@@ -2721,6 +2721,10 @@ definitions:

               - "default"

               - "process"

               - "hyperv"

+          Init:

+            description: "Run an init inside the container that forwards signals and reaps processes. This field is omitted if empty, and the default (as configured on the daemon) is used."

+            type: "boolean"

+            x-nullable: true

       NetworkAttachmentSpec:

         description: |

           Read-only spec type for non-swarm containers attached to swarm overlay

@@ -55,6 +55,7 @@ type ContainerSpec struct {

 	User            string                  `json:",omitempty"`

 	Groups          []string                `json:",omitempty"`

 	Privileges      *Privileges             `json:",omitempty"`

+	Init            *bool                   `json:",omitempty"`

 	StopSignal      string                  `json:",omitempty"`

 	TTY             bool                    `json:",omitempty"`

 	OpenStdin       bool                    `json:",omitempty"`

@@ -35,6 +35,7 @@ func containerSpecFromGRPC(c *swarmapi.ContainerSpec) *types.ContainerSpec {

 		Secrets:    secretReferencesFromGRPC(c.Secrets),

 		Configs:    configReferencesFromGRPC(c.Configs),

 		Isolation:  IsolationFromGRPC(c.Isolation),

+		Init:       initFromGRPC(c.Init),

 	}

 	if c.DNSConfig != nil {

@@ -119,6 +120,21 @@ func containerSpecFromGRPC(c *swarmapi.ContainerSpec) *types.ContainerSpec {

 	return containerSpec

 }

+func initFromGRPC(v *gogotypes.BoolValue) *bool {

+	if v == nil {

+		return nil

+	}

+	value := v.GetValue()

+	return &value

+}

+

+func initToGRPC(v *bool) *gogotypes.BoolValue {

+	if v == nil {

+		return nil

+	}

+	return &gogotypes.BoolValue{Value: *v}

+}

+

 func secretReferencesToGRPC(sr []*types.SecretReference) []*swarmapi.SecretReference {

 	refs := make([]*swarmapi.SecretReference, 0, len(sr))

 	for _, s := range sr {

@@ -234,6 +250,7 @@ func containerToGRPC(c *types.ContainerSpec) (*swarmapi.ContainerSpec, error) {

 		Secrets:    secretReferencesToGRPC(c.Secrets),

 		Configs:    configReferencesToGRPC(c.Configs),

 		Isolation:  isolationToGRPC(c.Isolation),

+		Init:       initToGRPC(c.Init),

 	}

 	if c.DNSConfig != nil {

@@ -172,6 +172,14 @@ func (c *containerConfig) isolation() enginecontainer.Isolation {

 	return convert.IsolationFromGRPC(c.spec().Isolation)

 }

+func (c *containerConfig) init() *bool {

+	if c.spec().Init == nil {

+		return nil

+	}

+	init := c.spec().Init.GetValue()

+	return &init

+}

+

 func (c *containerConfig) exposedPorts() map[nat.Port]struct{} {

 	exposedPorts := make(map[nat.Port]struct{})

 	if c.task.Endpoint == nil {

@@ -355,6 +363,7 @@ func (c *containerConfig) hostConfig() *enginecontainer.HostConfig {

 		Mounts:         c.mounts(),

 		ReadonlyRootfs: c.spec().ReadOnly,

 		Isolation:      c.isolation(),

+		Init:           c.init(),

 	}

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

@@ -86,6 +86,14 @@ func defaultServiceSpec() swarmtypes.ServiceSpec {

 	return spec

 }

+// ServiceWithInit sets whether the service should use init or not

+func ServiceWithInit(b *bool) func(*swarmtypes.ServiceSpec) {

+	return func(spec *swarmtypes.ServiceSpec) {

+		ensureContainerSpec(spec)

+		spec.TaskTemplate.ContainerSpec.Init = b

+	}

+}

+

 // ServiceWithImage sets the image to use for the service

 func ServiceWithImage(image string) func(*swarmtypes.ServiceSpec) {

 	return func(spec *swarmtypes.ServiceSpec) {

@@ -2,6 +2,7 @@ package service // import "github.com/docker/docker/integration/service"

 import (

 	"context"

+	"fmt"

 	"io/ioutil"

 	"testing"

 	"time"

