[WIP]Fix CNI plugin to care DNS changes in latest CNI

plugins/ipam/host-local/main.go

@@ -67,7 +67,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		if err != nil {
 			return err
 		}
-		result.DNS = *dns
+		result.DNS = dns
 	}
 
 	store, err := disk.New(ipamConf.Name, ipamConf.DataDir)

plugins/ipam/static/main.go

@@ -263,7 +263,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 
 	result := &current.Result{
 		CNIVersion: current.ImplementedSpecVersion,
-		DNS:        ipamConf.DNS,
+		DNS:        &ipamConf.DNS,
 		Routes:     ipamConf.Routes,
 	}
 	for _, v := range ipamConf.Addresses {

plugins/main/bridge/bridge.go

@@ -734,7 +734,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 
 	// Use incoming DNS settings if provided, otherwise use the
 	// settings that were already configued by the IPAM plugin
-	if dnsConfSet(n.DNS) {
+	if n.DNS != nil {
 		result.DNS = n.DNS
 	}
 
@@ -743,13 +743,6 @@ func cmdAdd(args *skel.CmdArgs) error {
 	return types.PrintResult(result, cniVersion)
 }
 
-func dnsConfSet(dnsConf types.DNS) bool {
-	return dnsConf.Nameservers != nil ||
-		dnsConf.Search != nil ||
-		dnsConf.Options != nil ||
-		dnsConf.Domain != ""
-}
-
 func cmdDel(args *skel.CmdArgs) error {
 	n, _, err := loadNetConf(args.StdinData, args.Args)
 	if err != nil {

plugins/main/ptp/ptp.go

@@ -241,20 +241,13 @@ func cmdAdd(args *skel.CmdArgs) error {
 	// Only override the DNS settings in the previous result if any DNS fields
 	// were provided to the ptp plugin. This allows, for example, IPAM plugins
 	// to specify the DNS settings instead of the ptp plugin.
-	if dnsConfSet(conf.DNS) {
+	if conf.DNS != nil {
 		result.DNS = conf.DNS
 	}
 
 	return types.PrintResult(result, conf.CNIVersion)
 }
 
-func dnsConfSet(dnsConf types.DNS) bool {
-	return dnsConf.Nameservers != nil ||
-		dnsConf.Search != nil ||
-		dnsConf.Options != nil ||
-		dnsConf.Domain != ""
-}
-
 func cmdDel(args *skel.CmdArgs) error {
 	conf := NetConf{}
 	if err := json.Unmarshal(args.StdinData, &conf); err != nil {