Support CNI DNS capabilities.

Signed-off-by: Lantao Liu <lantaol@google.com>

vendor/github.com/containerd/go-cni/namespace_opts.go

@@ -42,6 +42,14 @@ func WithCapabilityBandWidth(bandWidth BandWidth) NamespaceOpts {
 	}
 }
 
+// WithCapabilityDNS adds support for dns
+func WithCapabilityDNS(dns DNS) NamespaceOpts {
+	return func(c *Namespace) error {
+		c.capabilityArgs["dns"] = dns
+		return nil
+	}
+}
+
 func WithCapability(name string, capability interface{}) NamespaceOpts {
 	return func(c *Namespace) error {
 		c.capabilityArgs[name] = capability

vendor/github.com/containerd/go-cni/types.go

@@ -53,3 +53,13 @@ type BandWidth struct {
 	EgressRate   uint64
 	EgressBurst  uint64
 }
+
+// DNS defines the dns config
+type DNS struct {
+	// List of DNS servers of the cluster.
+	Servers []string
+	// List of DNS search domains of the cluster.
+	Searches []string
+	// List of DNS options.
+	Options []string
+}