fix/timesync: Ensure that auto-update waits for time sync

- Added check to not attempt auto update if time sync is needed and not yet successful (delays 30 second to recheck).
- Added resync of time when DHCP or link state changes if online
- Added conditional* fallback from configured* NTP servers to the IP-named NTP servers, and then to the DNS named ones if that fails
- Added conditional* fallback from the configured* HTTP servers to the default DNS named ones.
- Uses the configuration* option for how many queries to run in parallel
- Added known static IPs for time servers (in case DNS resolution isn't up yet)
- Added time.cloudflare.com to fall-back NTP servers

* Note: The UI for configuring many of these things doesn't exist yet, but the defaults are reasonable

Fix lint issue

Delete trailing tabs

Added fallback to NTP via hostnames

Fixes lint issue and logs the resultant time (and mode)

Author: IDisposable

internal/network/netif.go

@@ -48,7 +48,7 @@ type NetworkInterfaceOptions struct {
 	DefaultHostname   string
 	OnStateChange     func(state *NetworkInterfaceState)
 	OnInitialCheck    func(state *NetworkInterfaceState)
-	OnDhcpLeaseChange func(lease *udhcpc.Lease)
+	OnDhcpLeaseChange func(lease *udhcpc.Lease, state *NetworkInterfaceState)
 	OnConfigChange    func(config *NetworkConfig)
 	NetworkConfig     *NetworkConfig
 }
@@ -94,7 +94,7 @@ func NewNetworkInterfaceState(opts *NetworkInterfaceOptions) (*NetworkInterfaceS
 			_ = s.updateNtpServersFromLease(lease)
 			_ = s.setHostnameIfNotSame()
 
-			opts.OnDhcpLeaseChange(lease)
+			opts.OnDhcpLeaseChange(lease, s)
 		},
 	})
 

internal/timesync/ntp.go

@@ -9,17 +9,32 @@ import (
 	"github.com/beevik/ntp"
 )
 
-var defaultNTPServers = []string{
+var defaultNTPServerIPs = []string{
+	// These servers are known by static IP and as such don't need DNS lookups
+	// These are from Google and Cloudflare since if they're down, the internet
+	// is broken anyway
+	"162.159.200.1",      // time.cloudflare.com IPv4
+	"162.159.200.123",    // time.cloudflare.com IPv4
+	"2606:4700:f1::1",    // time.cloudflare.com IPv6
+	"2606:4700:f1::123",  // time.cloudflare.com IPv6
+	"216.239.35.0",       // time.google.com IPv4
+	"216.239.35.4",       // time.google.com IPv4
+	"216.239.35.8",       // time.google.com IPv4
+	"216.239.35.12",      // time.google.com IPv4
+	"2001:4860:4806::",   // time.google.com IPv6
+	"2001:4860:4806:4::", // time.google.com IPv6
+	"2001:4860:4806:8::", // time.google.com IPv6
+	"2001:4860:4806:c::", // time.google.com IPv6
+}
+
+var defaultNTPServerHostnames = []string{
+	// should use something from https://github.com/jauderho/public-ntp-servers
 	"time.apple.com",
 	"time.aws.com",
 	"time.windows.com",
 	"time.google.com",
-	"162.159.200.123",   // time.cloudflare.com IPv4
-	"2606:4700:f1::123", // time.cloudflare.com IPv6
-	"0.pool.ntp.org",
-	"1.pool.ntp.org",
-	"2.pool.ntp.org",
-	"3.pool.ntp.org",
+	"time.cloudflare.com",
+	"pool.ntp.org",
 }
 
 func (t *TimeSync) queryNetworkTime(ntpServers []string) (now *time.Time, offset *time.Duration) {

internal/timesync/timesync.go

@@ -158,6 +158,7 @@ func (t *TimeSync) Sync() error {
 	var (
 		now    *time.Time
 		offset *time.Duration
+		log    zerolog.Logger
 	)
 
 	metricTimeSyncCount.Inc()
@@ -166,54 +167,54 @@ func (t *TimeSync) Sync() error {
 
