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

 	"github.com/docker/distribution/reference"

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

+	registrytypes "github.com/docker/docker/api/types/registry"

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

 	"github.com/opencontainers/go-digest"

 	"golang.org/x/net/context"

@@ -33,6 +34,8 @@ func (cli *Client) ServiceCreate(ctx context.Context, service swarm.ServiceSpec,

 			if img != "" {

 				service.TaskTemplate.ContainerSpec.Image = img

 			}

+			// add platforms that are compatible with the service

+			service.TaskTemplate.Placement = updateServicePlatforms(service.TaskTemplate.Placement, distributionInspect)

 		}

 	}

 	var response types.ServiceCreateResponse

@@ -71,6 +74,22 @@ func imageWithDigestString(image string, dgst digest.Digest) string {

 	return ""

 }

+// updateServicePlatforms updates the Platforms in swarm.Placement to list

+// all compatible platforms for the service, as found in distributionInspect

+// and returns a pointer to the new or updated swarm.Placement struct

+func updateServicePlatforms(placement *swarm.Placement, distributionInspect registrytypes.DistributionInspect) *swarm.Placement {

+	if placement == nil {

+		placement = &swarm.Placement{}

+	}

+	for _, p := range distributionInspect.Platforms {

+		placement.Platforms = append(placement.Platforms, swarm.Platform{

+			Architecture: p.Architecture,

+			OS:           p.OS,

+		})

+	}

+	return placement

+}

+

 // digestWarning constructs a formatted warning string using the

 // image name that could not be pinned by digest. The formatting

 // is hardcoded, but could me made smarter in the future

@@ -10,7 +10,9 @@ import (

 	"testing"

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

+	registrytypes "github.com/docker/docker/api/types/registry"

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

+	"github.com/opencontainers/image-spec/specs-go/v1"

 	"golang.org/x/net/context"

 )

@@ -55,3 +57,55 @@ func TestServiceCreate(t *testing.T) {

 		t.Fatalf("expected `service_id`, got %s", r.ID)

 	}

 }

+

+func TestServiceCreateCompatiblePlatforms(t *testing.T) {

+	var platforms []v1.Platform

+	client := &Client{

+		client: newMockClient(func(req *http.Request) (*http.Response, error) {

+			if strings.HasPrefix(req.URL.Path, "/services/create") {

+				// platforms should have been resolved by now

+				if len(platforms) != 1 || platforms[0].Architecture != "amd64" || platforms[0].OS != "linux" {

+					return nil, fmt.Errorf("incorrect platform information")

+				}

+				b, err := json.Marshal(types.ServiceCreateResponse{

+					ID: "service_" + platforms[0].Architecture,

+				})

+				if err != nil {

+					return nil, err

+				}

+				return &http.Response{

+					StatusCode: http.StatusOK,

+					Body:       ioutil.NopCloser(bytes.NewReader(b)),

+				}, nil

+			} else if strings.HasPrefix(req.URL.Path, "/distribution/") {

+				platforms = []v1.Platform{

+					{

+						Architecture: "amd64",

+						OS:           "linux",

+					},

+				}

+				b, err := json.Marshal(registrytypes.DistributionInspect{

+					Descriptor: v1.Descriptor{},

+					Platforms:  platforms,

+				})

+				if err != nil {

+					return nil, err

+				}

+				return &http.Response{

+					StatusCode: http.StatusOK,

+					Body:       ioutil.NopCloser(bytes.NewReader(b)),

+				}, nil

+			} else {

+				return nil, fmt.Errorf("unexpected URL '%s'", req.URL.Path)

+			}

+		}),

+	}

+

+	r, err := client.ServiceCreate(context.Background(), swarm.ServiceSpec{}, types.ServiceCreateOptions{QueryRegistry: true})

+	if err != nil {

+		t.Fatal(err)

+	}

+	if r.ID != "service_amd64" {

+		t.Fatalf("expected `service_amd64`, got %s", r.ID)

+	}

+}

@@ -46,6 +46,8 @@ func (cli *Client) ServiceUpdate(ctx context.Context, serviceID string, version

 			if img != "" {

 				service.TaskTemplate.ContainerSpec.Image = img

 			}

+			// add platforms that are compatible with the service

+			service.TaskTemplate.Placement = updateServicePlatforms(service.TaskTemplate.Placement, distributionInspect)

 		}

 	}