@@ -11,11 +12,64 @@ import (

 	swarmtypes "github.com/docker/docker/api/types/swarm"

 	"github.com/docker/docker/client"

 	"github.com/docker/docker/integration/internal/swarm"

+	"github.com/docker/docker/internal/test/daemon"

 	"github.com/gotestyourself/gotestyourself/assert"

 	is "github.com/gotestyourself/gotestyourself/assert/cmp"

 	"github.com/gotestyourself/gotestyourself/poll"

 )

+func TestServiceCreateInit(t *testing.T) {

+	defer setupTest(t)()

+	t.Run("daemonInitDisabled", testServiceCreateInit(false))

+	t.Run("daemonInitEnabled", testServiceCreateInit(true))

+}

+

+func testServiceCreateInit(daemonEnabled bool) func(t *testing.T) {

+	return func(t *testing.T) {

+		var ops = []func(*daemon.Daemon){}

+

+		if daemonEnabled {

+			ops = append(ops, daemon.WithInit)

+		}

+		d := swarm.NewSwarm(t, testEnv, ops...)

+		defer d.Stop(t)

+		client := d.NewClientT(t)

+		defer client.Close()

+

+		booleanTrue := true

+		booleanFalse := false

+

+		serviceID := swarm.CreateService(t, d)

+		poll.WaitOn(t, serviceRunningTasksCount(client, serviceID, 1), swarm.ServicePoll)

+		i := inspectServiceContainer(t, client, serviceID)

+		// HostConfig.Init == nil means that it delegates to daemon configuration

+		assert.Check(t, i.HostConfig.Init == nil)

+

+		serviceID = swarm.CreateService(t, d, swarm.ServiceWithInit(&booleanTrue))

+		poll.WaitOn(t, serviceRunningTasksCount(client, serviceID, 1), swarm.ServicePoll)

+		i = inspectServiceContainer(t, client, serviceID)

+		assert.Check(t, is.Equal(true, *i.HostConfig.Init))

+

+		serviceID = swarm.CreateService(t, d, swarm.ServiceWithInit(&booleanFalse))

+		poll.WaitOn(t, serviceRunningTasksCount(client, serviceID, 1), swarm.ServicePoll)

+		i = inspectServiceContainer(t, client, serviceID)

+		assert.Check(t, is.Equal(false, *i.HostConfig.Init))

+	}

+}

+

+func inspectServiceContainer(t *testing.T, client client.APIClient, serviceID string) types.ContainerJSON {

+	t.Helper()

+	filter := filters.NewArgs()

+	filter.Add("label", fmt.Sprintf("com.docker.swarm.service.id=%s", serviceID))

+	containers, err := client.ContainerList(context.Background(), types.ContainerListOptions{Filters: filter})

+	assert.NilError(t, err)

+	assert.Check(t, is.Len(containers, 1))

+

+	i, err := client.ContainerInspect(context.Background(), containers[0].ID)

+	assert.NilError(t, err)

+	return i

+}

+

 func TestCreateServiceMultipleTimes(t *testing.T) {

 	defer setupTest(t)()

 	d := swarm.NewSwarm(t, testEnv)

@@ -66,6 +66,7 @@ type Daemon struct {

 	userlandProxy bool

 	execRoot      string

 	experimental  bool

+	init          bool

 	dockerdBinary string

 	log           logT

@@ -229,7 +230,10 @@ func (d *Daemon) StartWithLogFile(out *os.File, providedArgs ...string) error {

 		fmt.Sprintf("--userland-proxy=%t", d.userlandProxy),

 	)

 	if d.experimental {

-		args = append(args, "--experimental", "--init")

+		args = append(args, "--experimental")

+	}

+	if d.init {

+		args = append(args, "--init")

 	}

 	if !(d.UseDefaultHost || d.UseDefaultTLSHost) {

 		args = append(args, []string{"--host", d.Sock()}...)

@@ -5,6 +5,12 @@ import "github.com/docker/docker/internal/test/environment"

 // WithExperimental sets the daemon in experimental mode

 func WithExperimental(d *Daemon) {

 	d.experimental = true

+	d.init = true

+}

+

+// WithInit sets the daemon init

+func WithInit(d *Daemon) {

+	d.init = true

 }

 // WithDockerdBinary sets the dockerd binary to the specified one