Set guest timezone from host setting

Allow explicit override via lima.yaml. Signed-off-by: Jan Dubois <jan.dubois@suse.com>

Author: jandubois

examples/default.yaml

@@ -259,6 +259,11 @@ rosetta:
  # 🟢 Builtin default: false
  binfmt: null
 
+# Specify the timezone name (as used by the zoneinfo database). Specify the empty string
+# to not set a timezone in the instance.
+# 🟢 Builtin default: use name from /etc/timezone or deduce from symlink target of /etc/localtime
+timezone: null
+
 firmware:
  # Use legacy BIOS instead of UEFI. Ignored for aarch64.
  # 🟢 Builtin default: false

pkg/cidata/cidata.TEMPLATE.d/boot/04-persistent-data-volume.sh

@@ -30,6 +30,18 @@ if [ "$(awk '$2 == "/" {print $3}' /proc/mounts)" == "tmpfs" ]; then
 # Update /etc files that might have changed during this boot
 cp /etc/network/interfaces /mnt/data/etc/network/
 cp /etc/resolv.conf /mnt/data/etc/
+if [ -f /etc/localtime ]; then
+# Preserve symlink
+cp -d /etc/localtime /mnt/data/etc/
+# setup-timezone copies the single zoneinfo file into /etc/zoneinfo and targets the symlink there
+if [ -d /etc/zoneinfo ]; then
+rm -rf /mnt/data/etc/zoneinfo
+cp -r /etc/zoneinfo /mnt/data/etc
+fi
+fi
+if [ -f /etc/timezone ]; then
+cp /etc/timezone /mnt/data/etc/
+fi
 # TODO there are probably others that should be updated as well
 else
 # Find an unpartitioned disk and create data-volume

pkg/cidata/cidata.TEMPLATE.d/user-data

@@ -14,6 +14,10 @@ mounts:
 {{- end }}
 {{- end }}
 
+{{- if .TimeZone }}
+timezone: {{.TimeZone}}
+{{- end }}
+
 users:
  - name: "{{.User}}"
  uid: "{{.UID}}"

pkg/cidata/cidata.go

@@ -136,6 +136,7 @@ func GenerateISO9660(instDir, name string, y *limayaml.LimaYAML, udpDNSLocalPort
 VMType: *y.VMType,
 VSockPort: vsockPort,
 Plain: *y.Plain,
+TimeZone: *y.TimeZone,
 }
 
 firstUsernetIndex := limayaml.FirstUsernetIndex(y)

pkg/cidata/template.go

@@ -82,6 +82,7 @@ type TemplateArgs struct {
 VMType string
 VSockPort int
 Plain bool
+TimeZone string
 }
 
 func ValidateTemplateArgs(args TemplateArgs) error {

pkg/limayaml/defaults.go

@@ -9,20 +9,20 @@ import (
 "path/filepath"
 "runtime"
 "strconv"
+"strings"
 "text/template"
 
 "github.com/docker/go-units"
-"github.com/lima-vm/lima/pkg/networks"
-"github.com/lima-vm/lima/pkg/ptr"
 "github.com/pbnjay/memory"
+"github.com/sirupsen/logrus"
+"golang.org/x/sys/cpu"
 
 "github.com/lima-vm/lima/pkg/guestagent/api"
+"github.com/lima-vm/lima/pkg/networks"
 "github.com/lima-vm/lima/pkg/osutil"
+"github.com/lima-vm/lima/pkg/ptr"
 "github.com/lima-vm/lima/pkg/store/dirnames"
 "github.com/lima-vm/lima/pkg/store/filenames"
-"github.com/sirupsen/logrus"
-
-"golang.org/x/sys/cpu"
 )
 
 const (
@@ -83,6 +83,26 @@ func MACAddress(uniqueID string) string {
 return hw.String()
 }
 
