@@ -11,14 +11,12 @@ import (

 	"net/http"

 	"os"

 	"path/filepath"

-	"regexp"

 	"runtime"

 	"strings"

 	"testing"

 	"time"

 	cerrdefs "github.com/containerd/errdefs"

-	dconfig "github.com/docker/docker/daemon/config"

 	"github.com/docker/docker/daemon/volume"

 	"github.com/docker/docker/integration-cli/cli"

 	"github.com/docker/docker/integration-cli/cli/build"

@@ -1142,110 +1140,6 @@ func (s *DockerAPISuite) TestPostContainersCreateWithWrongCpusetValues(c *testin

 	assert.ErrorContains(c, err, expected)

 }

-func (s *DockerAPISuite) TestPostContainersCreateShmSizeNegative(c *testing.T) {

-	// ShmSize is not supported on Windows

-	testRequires(c, DaemonIsLinux)

-	config := container.Config{

-		Image: "busybox",

-	}

-	hostConfig := container.HostConfig{

-		ShmSize: -1,

-	}

-

-	apiClient, err := client.NewClientWithOpts(client.FromEnv)

-	assert.NilError(c, err)

-	defer apiClient.Close()

-

-	_, err = apiClient.ContainerCreate(testutil.GetContext(c), &config, &hostConfig, &network.NetworkingConfig{}, nil, "")

-	assert.ErrorContains(c, err, "SHM size can not be less than 0")

-}

-

-func (s *DockerAPISuite) TestPostContainersCreateShmSizeHostConfigOmitted(c *testing.T) {

-	// ShmSize is not supported on Windows

-	testRequires(c, DaemonIsLinux)

-

-	config := container.Config{

-		Image: "busybox",

-		Cmd:   []string{"mount"},

-	}

-

-	apiClient, err := client.NewClientWithOpts(client.FromEnv)

-	assert.NilError(c, err)

-	defer apiClient.Close()

-

-	ctr, err := apiClient.ContainerCreate(testutil.GetContext(c), &config, &container.HostConfig{}, &network.NetworkingConfig{}, nil, "")

-	assert.NilError(c, err)

-

-	containerJSON, err := apiClient.ContainerInspect(testutil.GetContext(c), ctr.ID)

-	assert.NilError(c, err)

-

-	assert.Equal(c, containerJSON.HostConfig.ShmSize, dconfig.DefaultShmSize)

-

-	out := cli.DockerCmd(c, "start", "-i", containerJSON.ID).Combined()

-	shmRegexp := regexp.MustCompile(`shm on /dev/shm type tmpfs(.*)size=65536k`)

-	if !shmRegexp.MatchString(out) {

-		c.Fatalf("Expected shm of 64MB in mount command, got %v", out)

-	}

-}

-

-func (s *DockerAPISuite) TestPostContainersCreateShmSizeOmitted(c *testing.T) {

-	// ShmSize is not supported on Windows

-	testRequires(c, DaemonIsLinux)

-	config := container.Config{

-		Image: "busybox",

-		Cmd:   []string{"mount"},

-	}

-

-	apiClient, err := client.NewClientWithOpts(client.FromEnv)

-	assert.NilError(c, err)

-	defer apiClient.Close()

-

-	ctr, err := apiClient.ContainerCreate(testutil.GetContext(c), &config, &container.HostConfig{}, &network.NetworkingConfig{}, nil, "")

-	assert.NilError(c, err)

-

-	containerJSON, err := apiClient.ContainerInspect(testutil.GetContext(c), ctr.ID)

-	assert.NilError(c, err)

-

-	assert.Equal(c, containerJSON.HostConfig.ShmSize, int64(67108864))

-

-	out := cli.DockerCmd(c, "start", "-i", containerJSON.ID).Combined()

-	shmRegexp := regexp.MustCompile(`shm on /dev/shm type tmpfs(.*)size=65536k`)

-	if !shmRegexp.MatchString(out) {

-		c.Fatalf("Expected shm of 64MB in mount command, got %v", out)

-	}

-}

-

-func (s *DockerAPISuite) TestPostContainersCreateWithShmSize(c *testing.T) {

-	// ShmSize is not supported on Windows

-	testRequires(c, DaemonIsLinux)

-	config := container.Config{

-		Image: "busybox",

-		Cmd:   []string{"mount"},

-	}

-

-	hostConfig := container.HostConfig{

-		ShmSize: 1073741824,

-	}

-

-	apiClient, err := client.NewClientWithOpts(client.FromEnv)

-	assert.NilError(c, err)

-	defer apiClient.Close()

