CRI: Add dns option, rename DNSOption to DNSConfig.

pkg/kubelet/kuberuntime/helpers.go

@@ -37,6 +37,11 @@ const (
 	minQuotaPeriod = 1000
 )
 
+var (
+	// The default dns opt strings
+	defaultDNSOptions = []string{"ndots:5"}
+)
+
 type podsByID []*kubecontainer.Pod
 
 func (b podsByID) Len() int           { return len(b) }