 Orders:
 	for _, mode := range syncMode.Ordering {
+		log = t.l.With().Str("mode", mode).Logger()
 		switch mode {
 		case "ntp_user_provided":
 			if syncMode.Ntp {
-				t.l.Info().Msg("using NTP custom servers")
+				log.Info().Msg("using NTP custom servers")
 				now, offset = t.queryNetworkTime(t.networkConfig.TimeSyncNTPServers)
 				if now != nil {
-					t.l.Info().Str("source", "NTP").Time("now", *now).Msg("time obtained")
 					break Orders
 				}
 			}
 		case "ntp_dhcp":
 			if syncMode.Ntp {
-				t.l.Info().Msg("using NTP servers from DHCP")
+				log.Info().Msg("using NTP servers from DHCP")
 				now, offset = t.queryNetworkTime(t.dhcpNtpAddresses)
 				if now != nil {
-					t.l.Info().Str("source", "NTP DHCP").Time("now", *now).Msg("time obtained")
 					break Orders
 				}
 			}
 		case "ntp":
 			if syncMode.Ntp && syncMode.NtpUseFallback {
-				t.l.Info().Msg("using NTP fallback")
-				now, offset = t.queryNetworkTime(defaultNTPServers)
+				log.Info().Msg("using NTP fallback IPs")
+				now, offset = t.queryNetworkTime(defaultNTPServerIPs)
+				if now == nil {
+					log.Info().Msg("using NTP fallback hostnames")
+					now, offset = t.queryNetworkTime(defaultNTPServerHostnames)
+				}
 				if now != nil {
-					t.l.Info().Str("source", "NTP fallback").Time("now", *now).Msg("time obtained")
 					break Orders
 				}
 			}
 		case "http_user_provided":
 			if syncMode.Http {
-				t.l.Info().Msg("using HTTP custom URLs")
+				log.Info().Msg("using HTTP custom URLs")
 				now = t.queryAllHttpTime(t.networkConfig.TimeSyncHTTPUrls)
 				if now != nil {
-					t.l.Info().Str("source", "HTTP").Time("now", *now).Msg("time obtained")
 					break Orders
 				}
 			}
 		case "http":
 			if syncMode.Http && syncMode.HttpUseFallback {
-				t.l.Info().Msg("using HTTP fallback")
+				log.Info().Msg("using HTTP fallback")
 				now = t.queryAllHttpTime(defaultHTTPUrls)
 				if now != nil {
-					t.l.Info().Str("source", "HTTP fallback").Time("now", *now).Msg("time obtained")
 					break Orders
 				}
 			}
 		default:
-			t.l.Warn().Str("mode", mode).Msg("unknown time sync mode, skipping")
+			log.Warn().Msg("unknown time sync mode, skipping")
 		}
 	}
 
@@ -226,6 +227,8 @@ Orders:
 		now = &newNow
 	}
 
+	log.Info().Time("now", *now).Msg("time obtained")
+
 	err := t.setSystemTime(*now)
 	if err != nil {
 		return fmt.Errorf("failed to set system time: %w", err)

main.go

@@ -96,16 +96,25 @@ func Main() {
 			if !config.AutoUpdateEnabled {
 				return
 			}
+
+			if isTimeSyncNeeded() || !timeSync.IsSyncSuccess() {
+				logger.Debug().Msg("system time is not synced, will retry in 30 seconds")
+				time.Sleep(30 * time.Second)
+				continue
+			}
+
 			if currentSession != nil {
 				logger.Debug().Msg("skipping update since a session is active")
 				time.Sleep(1 * time.Minute)
 				continue
 			}
+
 			includePreRelease := config.IncludePreRelease
 			err = TryUpdate(context.Background(), GetDeviceID(), includePreRelease)
 			if err != nil {
 				logger.Warn().Err(err).Msg("failed to auto update")
 			}
+
 			time.Sleep(1 * time.Hour)
 		}
 	}()

network.go

@@ -15,7 +15,7 @@ var (
 	networkState *network.NetworkInterfaceState
 )
 
-func networkStateChanged() {
+func networkStateChanged(isOnline bool) {
 	// do not block the main thread
 	go waitCtrlAndRequestDisplayUpdate(true)
 
@@ -37,6 +37,13 @@ func networkStateChanged() {
 			networkState.GetFQDN(),
 		}, true)
 	}
+
+	// if the network is now online, trigger an NTP sync if still needed
+	if isOnline && timeSync != nil && (isTimeSyncNeeded() || !timeSync.IsSyncSuccess()) {
+		if err := timeSync.Sync(); err != nil {
+			logger.Warn().Str("error", err.Error()).Msg("unable to sync time on network state change")
+		}
+	}
 }
 
 func initNetwork() error {
@@ -48,13 +55,13 @@ func initNetwork() error {
 		NetworkConfig:   config.NetworkConfig,
 		Logger:          networkLogger,
 		OnStateChange: func(state *network.NetworkInterfaceState) {
-			networkStateChanged()
+			networkStateChanged(state.IsOnline())
 		},
 		OnInitialCheck: func(state *network.NetworkInterfaceState) {
-			networkStateChanged()
+			networkStateChanged(state.IsOnline())
 		},
-		OnDhcpLeaseChange: func(lease *udhcpc.Lease) {
-			networkStateChanged()
+		OnDhcpLeaseChange: func(lease *udhcpc.Lease, state *network.NetworkInterfaceState) {
+			networkStateChanged(state.IsOnline())
 
 			if currentSession == nil {
 				return
@@ -64,7 +71,15 @@ func initNetwork() error {
 		},
 		OnConfigChange: func(networkConfig *network.NetworkConfig) {
 			config.NetworkConfig = networkConfig
-			networkStateChanged()
+			networkStateChanged(false)
+
+			if mDNS != nil {
+				_ = mDNS.SetListenOptions(networkConfig.GetMDNSMode())
+				_ = mDNS.SetLocalNames([]string{
+					networkState.GetHostname(),
+					networkState.GetFQDN(),
+				}, true)
+			}
 		},
 	})