@@ -96,7 +96,8 @@ RUN /download-frozen-image-v2.sh /build \

         busybox:latest@sha256:95cf004f559831017cdf4628aaf1bb30133677be8702a8c5f2994629f637a209 \

         busybox:glibc@sha256:1f81263701cddf6402afe9f33fca0266d9fff379e59b1748f33d3072da71ee85 \

         debian:buster@sha256:46d659005ca1151087efa997f1039ae45a7bf7a2cbbe2d17d3dcbda632a3ee9a \

-        hello-world:latest@sha256:d58e752213a51785838f9eed2b7a498ffa1cb3aa7f946dda11af39286c3db9a9

+        hello-world:latest@sha256:d58e752213a51785838f9eed2b7a498ffa1cb3aa7f946dda11af39286c3db9a9 \

+        arm32v7/hello-world:latest@sha256:50b8560ad574c779908da71f7ce370c0a2471c098d44d1c8f6b513c5a55eeeb1

 # See also ensureFrozenImagesLinux() in "integration-cli/fixtures_linux_daemon_test.go" (which needs to be updated when adding images to this list)

 FROM base AS cross-false

@@ -510,17 +510,6 @@ func (s *containerRouter) postContainersCreate(ctx context.Context, w http.Respo

 			}

 			platform = &p

 		}

-		defaultPlatform := platforms.DefaultSpec()

-		if platform == nil {

-			platform = &defaultPlatform

-		}

-		if platform.OS == "" {

-			platform.OS = defaultPlatform.OS

-		}

-		if platform.Architecture == "" {

-			platform.Architecture = defaultPlatform.Architecture

-			platform.Variant = defaultPlatform.Variant

-		}

 	}

 	if hostConfig != nil && hostConfig.PidsLimit != nil && *hostConfig.PidsLimit <= 0 {

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

 	"strings"

 	"time"

+	"github.com/containerd/containerd/platforms"

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

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

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

@@ -16,6 +17,7 @@ import (

 	"github.com/docker/docker/pkg/idtools"

 	"github.com/docker/docker/pkg/system"

 	"github.com/docker/docker/runconfig"

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

 	"github.com/opencontainers/selinux/go-selinux"

 	"github.com/pkg/errors"

 	"github.com/sirupsen/logrus"

@@ -59,8 +61,10 @@ func (daemon *Daemon) containerCreate(opts createOpts) (containertypes.Container

 	}

 	os := runtime.GOOS

+	var img *image.Image

 	if opts.params.Config.Image != "" {

-		img, err := daemon.imageService.GetImage(opts.params.Config.Image, opts.params.Platform)

+		var err error

+		img, err = daemon.imageService.GetImage(opts.params.Config.Image, opts.params.Platform)

 		if err == nil {

 			os = img.OS

 		}

@@ -77,6 +81,19 @@ func (daemon *Daemon) containerCreate(opts createOpts) (containertypes.Container

 		return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, errdefs.InvalidParameter(err)

 	}

+	if img != nil && opts.params.Platform == nil {

+		p := platforms.DefaultSpec()

+		imgPlat := v1.Platform{

+			OS:           img.OS,

+			Architecture: img.Architecture,

+			Variant:      img.Variant,

+		}

+

+		if !platforms.Only(p).Match(imgPlat) {

+			warnings = append(warnings, fmt.Sprintf("The requested image's platform (%s) does not match the detected host platform (%s) and no specific platform was requested", platforms.Format(imgPlat), platforms.Format(p)))

+		}

+	}

+

 	err = verifyNetworkingConfig(opts.params.NetworkingConfig)

 	if err != nil {

 		return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, errdefs.InvalidParameter(err)

@@ -3,6 +3,7 @@ package images // import "github.com/docker/docker/daemon/images"

 import (

 	"fmt"

+	"github.com/containerd/containerd/platforms"

 	"github.com/pkg/errors"

 	"github.com/docker/distribution/reference"

@@ -34,30 +35,24 @@ func (i *ImageService) GetImage(refOrID string, platform *specs.Platform) (retIm

 			return

 		}

-		// This allows us to tell clients that we don't have the image they asked for

-		// Where this gets hairy is the image store does not currently support multi-arch images, e.g.:

-		//   An image `foo` may have a multi-arch manifest, but the image store only fetches the image for a specific platform

-		//   The image store does not store the manifest list and image tags are assigned to architecture specific images.

