Merge pull request #4005 from adamkpickering/3953-refactor-rdctl-getR…

…DPath

Refactor `rdctl` code that gets path to main Rancher Desktop executable

src/go/rdctl/cmd/start.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
-	"path/filepath"
 	"runtime"
 	"strings"
 
@@ -83,23 +82,10 @@ func doStartCommand(cmd *cobra.Command) error {
 	if err != nil {
 		return err
 	}
-	if applicationPath == "" {
-		pathLookupFuncs := map[string]func(rdctlPath string) string{
-			"windows": utils.GetWindowsRDPath,
-			"linux":   getLinuxRDPath,
-			"darwin":  utils.GetDarwinRDPath,
-		}
-		getPathFunc, ok := pathLookupFuncs[runtime.GOOS]
-		if !ok {
-			return fmt.Errorf("don't know how to find the path to Rancher Desktop on OS %s", runtime.GOOS)
-		}
-		rdctlPath, err := os.Executable()
+	if !cmd.Flags().Changed("path") {
+		applicationPath, err = utils.GetRDPath()
 		if err != nil {
-			rdctlPath = ""
-		}
-		applicationPath = getPathFunc(rdctlPath)
-		if applicationPath == "" {
-			return fmt.Errorf("could not locate main Rancher Desktop executable; please retry with the --path option")
+			return fmt.Errorf("failed to locate main Rancher Desktop executable: %w\nplease retry with the --path option", err)
 		}
 	}
 	return launchApp(applicationPath, commandLineArgs)
@@ -128,13 +114,3 @@ func launchApp(applicationPath string, commandLineArgs []string) error {
 	cmd.Stderr = os.Stderr
 	return cmd.Start()
 }
-func getLinuxRDPath(rdctlPath string) string {
-	if rdctlPath != "" {
-		normalParentPath := utils.MoveToParent(rdctlPath, 5)
-		candidatePath := utils.CheckExistence(filepath.Join(normalParentPath, "rancher-desktop"), 0o111)
-		if candidatePath != "" {
-			return candidatePath
-		}
-	}
-	return utils.CheckExistence("/opt/rancher-desktop/rancher-desktop", 0o111)
-}

src/go/rdctl/pkg/autostart/autostart_darwin.go

@@ -84,14 +84,9 @@ func EnsureAutostart(autostartDesired bool) error {
 }
 
 func getDesiredLaunchAgentFileContents() ([]byte, error) {
-	// get path to main Rancher Desktop executable
-	rdctlPath, err := os.Executable()
+	rancherDesktopPath, err := utils.GetRDPath()
 	if err != nil {
-		return []byte{}, fmt.Errorf("failed to get path to rdctl: %w", err)
-	}
-	rancherDesktopPath := utils.GetDarwinRDPath(rdctlPath)
-	if rancherDesktopPath == "" {
-		return []byte{}, errors.New("failed to get path to main Rancher Desktop executable")
+		return []byte{}, fmt.Errorf("failed to get path to main Rancher Desktop executable: %w", err)
 	}
 
 	// get desired contents of LaunchAgent file

src/go/rdctl/pkg/autostart/autostart_windows.go

@@ -3,7 +3,6 @@ package autostart
 import (
 	"errors"
 	"fmt"
-	"os"
 
 	"github.com/rancher-sandbox/rancher-desktop/src/go/rdctl/pkg/utils"
 	"golang.org/x/sys/windows/registry"
@@ -26,13 +25,9 @@ func EnsureAutostart(autostartDesired bool) error {
 	defer autostartKey.Close()
 
 	if autostartDesired {
-		rdctlPath, err := os.Executable()
+		rancherDesktopPath, err := utils.GetRDPath()
 		if err != nil {
-			return fmt.Errorf("failed to get path to rdctl: %w", err)
-		}
-		rancherDesktopPath := utils.GetWindowsRDPath(rdctlPath)
-		if rancherDesktopPath == "" {
-			return errors.New("failed to get path to Rancher Desktop.exe")
+			return fmt.Errorf("failed to get path to Rancher Desktop.exe: %w", err)
 		}
 		err = autostartKey.SetStringValue(nameValue, rancherDesktopPath)
 		if err != nil {

src/go/rdctl/pkg/utils/utils.go

@@ -1,91 +1,14 @@
 package utils
 
 import (
-	"io/fs"
-	"os"
 	"path/filepath"
-
-	"github.com/rancher-sandbox/rancher-desktop/src/go/rdctl/pkg/directories"
 )
 
