fix: improve timezone detection to work on macOS Sequoia, for ddev#6468…

… (ddev#6603)

pkg/ddevapp/ddevapp.go

@@ -1187,28 +1187,13 @@ func (app *DdevApp) GetLocalTimezone() (string, error) {
 		timezone = os.Getenv("TZ")
 	} else {
 		localtimeFile := filepath.Join("/etc", "localtime")
-		timezoneFile, err := filepath.EvalSymlinks(localtimeFile)
+		var err error
+		timezone, err = filepath.EvalSymlinks(localtimeFile)
 		if err != nil {
 			return "", fmt.Errorf("unable to read timezone from %s file: %v", localtimeFile, err)
 		}
-		// /etc/localtime is a symlink to a file, for example:
-		// /usr/share/zoneinfo/Europe/London on Linux and WSL2
-		// /var/db/timezone/zoneinfo/Europe/London on macOS (the exact path to /zoneinfo/ may differ)
-		// We can search for anything after /zoneinfo/ in the file path
-		parts := strings.Split(strings.TrimSpace(timezoneFile), "/zoneinfo/")
-		if len(parts) != 2 {
-			return "", fmt.Errorf("unable to read timezone from %s file", timezoneFile)
-		}
-		timezone = parts[1]
-		if timezone == "" {
-			return "", fmt.Errorf("unable to read timezone from %s file", timezoneFile)
-		}
-	}
-	_, err := time.LoadLocation(timezone)
-	if err != nil {
-		return "", fmt.Errorf("failed to load timezone '%s': %v", timezone, err)
 	}
-	return timezone, nil
+	return util.GetTimezone(timezone)
 }
 
 // Start initiates docker-compose up

pkg/util/utils.go

@@ -9,6 +9,7 @@ import (
 	osexec "os/exec"
 	"os/user"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"strings"
 	"time"
@@ -388,3 +389,33 @@ func Chmod(path string, mode os.FileMode) error {
 	}
 	return os.Chmod(path, mode)
 }
+
+// GetTimezone tries to find local timezone from the path, that can be
+// either $TZ environment variable or /etc/localtime symlink
+func GetTimezone(path string) (string, error) {
+	// Use case-insensitive search for /zoneinfo/ in the file path.
+	regex := regexp.MustCompile(`(?i)/.*?zoneinfo.*?/`)
+	parts := regex.Split(strings.TrimSpace(path), 2)
+	if len(parts) != 2 {
+		// If this is not a path, but timezone, return it.
+		_, err := time.LoadLocation(path)
+		if err == nil {
+			return path, nil
+		}
+		return "", fmt.Errorf("unable to read timezone from %s", path)
+	}
+	timezone := parts[1]
+	// Remove leading prefixes if they exist.
+	// https://stackoverflow.com/a/67888343/8097891
+	for _, prefix := range []string{"posix/", "right/"} {
+		timezone = strings.TrimPrefix(timezone, prefix)
+	}
+	if timezone == "" {
+		return "", fmt.Errorf("unable to read timezone from %s", path)
+	}
+	_, err := time.LoadLocation(timezone)
+	if err != nil {
+		return "", fmt.Errorf("failed to load timezone '%s': %v", timezone, err)
+	}
+	return timezone, nil
+}

pkg/util/utils_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/ddev/ddev/pkg/output"
 	"github.com/ddev/ddev/pkg/util"
 	asrt "github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 // TestRandString ensures that RandString only generates string of the correct value and characters.
@@ -194,3 +195,38 @@ func TestArrayToReadableOutput(t *testing.T) {
 	_, err := util.ArrayToReadableOutput([]string{})
 	assert.EqualErrorf(err, "empty slice", "Expected error when passing an empty slice")
 }
+
+// TestGetTimezone tests GetTimezone
+func TestGetTimezone(t *testing.T) {
+	testCases := []struct {
+		description string
+		input       string
+		result      string
+		error       string
+	}{
+		{"$TZ env var", "Europe/London", "Europe/London", ""},
+		{"Linux /etc/localtime symlink", "/usr/share/zoneinfo/Europe/London", "Europe/London", ""},
+		{"Linux /etc/localtime posix symlink", "/usr/share/zoneinfo/posix/Europe/London", "Europe/London", ""},
+		{"Linux /etc/localtime right symlink", "/usr/share/zoneinfo/right/Europe/London", "Europe/London", ""},
+		{"/etc/localtime is not a symlink", "/etc/localtime", "", "unable to read timezone from /etc/localtime"},
+		{"macOS /etc/localtime symlink", "/var/db/timezone/zoneinfo/Europe/London", "Europe/London", ""},
+		{"macOS Sonoma /etc/localtime symlink", "/private/var/db/timezone/tz/2024a.1.0/zoneinfo/Europe/London", "Europe/London", ""},
+		{"macOS Sequoia /etc/localtime symlink", "/usr/share/zoneinfo.default/Europe/London", "Europe/London", ""},
+		{"Case-insensitive search for /zoneinfo/ in the path", "/path/to/TestZoneInfoTest/Europe/London", "Europe/London", ""},
+		{"Timezone has wrong format", "/Europe/London", "", "unable to read timezone from /Europe/London"},
+		{"Not real timezone", "Europe/Test", "", "unable to read timezone from Europe/Test"},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			timezone, err := util.GetTimezone(tc.input)
+			require.Equal(t, tc.result, timezone)
+			if tc.error == "" {
+				require.NoError(t, err)
+			} else {
+				require.Error(t, err)
+				require.Contains(t, err.Error(), tc.error)
+			}
+		})
+	}
+}