error
+)
+
+//go:embed assets/cli-policy.default.json
+var defaultCLIPolicyJSON []byte
+
+type immutableCommandPolicy struct {
+	ImmutableSystem bool
+	ImmutableReason string
+	BlockedCommands []string
+	Message         string
+}
+
+type cliPolicyFile struct {
+	PolicyVersion   int       `json:"policy_version"`
+	ImmutableSystem *bool     `json:"immutable_system"`
+	BlockedCommands *[]string `json:"blocked_commands"`
+	Message         *string   `json:"message"`
+}
+
+func normalizeCommandSpec(raw string) string {
+	normalized := strings.ToLower(strings.TrimSpace(raw))
+	normalized = strings.TrimPrefix(normalized, "dms ")
+	return strings.Join(strings.Fields(normalized), " ")
+}
+
+func normalizeBlockedCommands(raw []string) []string {
+	normalized := make([]string, 0, len(raw))
+	seen := make(map[string]bool)
+
+	for _, cmd := range raw {
+		spec := normalizeCommandSpec(cmd)
+		if spec == "" || seen[spec] {
+			continue
+		}
+		seen[spec] = true
+		normalized = append(normalized, spec)
+	}
+
+	return normalized
+}
+
+func commandBlockedByPolicy(commandPath string, blocked []string) bool {
+	normalizedPath := normalizeCommandSpec(commandPath)
+	if normalizedPath == "" {
+		return false
+	}
+
+	for _, entry := range blocked {
+		spec := normalizeCommandSpec(entry)
+		if spec == "" {
+			continue
+		}
+		if normalizedPath == spec || strings.HasPrefix(normalizedPath, spec+" ") {
+			return true
+		}
+	}
+
+	return false
+}
+
+func loadPolicyFile(path string) (*cliPolicyFile, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("failed to read %s: %w", path, err)
+	}
+
+	var policy cliPolicyFile
+	if err := json.Unmarshal(data, &policy); err != nil {
+		return nil, fmt.Errorf("failed to parse %s: %w", path, err)
+	}
+
+	return &policy, nil
+}
+
+func mergePolicyFile(base *immutableCommandPolicy, path string) error {
+	policyFile, err := loadPolicyFile(path)
+	if err != nil {
+		return err
+	}
+	if policyFile == nil {
+		return nil
+	}
+
+	if policyFile.ImmutableSystem != nil {
+		base.ImmutableSystem = *policyFile.ImmutableSystem
+	}
+	if policyFile.BlockedCommands != nil {
+		base.BlockedCommands = normalizeBlockedCommands(*policyFile.BlockedCommands)
+	}
+	if policyFile.Message != nil {
+		msg := strings.TrimSpace(*policyFile.Message)
+		if msg != "" {
+			base.Message = msg
+		}
+	}
+
+	return nil
+}
+
+func readOSReleaseMap(path string) map[string]string {
+	values := make(map[string]string)
+
+	file, err := os.Open(path)
+	if err != nil {
+		return values
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) != 2 {
+			continue
+		}
+		key := strings.ToUpper(strings.TrimSpace(parts[0]))
+		value := strings.Trim(strings.TrimSpace(parts[1]), "\"")
+		values[key] = strings.ToLower(value)
+	}
+
+	return values
+}
+
+func hasAnyToken(text string, tokens ...string) bool {
+	if text == "" {
+		return false
+	}
+	for _, token := range tokens {
+		if strings.Contains(text, token) {
+			return true
+		}
+	}
+	return false
+}
+
+func detectImmutableSystem() (bool, string) {
+	if _, err := os.Stat("/run/ostree-booted"); err == nil {
+		return true, "/run/ostree-booted is present"
+	}
+
+	osRelease := readOSReleaseMap("/etc/os-release")
+	if len(osRelease) == 0 {
+		return false, ""
+	}
+
+	id := osRelease["ID"]
+	idLike := osRelease["ID_LIKE"]
+	variantID := osRelease["VARIANT_ID"]
+	name := osRelease["NAME"]
+	prettyName := osRelease["PRETTY_NAME"]
+
+	immutableIDs := map[string]bool{
