@@ -7,6 +7,20 @@ import (

 	"github.com/docker/docker/api/types/mount"

 )

+// DNSConfig specifies DNS related configurations in resolver configuration file (resolv.conf)

+// Detailed documentation is available in:

+// http://man7.org/linux/man-pages/man5/resolv.conf.5.html

+// `nameserver`, `search`, `options` have been supported.

+// TODO: `domain` is not supported yet.

+type DNSConfig struct {

+	// Nameservers specifies the IP addresses of the name servers

+	Nameservers []string `json:",omitempty"`

+	// Search specifies the search list for host-name lookup

+	Search []string `json:",omitempty"`

+	// Options allows certain internal resolver variables to be modified

+	Options []string `json:",omitempty"`

+}

+

 // ContainerSpec represents the spec of a container.

 type ContainerSpec struct {

 	Image           string                  `json:",omitempty"`

@@ -22,4 +36,5 @@ type ContainerSpec struct {

 	Mounts          []mount.Mount           `json:",omitempty"`

 	StopGracePeriod *time.Duration          `json:",omitempty"`

 	Healthcheck     *container.HealthConfig `json:",omitempty"`

+	DNSConfig       *DNSConfig              `json:",omitempty"`

 }

@@ -41,6 +41,9 @@ func newCreateCommand(dockerCli *command.DockerCli) *cobra.Command {

 	flags.StringSliceVar(&opts.networks, flagNetwork, []string{}, "Network attachments")

 	flags.VarP(&opts.endpoint.ports, flagPublish, "p", "Publish a port as a node port")

 	flags.StringSliceVar(&opts.groups, flagGroup, []string{}, "Set one or more supplementary user groups for the container")

+	flags.Var(&opts.dns, flagDNS, "Set custom DNS servers")

+	flags.Var(&opts.dnsOptions, flagDNSOptions, "Set DNS options")

+	flags.Var(&opts.dnsSearch, flagDNSSearch, "Set custom DNS search domains")

 	flags.SetInterspersed(false)

 	return cmd

@@ -296,6 +296,9 @@ type serviceOptions struct {

 	groups          []string

 	tty             bool

 	mounts          opts.MountOpt

+	dns             opts.ListOpts

+	dnsSearch       opts.ListOpts

+	dnsOptions      opts.ListOpts

 	resources resourceOptions

 	stopGrace DurationOpt

@@ -325,7 +328,10 @@ func newServiceOptions() *serviceOptions {

 		endpoint: endpointOptions{

 			ports: opts.NewListOpts(ValidatePort),

 		},

-		logDriver: newLogDriverOptions(),

+		logDriver:  newLogDriverOptions(),

+		dns:        opts.NewListOpts(opts.ValidateIPAddress),

+		dnsOptions: opts.NewListOpts(nil),

+		dnsSearch:  opts.NewListOpts(opts.ValidateDNSSearch),

 	}

 }

@@ -358,16 +364,21 @@ func (opts *serviceOptions) ToService() (swarm.ServiceSpec, error) {

 		},

 		TaskTemplate: swarm.TaskSpec{

 			ContainerSpec: swarm.ContainerSpec{

-				Image:           opts.image,

-				Args:            opts.args,

-				Env:             currentEnv,

-				Hostname:        opts.hostname,

-				Labels:          runconfigopts.ConvertKVStringsToMap(opts.containerLabels.GetAll()),

-				Dir:             opts.workdir,

-				User:            opts.user,

-				Groups:          opts.groups,

-				TTY:             opts.tty,

-				Mounts:          opts.mounts.Value(),

+				Image:    opts.image,

+				Args:     opts.args,

+				Env:      currentEnv,

+				Hostname: opts.hostname,

+				Labels:   runconfigopts.ConvertKVStringsToMap(opts.containerLabels.GetAll()),

+				Dir:      opts.workdir,

+				User:     opts.user,

+				Groups:   opts.groups,

+				TTY:      opts.tty,

+				Mounts:   opts.mounts.Value(),

+				DNSConfig: &swarm.DNSConfig{

+					Nameservers: opts.dns.GetAll(),

+					Search:      opts.dnsSearch.GetAll(),

+					Options:     opts.dnsOptions.GetAll(),

+				},

 				StopGracePeriod: opts.stopGrace.Value(),

 			},

 			Networks:      convertNetworks(opts.networks),

@@ -463,6 +474,9 @@ const (

 	flagContainerLabel        = "container-label"

 	flagContainerLabelRemove  = "container-label-rm"

 	flagContainerLabelAdd     = "container-label-add"