-		//   So we can have a `foo` image that is amd64 but the user requested armv7. If the user looks at the list of images.

-		//   This may be confusing.

-		//   The alternative to this is to return a errdefs.Conflict error with a helpful message, but clients will not be

-		//   able to automatically tell what causes the conflict.

-		if retImg.OS != platform.OS {

-			retErr = errdefs.NotFound(errors.Errorf("image with reference %s was found but does not match the specified OS platform: wanted: %s, actual: %s", refOrID, platform.OS, retImg.OS))

-			retImg = nil

-			return

-		}

-		if retImg.Architecture != platform.Architecture {

-			retErr = errdefs.NotFound(errors.Errorf("image with reference %s was found but does not match the specified platform cpu architecture: wanted: %s, actual: %s", refOrID, platform.Architecture, retImg.Architecture))

-			retImg = nil

-			return

+		imgPlat := specs.Platform{

+			OS:           retImg.OS,

+			Architecture: retImg.Architecture,

+			Variant:      retImg.Variant,

 		}

-

-		// Only validate variant if retImg has a variant set.

-		// The image variant may not be set since it's a newer field.

-		if platform.Variant != "" && retImg.Variant != "" && retImg.Variant != platform.Variant {

-			retErr = errdefs.NotFound(errors.Errorf("image with reference %s was found but does not match the specified platform cpu architecture variant: wanted: %s, actual: %s", refOrID, platform.Variant, retImg.Variant))

-			retImg = nil

+		p := *platform

+		// Note that `platforms.Only` will fuzzy match this for us

+		// For example: an armv6 image will run just fine an an armv7 CPU, without emulation or anything.

+		if !platforms.Only(p).Match(imgPlat) {

+			// This allows us to tell clients that we don't have the image they asked for

+			// Where this gets hairy is the image store does not currently support multi-arch images, e.g.:

+			//   An image `foo` may have a multi-arch manifest, but the image store only fetches the image for a specific platform

+			//   The image store does not store the manifest list and image tags are assigned to architecture specific images.

+			//   So we can have a `foo` image that is amd64 but the user requested armv7. If the user looks at the list of images.

+			//   This may be confusing.

+			//   The alternative to this is to return a errdefs.Conflict error with a helpful message, but clients will not be

+			//   able to automatically tell what causes the conflict.

+			retErr = errdefs.NotFound(errors.Errorf("image with reference %s was found but does not match the specified platform: wanted %s, actual: %s", refOrID, platforms.Format(p), platforms.Format(imgPlat)))

 			return

 		}

 	}()

@@ -508,3 +508,23 @@ func TestCreateVolumesFromNonExistingContainer(t *testing.T) {

 	)

 	assert.Check(t, errdefs.IsInvalidParameter(err))

 }

+

+// Test that we can create a container from an image that is for a different platform even if a platform was not specified

+// This is for the regression detailed here: https://github.com/moby/moby/issues/41552

+func TestCreatePlatformSpecificImageNoPlatform(t *testing.T) {

+	defer setupTest(t)()

+

+	skip.If(t, testEnv.DaemonInfo.Architecture == "arm", "test only makes sense to run on non-arm systems")

+	skip.If(t, testEnv.OSType != "linux", "test image is only available on linux")

+	cli := testEnv.APIClient()

+

+	_, err := cli.ContainerCreate(

+		context.Background(),

+		&container.Config{Image: "arm32v7/hello-world"},

+		&container.HostConfig{},

+		nil,

+		nil,

+		"",

+	)

+	assert.NilError(t, err)

+}