Added support for dns-search and fixes #30102

Signed-off-by: msabansal <sabansal@microsoft.com>

daemon/container_operations.go

@@ -32,12 +32,22 @@ var (
 	getPortMapInfo    = container.GetSandboxPortMapInfo
 )
 
+func (daemon *Daemon) getDNSSearchSettings(container *container.Container) []string {
+	if len(container.HostConfig.DNSSearch) > 0 {
+		return container.HostConfig.DNSSearch
+	}
+
+	if len(daemon.configStore.DNSSearch) > 0 {
+		return daemon.configStore.DNSSearch
+	}
+
+	return nil
+}
 func (daemon *Daemon) buildSandboxOptions(container *container.Container) ([]libnetwork.SandboxOption, error) {
 	var (
 		sboxOptions []libnetwork.SandboxOption
 		err         error
 		dns         []string
-		dnsSearch   []string
 		dnsOptions  []string
 		bindings    = make(nat.PortMap)
 		pbList      []types.PortBinding
@@ -78,11 +88,7 @@ func (daemon *Daemon) buildSandboxOptions(container *container.Container) ([]lib
 		sboxOptions = append(sboxOptions, libnetwork.OptionDNS(d))
 	}
 
-	if len(container.HostConfig.DNSSearch) > 0 {
-		dnsSearch = container.HostConfig.DNSSearch
-	} else if len(daemon.configStore.DNSSearch) > 0 {
-		dnsSearch = daemon.configStore.DNSSearch
-	}
+	dnsSearch := daemon.getDNSSearchSettings(container)
 
 	for _, ds := range dnsSearch {
 		sboxOptions = append(sboxOptions, libnetwork.OptionDNSSearch(ds))

daemon/daemon_windows.go

@@ -339,8 +339,10 @@ func (daemon *Daemon) initNetworkController(config *Config, activeSandboxes map[
 		name := v.Name
 
 		// If there is no nat network create one from the first NAT network
-		// encountered
-		if !defaultNetworkExists && runconfig.DefaultDaemonNetworkMode() == containertypes.NetworkMode(strings.ToLower(v.Type)) {
+		// encountered if it doesn't already exist
+		if !defaultNetworkExists &&
+			runconfig.DefaultDaemonNetworkMode() == containertypes.NetworkMode(strings.ToLower(v.Type)) &&
+			n == nil {
 			name = runconfig.DefaultDaemonNetworkMode().NetworkName()
 			defaultNetworkExists = true
 		}

daemon/start_windows.go

@@ -9,6 +9,7 @@ import (
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/layer"
 	"github.com/docker/docker/libcontainerd"
+	"github.com/docker/docker/pkg/system"
 	"golang.org/x/sys/windows/registry"
 )
 
@@ -30,6 +31,14 @@ func (daemon *Daemon) getLibcontainerdCreateOptions(container *container.Contain
 		hvOpts.IsHyperV = container.HostConfig.Isolation.IsHyperV()
 	}
 
+	dnsSearch := daemon.getDNSSearchSettings(container)
+	if dnsSearch != nil {
+		osv := system.GetOSVersion()
+		if osv.Build < 14997 {
+			return nil, fmt.Errorf("dns-search option is not supported on the current platform")
+		}
+	}
+
 	// Generate the layer folder of the layer options
 	layerOpts := &libcontainerd.LayerOption{}
 	m, err := container.RWLayer.Metadata()
@@ -149,7 +158,11 @@ func (daemon *Daemon) getLibcontainerdCreateOptions(container *container.Contain
 	createOptions = append(createOptions, hvOpts)
 	createOptions = append(createOptions, layerOpts)
 	if epList != nil {
-		createOptions = append(createOptions, &libcontainerd.NetworkEndpointsOption{Endpoints: epList, AllowUnqualifiedDNSQuery: AllowUnqualifiedDNSQuery})
+		createOptions = append(createOptions, &libcontainerd.NetworkEndpointsOption{
+			Endpoints:                epList,
+			AllowUnqualifiedDNSQuery: AllowUnqualifiedDNSQuery,
+			DNSSearchList:            dnsSearch,
+		})
 	}
 
 	return createOptions, nil

libcontainerd/client_windows.go

@@ -90,6 +90,7 @@ const defaultOwner = "docker"
 //	"SandboxPath": "C:\\\\control\\\\windowsfilter",
 //	"HvPartition": true,
 //	"EndpointList": ["e1bb1e61-d56f-405e-b75d-fd520cefa0cb"],
+//	"DNSSearchList": "a.com,b.com,c.com",
 //	"HvRuntime": {
 //		"ImagePath": "C:\\\\control\\\\windowsfilter\\\\65bf96e5760a09edf1790cb229e2dfb2dbd0fcdc0bf7451bae099106bfbfea0c\\\\UtilityVM"
 //	},
@@ -166,6 +167,9 @@ func (clnt *client) Create(containerID string, checkpoint string, checkpointDir
 		if n, ok := option.(*NetworkEndpointsOption); ok {
 			configuration.EndpointList = n.Endpoints
 			configuration.AllowUnqualifiedDNSQuery = n.AllowUnqualifiedDNSQuery
+			if n.DNSSearchList != nil {
+				configuration.DNSSearchList = strings.Join(n.DNSSearchList, ",")
+			}
 			continue
 		}
 		if c, ok := option.(*CredentialsOption); ok {

libcontainerd/types_windows.go

@@ -59,6 +59,7 @@ type LayerOption struct {
 type NetworkEndpointsOption struct {
 	Endpoints                []string
 	AllowUnqualifiedDNSQuery bool
+	DNSSearchList            []string
 }
 
 // CredentialsOption is a CreateOption that indicates the credentials from