+	flagDNS                   = "dns"

+	flagDNSOptions            = "dns-opt"

+	flagDNSSearch             = "dns-search"

 	flagEndpointMode          = "endpoint-mode"

 	flagHostname              = "hostname"

 	flagEnv                   = "env"

@@ -25,6 +25,14 @@ func containerSpecFromGRPC(c *swarmapi.ContainerSpec) types.ContainerSpec {

 		TTY:      c.TTY,

 	}

+	if c.DNSConfig != nil {

+		containerSpec.DNSConfig = &types.DNSConfig{

+			Nameservers: c.DNSConfig.Nameservers,

+			Search:      c.DNSConfig.Search,

+			Options:     c.DNSConfig.Options,

+		}

+	}

+

 	// Mounts

 	for _, m := range c.Mounts {

 		mount := mounttypes.Mount{

@@ -81,6 +89,14 @@ func containerToGRPC(c types.ContainerSpec) (*swarmapi.ContainerSpec, error) {

 		TTY:      c.TTY,

 	}

+	if c.DNSConfig != nil {

+		containerSpec.DNSConfig = &swarmapi.ContainerSpec_DNSConfig{

+			Nameservers: c.DNSConfig.Nameservers,

+			Search:      c.DNSConfig.Search,

+			Options:     c.DNSConfig.Options,

+		}

+	}

+

 	if c.StopGracePeriod != nil {

 		containerSpec.StopGracePeriod = ptypes.DurationProto(*c.StopGracePeriod)

 	}

@@ -327,6 +327,12 @@ func (c *containerConfig) hostConfig() *enginecontainer.HostConfig {

 		GroupAdd:  c.spec().Groups,

 	}

+	if c.spec().DNSConfig != nil {

+		hc.DNS = c.spec().DNSConfig.Nameservers

+		hc.DNSSearch = c.spec().DNSConfig.Search

+		hc.DNSOptions = c.spec().DNSConfig.Options

+	}

+

 	if c.task.LogDriver != nil {

 		hc.LogConfig = enginecontainer.LogConfig{

 			Type:   c.task.LogDriver.Name,

@@ -23,6 +23,9 @@ Create a new service

 Options:

       --constraint value                 Placement constraints (default [])

       --container-label value            Service container labels (default [])

+      --dns list                         Set custom DNS servers (default [])

+      --dns-opt list                     Set DNS options (default [])

+      --dns-search list                  Set custom DNS search domains (default [])

       --endpoint-mode string             Endpoint mode (vip or dnsrr)

   -e, --env value                        Set environment variables (default [])

       --env-file value                   Read in a file of environment variables (default [])

@@ -789,3 +789,30 @@ func (s *DockerSwarmSuite) TestSwarmServiceTTYUpdate(c *check.C) {

 	c.Assert(err, checker.IsNil)

 	c.Assert(strings.TrimSpace(out), checker.Equals, "true")

 }

+

+func (s *DockerSwarmSuite) TestDNSConfig(c *check.C) {

+	d := s.AddDaemon(c, true, true)

+

+	// Create a service

+	name := "top"

+	_, err := d.Cmd("service", "create", "--name", name, "--dns=1.2.3.4", "--dns-search=example.com", "--dns-opt=timeout:3", "busybox", "top")

+	c.Assert(err, checker.IsNil)

+

+	// Make sure task has been deployed.

+	waitAndAssert(c, defaultReconciliationTimeout, d.checkActiveContainerCount, checker.Equals, 1)

+

+	// We need to get the container id.

+	out, err := d.Cmd("ps", "-a", "-q", "--no-trunc")

+	c.Assert(err, checker.IsNil)

+	id := strings.TrimSpace(out)

+

+	// Compare against expected output.

+	expectedOutput1 := "nameserver 1.2.3.4"

+	expectedOutput2 := "search example.com"

+	expectedOutput3 := "options timeout:3"

+	out, err = d.Cmd("exec", id, "cat", "/etc/resolv.conf")

+	c.Assert(err, checker.IsNil)

+	c.Assert(out, checker.Contains, expectedOutput1, check.Commentf("Expected '%s', but got %q", expectedOutput1, out))

+	c.Assert(out, checker.Contains, expectedOutput2, check.Commentf("Expected '%s', but got %q", expectedOutput2, out))

+	c.Assert(out, checker.Contains, expectedOutput3, check.Commentf("Expected '%s', but got %q", expectedOutput3, out))

+}