-// Get the parent (or grandparent, or great-grandparent...) directory of fullPath.
-// numberTimes is the number of steps to ascend in the directory hierarchy.
-func MoveToParent(fullPath string, numberTimes int) string {
+// Get the steps-th parent directory of fullPath.
+func getParentDir(fullPath string, steps int) string {
 	fullPath = filepath.Clean(fullPath)
-	for ; numberTimes > 0; numberTimes-- {
+	for ; steps > 0; steps-- {
 		fullPath = filepath.Dir(fullPath)
 	}
 	return fullPath
 }
-
-/**
- * Verify the path exists. For Linux pass in mode bits to guarantee the file is executable (for at least one
- * category of user). Note that on macOS the candidate is a directory, so never pass in mode bits.
- * And mode bits don't make sense on Windows.
- */
-func CheckExistence(candidatePath string, modeBits fs.FileMode) string {
-	stat, err := os.Stat(candidatePath)
-	if err != nil {
-		return ""
-	}
-	if modeBits != 0 && (!stat.Mode().IsRegular() || stat.Mode().Perm()&modeBits == 0) {
-		// The modeBits check is only for executability -- we only care if at least one of the three
-		// `x` mode bits is on. So this check isn't used for a general permission-mode-bit check.
-		return ""
-	}
-	return candidatePath
-}
-
-// Returns the absolute path to the Rancher Desktop executable.
-// Returns an empty string if the executable was not found.
-func GetWindowsRDPath(rdctlPath string) string {
-	if rdctlPath != "" {
-		normalParentPath := MoveToParent(rdctlPath, 5)
-		candidatePath := CheckExistence(filepath.Join(normalParentPath, "Rancher Desktop.exe"), 0)
-		if candidatePath != "" {
-			return candidatePath
-		}
-	}
-	homedir, err := os.UserHomeDir()
-	if err != nil {
-		homedir = ""
-	}
-	dataPaths := []string{}
-	// %LOCALAPPDATA%
-	dir, err := directories.GetLocalAppDataDirectory()
-	if err == nil {
-		dataPaths = append(dataPaths, dir)
-	}
-	// %APPDATA%
-	dir, err = directories.GetRoamingAppDataDirectory()
-	if err == nil {
-		dataPaths = append(dataPaths, dir)
-	}
-	// Add these two paths if the above two fail to find where the program was installed
-	dataPaths = append(
-		dataPaths,
-		filepath.Join(homedir, "AppData", "Local"),
-		filepath.Join(homedir, "AppData", "Roaming"),
-	)
-	for _, dataDir := range dataPaths {
-		candidatePath := CheckExistence(filepath.Join(dataDir, "Programs", "Rancher Desktop", "Rancher Desktop.exe"), 0)
-		if candidatePath != "" {
-			return candidatePath
-		}
-	}
-	return ""
-}
-
-func GetDarwinRDPath(rdctlPath string) string {
-	if rdctlPath != "" {
-		// we're at .../Applications/R D.app (could have a different name)/Contents/Resources/resources/darwin/bin
-		// and want to move to the "R D.app" part
-		RDAppParentPath := MoveToParent(rdctlPath, 6)
-		if CheckExistence(filepath.Join(RDAppParentPath, "Contents", "MacOS", "Rancher Desktop"), 0o111) != "" {
-			return RDAppParentPath
-		}
-	}
-	// This fallback is mostly for running `npm run dev` and using the installed app because there is no app
-	// that rdctl would launch directly in dev mode.
-	return CheckExistence(filepath.Join("/Applications", "Rancher Desktop.app"), 0)
-}

src/go/rdctl/pkg/utils/utils_darwin.go

@@ -0,0 +1,46 @@
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// Returns the absolute path to the Rancher Desktop executable.
+// Returns an empty string if the executable was not found.
+func GetRDPath() (string, error) {
+	rdctlSymlinkPath, err := os.Executable()
+	if err != nil {
+		return "", fmt.Errorf("failed to get path to rdctl: %w", err)
+	}
+	rdctlPath, err := filepath.EvalSymlinks(rdctlSymlinkPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve %q: %w", rdctlSymlinkPath, err)
+	}
+
+	// we're at .../Applications/R D.app (could have a different name)/Contents/Resources/resources/darwin/bin/rdctl
+	// and want to move to the "R D.app" part
+	RDAppParentPath := getParentDir(rdctlPath, 6)
+	executablePath := filepath.Join(RDAppParentPath, "Contents", "MacOS", "Rancher Desktop")
+	usable, err := checkUsableApplication(executablePath, true)
+	if err != nil {
+		return "", fmt.Errorf("failed to check usability of %q: %w", executablePath, err)
+	}
+	if usable {
+		return RDAppParentPath, nil
+	}
+
+	// This fallback is mostly for running `npm run dev` and using the installed app because there is no app
+	// that rdctl would launch directly in dev mode.
+	candidatePath := filepath.Join("/Applications", "Rancher Desktop.app")
+	usable, err = checkUsableApplication(candidatePath, false)
+	if err != nil {
+		return "", fmt.Errorf("failed to check usability of %q: %w", candidatePath, err)
+	}
+	if usable {
+		return RDAppParentPath, nil
+	}
+
+	return "", errors.New("search locations exhausted")
+}

