Add --init option to `docker service create`

Signed-off-by: Timothy Higinbottom <timhigins@gmail.com>
Signed-off-by: Vincent Demeester <vincent@sbr.pm>

cli/command/formatter/service.go

@@ -85,6 +85,9 @@ ContainerSpec:
 {{- if .ContainerWorkDir }}
  Dir:		{{ .ContainerWorkDir }}
 {{- end -}}
+{{- if .HasContainerInit }}
+ Init:		{{ .ContainerInit }}
+{{- end -}}
 {{- if .ContainerUser }}
  User: {{ .ContainerUser }}
 {{- end }}
@@ -372,6 +375,14 @@ func (ctx *serviceInspectContext) ContainerUser() string {
 	return ctx.Service.Spec.TaskTemplate.ContainerSpec.User
 }
 
+func (ctx *serviceInspectContext) HasContainerInit() bool {
+	return ctx.Service.Spec.TaskTemplate.ContainerSpec.Init != nil
+}
+
+func (ctx *serviceInspectContext) ContainerInit() bool {
+	return *ctx.Service.Spec.TaskTemplate.ContainerSpec.Init
+}
+
 func (ctx *serviceInspectContext) ContainerMounts() []mounttypes.Mount {
 	return ctx.Service.Spec.TaskTemplate.ContainerSpec.Mounts
 }

cli/command/service/create.go

@@ -58,6 +58,8 @@ func newCreateCommand(dockerCli command.Cli) *cobra.Command {
 	flags.SetAnnotation(flagDNSSearch, "version", []string{"1.25"})
 	flags.Var(&opts.hosts, flagHost, "Set one or more custom host-to-IP mappings (host:ip)")
 	flags.SetAnnotation(flagHost, "version", []string{"1.25"})
+	flags.BoolVar(&opts.init, flagInit, false, "Use an init inside each service container to forward signals and reap processes")
+	flags.SetAnnotation(flagInit, "version", []string{"1.37"})
 
 	flags.Var(cliopts.NewListOptsRef(&opts.resources.resGenericResources, ValidateSingleGenericResource), "generic-resource", "User defined resources")
 	flags.SetAnnotation(flagHostAdd, "version", []string{"1.32"})

cli/command/service/opts.go

@@ -480,6 +480,7 @@ type serviceOptions struct {
 	user            string
 	groups          opts.ListOpts
 	credentialSpec  credentialSpecOpt
+	init            bool
 	stopSignal      string
 	tty             bool
 	readOnly        bool
@@ -624,6 +625,7 @@ func (options *serviceOptions) ToService(ctx context.Context, apiClient client.N
 				TTY:        options.tty,
 				ReadOnly:   options.readOnly,
 				Mounts:     options.mounts.Value(),
+				Init:       &options.init,
 				DNSConfig: &swarm.DNSConfig{
 					Nameservers: options.dns.GetAll(),
 					Search:      options.dnsSearch.GetAll(),
@@ -875,6 +877,7 @@ const (
 	flagRollbackMonitor         = "rollback-monitor"
 	flagRollbackOrder           = "rollback-order"
 	flagRollbackParallelism     = "rollback-parallelism"
+	flagInit                    = "init"
 	flagStopGracePeriod         = "stop-grace-period"
 	flagStopSignal              = "stop-signal"
 	flagTTY                     = "tty"

cli/command/service/update.go

@@ -94,6 +94,8 @@ func newUpdateCommand(dockerCli command.Cli) *cobra.Command {
 	flags.SetAnnotation(flagDNSSearchAdd, "version", []string{"1.25"})
 	flags.Var(&options.hosts, flagHostAdd, "Add a custom host-to-IP mapping (host:ip)")
 	flags.SetAnnotation(flagHostAdd, "version", []string{"1.25"})
+	flags.BoolVar(&options.init, flagInit, false, "Use an init inside each service container to forward signals and reap processes")
+	flags.SetAnnotation(flagInit, "version", []string{"1.37"})
 
 	// Add needs parsing, Remove only needs the key
 	flags.Var(newListOptsVar(), flagGenericResourcesRemove, "Remove a Generic resource")
@@ -235,6 +237,12 @@ func runUpdate(dockerCli command.Cli, flags *pflag.FlagSet, options *serviceOpti
 
 // nolint: gocyclo
 func updateService(ctx context.Context, apiClient client.NetworkAPIClient, flags *pflag.FlagSet, spec *swarm.ServiceSpec) error {
+	updateBoolPtr := func(flag string, field **bool) {
+		if flags.Changed(flag) {
+			b, _ := flags.GetBool(flag)
+			*field = &b
+		}
+	}
 	updateString := func(flag string, field *string) {
 		if flags.Changed(flag) {
 			*field, _ = flags.GetString(flag)
@@ -306,6 +314,7 @@ func updateService(ctx context.Context, apiClient client.NetworkAPIClient, flags
 	updateString(flagWorkdir, &cspec.Dir)
 	updateString(flagUser, &cspec.User)
 	updateString(flagHostname, &cspec.Hostname)
+	updateBoolPtr(flagInit, &cspec.Init)
 	if err := updateIsolation(flagIsolation, &cspec.Isolation); err != nil {
 		return err
 	}

cli/command/service/update_test.go

@@ -547,6 +547,32 @@ func TestUpdateReadOnly(t *testing.T) {
 	assert.Check(t, !cspec.ReadOnly)
 }
 
+func TestUpdateInit(t *testing.T) {
+	spec := &swarm.ServiceSpec{
+		TaskTemplate: swarm.TaskSpec{
+			ContainerSpec: &swarm.ContainerSpec{},
+		},
+	}
+	cspec := spec.TaskTemplate.ContainerSpec
+
+	// Update with --init=true
+	flags := newUpdateCommand(nil).Flags()
+	flags.Set("init", "true")
+	updateService(nil, nil, flags, spec)
+	assert.Check(t, is.Equal(true, *cspec.Init))
+
+	// Update without --init, no change
+	flags = newUpdateCommand(nil).Flags()
+	updateService(nil, nil, flags, spec)
+	assert.Check(t, is.Equal(true, *cspec.Init))
+
+	// Update with --init=false
+	flags = newUpdateCommand(nil).Flags()
+	flags.Set("init", "false")
+	updateService(nil, nil, flags, spec)
+	assert.Check(t, is.Equal(false, *cspec.Init))
+}
+
 func TestUpdateStopSignal(t *testing.T) {
 	spec := &swarm.ServiceSpec{
 		TaskTemplate: swarm.TaskSpec{

docs/reference/commandline/service_create.md

@@ -43,6 +43,7 @@ Options:
       --help                               Print usage
       --host list                          Set one or more custom host-to-IP mappings (host:ip)
       --hostname string                    Container hostname
+      --init bool                          Use an init inside each service container to forward signals and reap processes
       --isolation string                   Service container isolation mode
   -l, --label list                         Service labels
       --limit-cpu decimal                  Limit CPUs

docs/reference/commandline/service_update.md

@@ -54,6 +54,7 @@ Options:
       --host-add list                      Add a custom host-to-IP mapping (host:ip)
       --host-rm list                       Remove a custom host-to-IP mapping (host:ip)
       --hostname string                    Container hostname
+      --init bool                          Use an init inside each service container to forward signals and reap processes
       --image string                       Service image tag
       --isolation string                   Service container isolation mode
       --label-add list                     Add or update a service label