@@ -32,6 +32,7 @@ func newCreateCommand(dockerCli *command.DockerCli) *cobra.Command {

 	flags.VarP(&opts.labels, flagLabel, "l", "Service labels")

 	flags.Var(&opts.containerLabels, flagContainerLabel, "Container labels")

 	flags.VarP(&opts.env, flagEnv, "e", "Set environment variables")

+	flags.Var(&opts.envFile, flagEnvFile, "Read in a file of environment variables")

 	flags.Var(&opts.mounts, flagMount, "Attach a mount to the service")

 	flags.StringSliceVar(&opts.constraints, flagConstraint, []string{}, "Placement constraints")

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

@@ -395,6 +395,7 @@ type serviceOptions struct {

 	image           string

 	args            []string

 	env             opts.ListOpts

+	envFile         opts.ListOpts

 	workdir         string

 	user            string

 	groups          []string

@@ -422,6 +423,7 @@ func newServiceOptions() *serviceOptions {

 		labels:          opts.NewListOpts(runconfigopts.ValidateEnv),

 		containerLabels: opts.NewListOpts(runconfigopts.ValidateEnv),

 		env:             opts.NewListOpts(runconfigopts.ValidateEnv),

+		envFile:         opts.NewListOpts(nil),

 		endpoint: endpointOptions{

 			ports: opts.NewListOpts(ValidatePort),

 		},

@@ -432,6 +434,25 @@ func newServiceOptions() *serviceOptions {

 func (opts *serviceOptions) ToService() (swarm.ServiceSpec, error) {

 	var service swarm.ServiceSpec

+	envVariables, err := runconfigopts.ReadKVStrings(opts.envFile.GetAll(), opts.env.GetAll())

+	if err != nil {

+		return service, err

+	}

+

+	currentEnv := make([]string, 0, len(envVariables))

+	for _, env := range envVariables { // need to process each var, in order

+		k := strings.SplitN(env, "=", 2)[0]

+		for i, current := range currentEnv { // remove duplicates

+			if current == env {

+				continue // no update required, may hide this behind flag to preserve order of envVariables

+			}

+			if strings.HasPrefix(current, k+"=") {

+				currentEnv = append(currentEnv[:i], currentEnv[i+1:]...)

+			}

+		}

+		currentEnv = append(currentEnv, env)

+	}

+

 	service = swarm.ServiceSpec{

 		Annotations: swarm.Annotations{

 			Name:   opts.name,

@@ -441,7 +462,7 @@ func (opts *serviceOptions) ToService() (swarm.ServiceSpec, error) {

 			ContainerSpec: swarm.ContainerSpec{

 				Image:           opts.image,

 				Args:            opts.args,

-				Env:             opts.env.GetAll(),

+				Env:             currentEnv,

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

 				Dir:             opts.workdir,

 				User:            opts.user,

@@ -532,6 +553,7 @@ const (

 	flagContainerLabelAdd     = "container-label-add"

 	flagEndpointMode          = "endpoint-mode"

 	flagEnv                   = "env"

+	flagEnvFile               = "env-file"

 	flagEnvRemove             = "env-rm"

 	flagEnvAdd                = "env-add"

 	flagGroupAdd              = "group-add"

@@ -25,6 +25,7 @@ Options:

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

       --group-add value                  Add additional user groups to the container (default [])

       --help                             Print usage

   -l, --label value                      Service labels (default [])

@@ -9,6 +9,7 @@ import (

 	"net/http"

 	"net/http/httptest"

 	"os"

+	"path/filepath"

 	"strings"

 	"time"

@@ -568,3 +569,22 @@ func (s *DockerSwarmSuite) TestSwarmNetworkPlugin(c *check.C) {

 	c.Assert(err, checker.IsNil)

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

 }

+

+// Test case for #24712

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

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

+

+	path := filepath.Join(d.folder, "env.txt")

+	err := ioutil.WriteFile(path, []byte("VAR1=A\nVAR2=A\n"), 0644)

+	c.Assert(err, checker.IsNil)

+

+	name := "worker"

+	out, err := d.Cmd("service", "create", "--env-file", path, "--env", "VAR1=B", "--env", "VAR1=C", "--env", "VAR2=", "--env", "VAR2", "--name", name, "busybox", "top")

+	c.Assert(err, checker.IsNil)

+	c.Assert(strings.TrimSpace(out), checker.Not(checker.Equals), "")

+

+	// The complete env is [VAR1=A VAR2=A VAR1=B VAR1=C VAR2= VAR2] and duplicates will be removed => [VAR1=C VAR2]

+	out, err = d.Cmd("inspect", "--format", "{{ .Spec.TaskTemplate.ContainerSpec.Env }}", name)

+	c.Assert(err, checker.IsNil)

+	c.Assert(out, checker.Contains, "[VAR1=C VAR2]")

+}

@@ -427,13 +427,13 @@ func Parse(flags *pflag.FlagSet, copts *ContainerOptions) (*container.Config, *c

 	}

 	// collect all the environment variables for the container

-	envVariables, err := readKVStrings(copts.envFile.GetAll(), copts.env.GetAll())

+	envVariables, err := ReadKVStrings(copts.envFile.GetAll(), copts.env.GetAll())

 	if err != nil {

 		return nil, nil, nil, err

 	}

 	// collect all the labels for the container

-	labels, err := readKVStrings(copts.labelsFile.GetAll(), copts.labels.GetAll())

+	labels, err := ReadKVStrings(copts.labelsFile.GetAll(), copts.labels.GetAll())

 	if err != nil {

 		return nil, nil, nil, err

 	}

@@ -663,9 +663,9 @@ func Parse(flags *pflag.FlagSet, copts *ContainerOptions) (*container.Config, *c

 	return config, hostConfig, networkingConfig, nil

 }

-// reads a file of line terminated key=value pairs, and overrides any keys

+// ReadKVStrings reads a file of line terminated key=value pairs, and overrides any keys

 // present in the file with additional pairs specified in the override parameter

-func readKVStrings(files []string, override []string) ([]string, error) {

+func ReadKVStrings(files []string, override []string) ([]string, error) {

 	envVariables := []string{}

 	for _, ef := range files {

 		parsedVars, err := ParseEnvFile(ef)