chore(vpn): send info, debug logs over tunnel (#18240)

Closes https://github.com/coder/internal/issues/397

cli/vpndaemon_windows.go

@@ -65,7 +65,6 @@ func (r *RootCmd) vpnDaemonRun() *serpent.Command {
 			logger.Info(ctx, "starting tunnel")
 			tunnel, err := vpn.NewTunnel(ctx, logger, pipe, vpn.NewClient(),
 				vpn.UseOSNetworkingStack(),
-				vpn.UseAsLogger(),
 				vpn.UseCustomLogSinks(sinks...),
 			)
 			if err != nil {

vpn/dylib/lib.go

@@ -46,7 +46,10 @@ func OpenTunnel(cReadFD, cWriteFD int32) int32 {
 		return ErrOpenPipe
 	}
 
-	_, err = vpn.NewTunnel(ctx, slog.Make(), conn, vpn.NewClient(),
+	// We log everything, as filtering is done by whatever renders the OS
+	// logs.
+	_, err = vpn.NewTunnel(ctx, slog.Make().Leveled(slog.LevelDebug), conn,
+		vpn.NewClient(),
 		vpn.UseOSNetworkingStack(),
 		vpn.UseAsLogger(),
 	)

vpn/tunnel.go

@@ -46,9 +46,6 @@ type Tunnel struct {
 
 	logger slog.Logger
 
-	logMu sync.Mutex
-	logs  []*TunnelMessage
-
 	client Client
 
 	// clientLogger is a separate logger than `logger` when the `UseAsLogger`
@@ -300,29 +297,22 @@ func (t *Tunnel) stop(*StopRequest) error {
 var _ slog.Sink = &Tunnel{}
 
 func (t *Tunnel) LogEntry(_ context.Context, e slog.SinkEntry) {
-	t.logMu.Lock()
-	defer t.logMu.Unlock()
-	t.logs = append(t.logs, &TunnelMessage{
+	msg := &TunnelMessage{
 		Msg: &TunnelMessage_Log{
 			Log: sinkEntryToPb(e),
 		},
-	})
-}
-
-func (t *Tunnel) Sync() {
-	t.logMu.Lock()
-	logs := t.logs
-	t.logs = nil
-	t.logMu.Unlock()
-	for _, msg := range logs {
-		select {
-		case <-t.ctx.Done():
-			return
-		case t.sendCh <- msg:
-		}
+	}
+	select {
+	case <-t.updater.ctx.Done():
+		return
+	case <-t.ctx.Done():
+		return
+	case t.sendCh <- msg:
 	}
 }
 
+func (*Tunnel) Sync() {}
+
 func sinkEntryToPb(e slog.SinkEntry) *Log {
 	l := &Log{
 		// #nosec G115 - Safe conversion for log levels which are small positive integers
@@ -583,6 +573,8 @@ func (u *updater) sendAgentUpdate() {
 		return
 	}
 
+	u.logger.Debug(u.ctx, "sending agent update")
+
 	msg := &TunnelMessage{
 		Msg: &TunnelMessage_PeerUpdate{
 			PeerUpdate: &PeerUpdate{