+func hostTimeZone() string {
+// WSL2 will automatically set the timezone
+if runtime.GOOS != "windows" {
+tz, err := os.ReadFile("/etc/timezone")
+if err == nil {
+return strings.TrimSpace(string(tz))
+}
+zoneinfoFile, err := filepath.EvalSymlinks("/etc/localtime")
+if err == nil {
+for baseDir := filepath.Dir(zoneinfoFile); baseDir != "/"; baseDir = filepath.Dir(baseDir) {
+if _, err = os.Stat(filepath.Join(baseDir, "Etc/UTC")); err == nil {
+return strings.TrimPrefix(zoneinfoFile, baseDir+"/")
+}
+}
+logrus.Warnf("could not locate zoneinfo directory from %q", zoneinfoFile)
+}
+}
+return ""
+}
+
 func defaultCPUs() int {
 const x = 4
 if hostCPUs := runtime.NumCPU(); hostCPUs < x {
@@ -325,6 +345,16 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 }
 }
 
+if y.TimeZone == nil {
+y.TimeZone = d.TimeZone
+}
+if o.TimeZone != nil {
+y.TimeZone = o.TimeZone
+}
+if y.TimeZone == nil {
+y.TimeZone = ptr.Of(hostTimeZone())
+}
+
 if y.SSH.LocalPort == nil {
 y.SSH.LocalPort = d.SSH.LocalPort
 }
@@ -731,6 +761,7 @@ func fixUpForPlainMode(y *LimaYAML) {
 y.Containerd.User = ptr.Of(false)
 y.Rosetta.BinFmt = ptr.Of(false)
 y.Rosetta.Enabled = ptr.Of(false)
+y.TimeZone = ptr.Of("")
 }
 
 func executeGuestTemplate(format string) (bytes.Buffer, error) {

pkg/limayaml/defaults_test.go

@@ -85,6 +85,7 @@ func TestFillDefault(t *testing.T) {
 ForwardX11: ptr.Of(false),
 ForwardX11Trusted: ptr.Of(false),
 },
+TimeZone: ptr.Of(hostTimeZone()),
 Firmware: Firmware{
 LegacyBIOS: ptr.Of(false),
 },
@@ -181,6 +182,7 @@ func TestFillDefault(t *testing.T) {
 "-----BEGIN CERTIFICATE-----\nYOUR-ORGS-TRUSTED-CA-CERT\n-----END CERTIFICATE-----\n",
 },
 },
+TimeZone: ptr.Of("Antarctica"),
 Firmware: Firmware{
 LegacyBIOS: ptr.Of(false),
 Images: []FileWithVMType{
@@ -273,6 +275,7 @@ func TestFillDefault(t *testing.T) {
 },
 }
 
+expect.TimeZone = y.TimeZone
 expect.Firmware = y.Firmware
 
 expect.Rosetta = Rosetta{
@@ -320,6 +323,7 @@ func TestFillDefault(t *testing.T) {
 ForwardX11: ptr.Of(false),
 ForwardX11Trusted: ptr.Of(false),
 },
+TimeZone: ptr.Of("Zulu"),
 Firmware: Firmware{
 LegacyBIOS: ptr.Of(true),
 Images: []FileWithVMType{
@@ -512,6 +516,7 @@ func TestFillDefault(t *testing.T) {
 ForwardX11: ptr.Of(false),
 ForwardX11Trusted: ptr.Of(false),
 },
+TimeZone: ptr.Of("Universal"),
 Firmware: Firmware{
 LegacyBIOS: ptr.Of(true),
 },

pkg/limayaml/limayaml.go

@@ -39,6 +39,7 @@ type LimaYAML struct {
 CACertificates CACertificates `yaml:"caCerts,omitempty" json:"caCerts,omitempty"`
 Rosetta Rosetta `yaml:"rosetta,omitempty" json:"rosetta,omitempty"`
 Plain *bool `yaml:"plain,omitempty" json:"plain,omitempty"`
+TimeZone *string `yaml:"timezone,omitempty" json:"timezone,omitempty"`
 }
 
 type (