+		"bluefin":       true,
+		"bazzite":       true,
+		"silverblue":    true,
+		"kinoite":       true,
+		"sericea":       true,
+		"onyx":          true,
+		"aurora":        true,
+		"fedora-iot":    true,
+		"fedora-coreos": true,
+	}
+	if immutableIDs[id] {
+		return true, "os-release ID=" + id
+	}
+
+	markers := []string{"silverblue", "kinoite", "sericea", "onyx", "bazzite", "bluefin", "aurora", "ostree", "atomic"}
+	if hasAnyToken(variantID, markers...) {
+		return true, "os-release VARIANT_ID=" + variantID
+	}
+	if hasAnyToken(idLike, "ostree", "rpm-ostree") {
+		return true, "os-release ID_LIKE=" + idLike
+	}
+	if hasAnyToken(name, markers...) || hasAnyToken(prettyName, markers...) {
+		return true, "os-release identifies an atomic/ostree variant"
+	}
+
+	return false, ""
+}
+
+func getImmutablePolicy() (*immutableCommandPolicy, error) {
+	immutablePolicyOnce.Do(func() {
+		detectedImmutable, reason := detectImmutableSystem()
+		immutablePolicy = immutableCommandPolicy{
+			ImmutableSystem: detectedImmutable,
+			ImmutableReason: reason,
+			BlockedCommands: []string{"greeter install", "greeter enable", "greeter sync", "setup"},
+			Message:         "This command is disabled on immutable/image-based systems. Use your distro-native workflow for system-level changes.",
+		}
+
+		var defaultPolicy cliPolicyFile
+		if err := json.Unmarshal(defaultCLIPolicyJSON, &defaultPolicy); err != nil {
+			immutablePolicyErr = fmt.Errorf("failed to parse embedded default CLI policy: %w", err)
+			return
+		}
+		if defaultPolicy.BlockedCommands != nil {
+			immutablePolicy.BlockedCommands = normalizeBlockedCommands(*defaultPolicy.BlockedCommands)
+		}
+		if defaultPolicy.Message != nil {
+			msg := strings.TrimSpace(*defaultPolicy.Message)
+			if msg != "" {
+				immutablePolicy.Message = msg
+			}
+		}
+
+		if err := mergePolicyFile(&immutablePolicy, cliPolicyPackagedPath); err != nil {
+			immutablePolicyErr = err
+			return
+		}
+		if err := mergePolicyFile(&immutablePolicy, cliPolicyAdminPath); err != nil {
+			immutablePolicyErr = err
+			return
+		}
+	})
+
+	if immutablePolicyErr != nil {
+		return nil, immutablePolicyErr
+	}
+	return &immutablePolicy, nil
+}
+
+func requireMutableSystemCommand(cmd *cobra.Command, _ []string) error {
+	policy, err := getImmutablePolicy()
+	if err != nil {
+		return err
+	}
+	if !policy.ImmutableSystem {
+		return nil
+	}
+
+	commandPath := normalizeCommandSpec(cmd.CommandPath())
+	if !commandBlockedByPolicy(commandPath, policy.BlockedCommands) {
+		return nil
+	}
+
+	reason := ""
+	if policy.ImmutableReason != "" {
+		reason = "Detected immutable system: " + policy.ImmutableReason + "\n"
+	}
+
+	return fmt.Errorf("%s%s\nCommand: dms %s\nPolicy files:\n  %s\n  %s", reason, policy.Message, commandPath, cliPolicyPackagedPath, cliPolicyAdminPath)
+}

core/internal/server/network/detect_test.go

@@ -1,6 +1,7 @@
 package network
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -28,7 +29,13 @@ func TestDetectResult_HasNetworkdField(t *testing.T) {
 
 func TestDetectNetworkStack_Integration(t *testing.T) {
 	result, err := DetectNetworkStack()
+
+	if err != nil && strings.Contains(err.Error(), "connect system bus") {
+		t.Skipf("system D-Bus unavailable: %v", err)
+	}
+
 	assert.NoError(t, err)
-	assert.NotNil(t, result)
-	assert.NotEmpty(t, result.ChosenReason)
+	if assert.NotNil(t, result) {
+		assert.NotEmpty(t, result.ChosenReason)
+	}
 }