src/go/rdctl/pkg/utils/utils_linux.go

@@ -0,0 +1,38 @@
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// Returns the absolute path to the Rancher Desktop executable,
+// or an error if it was unable to find Rancher Desktop.
+func GetRDPath() (string, error) {
+	rdctlSymlinkPath, err := os.Executable()
+	if err != nil {
+		return "", fmt.Errorf("failed to get path to rdctl: %w", err)
+	}
+	rdctlPath, err := filepath.EvalSymlinks(rdctlSymlinkPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve %q: %w", rdctlSymlinkPath, err)
+	}
+	// rdctl should be at <installDir>/resources/resources/linux/bin/rdctl.
+	// rancher-desktop should be 5 directories up from that, at <installDir>/rancher-desktop.
+	normalParentPath := getParentDir(rdctlPath, 5)
+	candidatePaths := []string{
+		filepath.Join(normalParentPath, "rancher-desktop"),
+		"/opt/rancher-desktop/rancher-desktop",
+	}
+	for _, candidatePath := range candidatePaths {
+		usable, err := checkUsableApplication(candidatePath, true)
+		if err != nil {
+			return "", fmt.Errorf("failed to check usability of %q: %w", candidatePath, err)
+		}
+		if usable {
+			return candidatePath, nil
+		}
+	}
+	return "", errors.New("search locations exhausted")
+}

src/go/rdctl/pkg/utils/utils_unix.go

@@ -0,0 +1,39 @@
+//go:build linux || darwin
+
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"golang.org/x/sys/unix"
+	"io/fs"
+	"os"
+)
+
+// Verify that the candidatePath is usable as a Rancher Desktop "executable". This means:
+//   - check that candidatePath exists
+//   - if checkExecutability is true, check that candidatePath is a regular file,
+//     and that it is executable
+//
+// Note that candidatePath may not always be a file; in macOS, it may be a
+// .app directory.
+func checkUsableApplication(candidatePath string, checkExecutability bool) (bool, error) {
+	statResult, err := os.Stat(candidatePath)
+	if errors.Is(err, fs.ErrNotExist) {
+		return false, nil
+	}
+	if err != nil {
+		return false, fmt.Errorf("failed to get info on %q: %w", candidatePath, err)
+	}
+
+	if !checkExecutability {
+		return true, nil
+	}
+
+	if !statResult.Mode().IsRegular() {
+		return false, nil
+	}
+
+	err = unix.Access(candidatePath, unix.X_OK)
+	return err == nil, nil
+}

src/go/rdctl/pkg/utils/utils_windows.go

@@ -0,0 +1,68 @@
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+
+	"github.com/rancher-sandbox/rancher-desktop/src/go/rdctl/pkg/directories"
+)
+
+// Returns the absolute path to the Rancher Desktop executable.
+// Returns an empty string if the executable was not found.
+func GetRDPath() (string, error) {
+	rdctlSymlinkPath, err := os.Executable()
+	if err != nil {
+		return "", fmt.Errorf("failed to get path to rdctl: %w", err)
+	}
+	rdctlPath, err := filepath.EvalSymlinks(rdctlSymlinkPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve %q: %w", rdctlSymlinkPath, err)
+	}
+	// rdctl should be at <installDir>/resources/resources/win32/bin/rdctl.exe.
+	// rancher-desktop should be 5 directories up from that, at <installDir>/Rancher Desktop.exe.
+	normalParentPath := getParentDir(rdctlPath, 5)
+	candidatePath := filepath.Join(normalParentPath, "Rancher Desktop.exe")
+	_, err = os.Stat(candidatePath)
+	if err != nil && !errors.Is(err, fs.ErrNotExist) {
+		return "", fmt.Errorf("failed to check existence of %q: %w", candidatePath, err)
+	}
+	if err == nil {
+		return candidatePath, nil
+	}
+
+	homedir, err := os.UserHomeDir()
+	if err != nil {
+		homedir = ""
+	}
+	dataPaths := []string{}
+	// %LOCALAPPDATA%
+	dir, err := directories.GetLocalAppDataDirectory()
+	if err == nil {
+		dataPaths = append(dataPaths, dir)
+	}
+	// %APPDATA%
+	dir, err = directories.GetRoamingAppDataDirectory()
+	if err == nil {
+		dataPaths = append(dataPaths, dir)
+	}
+	dataPaths = append(
+		dataPaths,
+		filepath.Join(homedir, "AppData", "Local"),
+		filepath.Join(homedir, "AppData", "Roaming"),
+	)
+	for _, dataDir := range dataPaths {
+		candidatePath := filepath.Join(dataDir, "Programs", "Rancher Desktop", "Rancher Desktop.exe")
+		_, err := os.Stat(candidatePath)
+		if err != nil && !errors.Is(err, fs.ErrNotExist) {
+			return "", fmt.Errorf("failed to check existence of %q: %w", candidatePath, err)
+		}
+		if err == nil {
+			return candidatePath, nil
+		}
+	}
+
+	return "", errors.New("search locations exhausted")
+}