fix: wait for udevd before starting sync

Fixes #8074

One part of the fix is to wait for udevd to be ready, as anyways before
udevd is ready network interfaces are not ready, so sync is not
possible.

Second part is that now u-root's rtc package supports closing rtc
devices, so we can properly open/close it as part of the sync loop (vs.
previous workaround with sync.Once).

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>

internal/app/machined/pkg/controllers/time/sync.go

@@ -17,6 +17,7 @@ import (
 	"github.com/siderolabs/gen/optional"
 	"go.uber.org/zap"
 
+	"github.com/siderolabs/talos/internal/app/machined/pkg/controllers/runtime"
 	v1alpha1runtime "github.com/siderolabs/talos/internal/app/machined/pkg/runtime"
 	"github.com/siderolabs/talos/internal/pkg/ntp"
 	"github.com/siderolabs/talos/pkg/machinery/resources/config"
@@ -39,19 +40,7 @@ func (ctrl *SyncController) Name() string {
 
 // Inputs implements controller.Controller interface.
 func (ctrl *SyncController) Inputs() []controller.Input {
-	return []controller.Input{
-		{
-			Namespace: network.NamespaceName,
-			Type:      network.TimeServerStatusType,
-			ID:        optional.Some(network.TimeServerID),
-			Kind:      controller.InputWeak,
-		},
-		{
-			Namespace: config.NamespaceName,
-			Type:      config.MachineConfigType,
-			ID:        optional.Some(config.V1Alpha1ID),
-		},
-	}
+	return nil
 }
 
 // Outputs implements controller.Controller interface.
@@ -89,6 +78,25 @@ func (ctrl *SyncController) Run(ctx context.Context, r controller.Runtime, logge
 		}
 	}
 
+	// wait for udevd to be healthy, which implies that all RTC devices
+	if err := runtime.WaitForDevicesReady(ctx, r,
+		[]controller.Input{
+			{
+				Namespace: network.NamespaceName,
+				Type:      network.TimeServerStatusType,
+				ID:        optional.Some(network.TimeServerID),
+				Kind:      controller.InputWeak,
+			},
+			{
+				Namespace: config.NamespaceName,
+				Type:      config.MachineConfigType,
+				ID:        optional.Some(config.V1Alpha1ID),
+			},
+		},
+	); err != nil {
+		return err
+	}
+
 	var (
 		syncCtx       context.Context
 		syncCtxCancel context.CancelFunc

internal/app/machined/pkg/controllers/time/sync_test.go

@@ -30,6 +30,7 @@ import (
 	"github.com/siderolabs/talos/pkg/machinery/constants"
 	"github.com/siderolabs/talos/pkg/machinery/resources/config"
 	"github.com/siderolabs/talos/pkg/machinery/resources/network"
+	runtimeres "github.com/siderolabs/talos/pkg/machinery/resources/runtime"
 	timeresource "github.com/siderolabs/talos/pkg/machinery/resources/time"
 	v1alpha1resource "github.com/siderolabs/talos/pkg/machinery/resources/v1alpha1"
 )
@@ -62,6 +63,11 @@ func (suite *SyncSuite) SetupTest() {
 
 	suite.runtime, err = runtime.NewRuntime(suite.state, zaptest.NewLogger(suite.T()))
 	suite.Require().NoError(err)
+
+	// create fake device ready status
+	deviceStatus := runtimeres.NewDevicesStatus(runtimeres.NamespaceName, runtimeres.DevicesID)
+	deviceStatus.TypedSpec().Ready = true
+	suite.Require().NoError(suite.state.Create(suite.ctx, deviceStatus))
 }
 
 func (suite *SyncSuite) startRuntime() {

internal/pkg/ntp/ntp.go

@@ -51,6 +51,7 @@ type Syncer struct {
 	CurrentTime CurrentTimeFunc
 	NTPQuery    QueryFunc
 	AdjustTime  AdjustTimeFunc
+	DisableRTC  bool
 }
 
 // Measurement is a struct containing correction data based on a time request.
@@ -159,14 +160,19 @@ func (syncer *Syncer) isSpike(resp *ntp.Response) bool {
 //
 //nolint:gocyclo,cyclop
 func (syncer *Syncer) Run(ctx context.Context) {
-	RTCClockInitialize.Do(func() {
-		var err error
+	var (
+		rtcClock *rtc.RTC
+		err      error
+	)
 
-		RTCClock, err = rtc.OpenRTC()
+	if !syncer.DisableRTC {
+		rtcClock, err = rtc.OpenRTC()
 		if err != nil {
 			syncer.logger.Error("failure opening RTC, ignored", zap.Error(err))
+		} else {
+			defer rtcClock.Close() //nolint:errcheck
 		}
-	})
+	}
 
 	pollInterval := time.Duration(0)
 
