cmd/k8s-operator: ensure that operator can write to config dir

Updates tailscale/tailscale#10638

Signed-off-by: Irbe Krumina <irbe@tailscale.com>

cmd/k8s-operator/operator.go

@@ -127,9 +127,14 @@ func initTSNet(zlog *zap.SugaredLogger) (*tsnet.Server, *tailscale.Client) {
 	tsClient := tailscale.NewClient("-", nil)
 	tsClient.HTTPClient = credentials.Client(context.Background())
 
+	configDir, err := os.MkdirTemp(os.TempDir(), "tsnet-config")
+	if err != nil {
+		startlog.Fatalf("error creating config directory for tsnet: %v", err)
+	}
 	s := &tsnet.Server{
 		Hostname: hostname,
 		Logf:     zlog.Named("tailscaled").Debugf,
+		Dir:      configDir,
 	}
 	if kubeSecret != "" {
 		st, err := kubestore.New(logger.Discard, kubeSecret)