@@ -216,7 +222,7 @@ func (syncer *Syncer) Run(ctx context.Context) {
 		)
 
 		if resp != nil && !spike {
-			err = syncer.adjustTime(resp.ClockOffset, resp.Leap, lastSyncServer, pollInterval)
+			err = syncer.adjustTime(resp.ClockOffset, resp.Leap, lastSyncServer, pollInterval, rtcClock)
 
 			if err == nil {
 				if !syncer.timeSyncNotified {
@@ -415,7 +421,7 @@ func log2i(v uint64) int {
 // adjustTime adds an offset to the current time.
 //
 //nolint:gocyclo
-func (syncer *Syncer) adjustTime(offset time.Duration, leapSecond ntp.LeapIndicator, server string, nextPollInterval time.Duration) error {
+func (syncer *Syncer) adjustTime(offset time.Duration, leapSecond ntp.LeapIndicator, server string, nextPollInterval time.Duration, rtcClock *rtc.RTC) error {
 	var (
 		buf  bytes.Buffer
 		req  unix.Timex
@@ -509,8 +515,8 @@ func (syncer *Syncer) adjustTime(offset time.Duration, leapSecond ntp.LeapIndica
 		}
 
 		if jump {
-			if RTCClock != nil {
-				if rtcErr := RTCClock.Set(time.Now().Add(offset)); rtcErr != nil {
+			if rtcClock != nil {
+				if rtcErr := rtcClock.Set(time.Now().Add(offset)); rtcErr != nil {
 					syncer.logger.Error("error syncing RTC", zap.Error(rtcErr))
 				} else {
 					syncer.logger.Info("synchronized RTC with system clock")

internal/pkg/ntp/ntp_test.go

@@ -40,11 +40,6 @@ func TestNTPSuite(t *testing.T) {
 	suite.Run(t, new(NTPSuite))
 }
 
-func (suite *NTPSuite) SetupSuite() {
-	// disable RTC clock
-	ntp.RTCClockInitialize.Do(func() {})
-}
-
 func (suite *NTPSuite) SetupTest() {
 	suite.systemClock = time.Now().UTC()
 	suite.clockAdjustments = nil
@@ -194,6 +189,7 @@ func (suite *NTPSuite) TestSync() {
 
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
+	syncer.DisableRTC = true
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
@@ -225,6 +221,7 @@ func (suite *NTPSuite) TestSyncContinuous() {
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
 	syncer.NTPQuery = suite.fakeQuery
+	syncer.DisableRTC = true
 
 	syncer.MinPoll = time.Second
 	syncer.MaxPoll = time.Second
@@ -273,6 +270,7 @@ func (suite *NTPSuite) TestSyncKissOfDeath() {
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
 	syncer.NTPQuery = suite.fakeQuery
+	syncer.DisableRTC = true
 
 	syncer.MinPoll = time.Second
 	syncer.MaxPoll = time.Second
@@ -326,6 +324,7 @@ func (suite *NTPSuite) TestSyncWithSpikes() {
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
 	syncer.NTPQuery = suite.fakeQuery
+	syncer.DisableRTC = true
 
 	syncer.MinPoll = time.Second
 	syncer.MaxPoll = time.Second
@@ -377,6 +376,7 @@ func (suite *NTPSuite) TestSyncChangeTimeservers() {
 
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
+	syncer.DisableRTC = true
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
@@ -416,6 +416,7 @@ func (suite *NTPSuite) TestSyncIterateTimeservers() {
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
 	syncer.NTPQuery = suite.fakeQuery
+	syncer.DisableRTC = true
 
 	syncer.MinPoll = time.Second
 	syncer.MaxPoll = time.Second
@@ -468,6 +469,7 @@ func (suite *NTPSuite) TestSyncEpochChange() {
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
 	syncer.NTPQuery = suite.fakeQuery
+	syncer.DisableRTC = true
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
@@ -507,6 +509,7 @@ func (suite *NTPSuite) TestSyncSwitchTimeservers() {
 	syncer.AdjustTime = suite.adjustSystemClock
 	syncer.CurrentTime = suite.getSystemClock
 	syncer.NTPQuery = suite.fakeQuery
+	syncer.DisableRTC = true
 
 	syncer.MinPoll = time.Second
 	syncer.MaxPoll = time.Second

internal/pkg/ntp/rtc.go

@@ -1,17 +0,0 @@
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this
-// file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-package ntp
-
-import (
-	"sync"
-
-	"github.com/u-root/u-root/pkg/rtc"
-)
-
-// Global instance of RTC clock because `rtc` doesn't support closing.
-var (
-	RTCClock           *rtc.RTC
-	RTCClockInitialize sync.Once
-)