-

-	ctr, err := apiClient.ContainerCreate(testutil.GetContext(c), &config, &hostConfig, &network.NetworkingConfig{}, nil, "")

-	assert.NilError(c, err)

-

-	containerJSON, err := apiClient.ContainerInspect(testutil.GetContext(c), ctr.ID)

-	assert.NilError(c, err)

-

-	assert.Equal(c, containerJSON.HostConfig.ShmSize, int64(1073741824))

-

-	out := cli.DockerCmd(c, "start", "-i", containerJSON.ID).Combined()

-	shmRegex := regexp.MustCompile(`shm on /dev/shm type tmpfs(.*)size=1048576k`)

-	if !shmRegex.MatchString(out) {

-		c.Fatalf("Expected shm of 1GB in mount command, got %v", out)

-	}

-}

-

 func (s *DockerAPISuite) TestPostContainersCreateMemorySwappinessHostConfigOmitted(c *testing.T) {

 	// Swappiness is not supported on Windows

 	testRequires(c, DaemonIsLinux)

@@ -9,10 +9,12 @@ import (

 	"strings"

 	"testing"

+	cerrdefs "github.com/containerd/errdefs"

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

 	net "github.com/docker/docker/integration/internal/network"

 	"github.com/docker/docker/testutil"

 	"github.com/docker/docker/testutil/daemon"

+	"github.com/docker/go-units"

 	"github.com/moby/moby/api/stdcopy"

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

 	"github.com/moby/moby/api/types/versions"

@@ -457,8 +459,8 @@ func TestCgroupRW(t *testing.T) {

 	}

 	for _, tc := range testCases {

 		t.Run(tc.name, func(t *testing.T) {

-			config := container.NewTestConfig(tc.ops...)

-			resp, err := container.CreateFromConfig(ctx, apiClient, config)

+			cfg := container.NewTestConfig(tc.ops...)

+			resp, err := container.CreateFromConfig(ctx, apiClient, cfg)

 			if err != nil {

 				assert.Equal(t, tc.expectedErrMsg, err.Error())

 				return

@@ -488,3 +490,79 @@ func TestCgroupRW(t *testing.T) {

 		})

 	}

 }

+

+func TestContainerShmSize(t *testing.T) {

+	ctx := setupTest(t)

+

+	const defaultSize = "1000k"

+	defaultSizeBytes, err := units.RAMInBytes(defaultSize)

+	assert.NilError(t, err)

+

+	d := daemon.New(t)

+	d.StartWithBusybox(ctx, t, "--default-shm-size="+defaultSize)

+	defer d.Stop(t)

+

+	apiClient := d.NewClientT(t)

+

+	tests := []struct {

+		doc     string

+		opt     container.ConfigOpt

+		expSize string

+		expErr  string

+	}{

+		{

+			doc:     "nil hostConfig",

+			opt:     container.WithHostConfig(nil),

+			expSize: defaultSize,

+		},

+		{

+			doc:     "empty hostConfig",

+			opt:     container.WithHostConfig(&containertypes.HostConfig{}),

+			expSize: defaultSize,

+		},

+		{

+			doc:     "custom shmSize",

+			opt:     container.WithHostConfig(&containertypes.HostConfig{ShmSize: defaultSizeBytes * 2}),

+			expSize: "2000k",

+		},

+		{

+			doc:    "negative shmSize",

+			opt:    container.WithHostConfig(&containertypes.HostConfig{ShmSize: -1}),

+			expErr: "Error response from daemon: SHM size can not be less than 0",

+		},

+	}

+

+	for _, tc := range tests {

+		t.Run(tc.doc, func(t *testing.T) {

+			if tc.expErr != "" {

+				cfg := container.NewTestConfig(container.WithCmd("sh", "-c", "grep /dev/shm /proc/self/mountinfo"), tc.opt)

+				_, err := container.CreateFromConfig(ctx, apiClient, cfg)

+				assert.Check(t, is.ErrorContains(err, tc.expErr))

+				assert.Check(t, is.ErrorType(err, cerrdefs.IsInvalidArgument))

+				return

+			}

+

+			cID := container.Run(ctx, t, apiClient,

+				container.WithCmd("sh", "-c", "grep /dev/shm /proc/self/mountinfo"),

+				tc.opt,

+			)

+

+			t.Cleanup(func() {

+				container.Remove(ctx, t, apiClient, cID, containertypes.RemoveOptions{})

+			})

+

+			expectedSize, err := units.RAMInBytes(tc.expSize)

+			assert.NilError(t, err)

+

+			ctr := container.Inspect(ctx, t, apiClient, cID)

+			assert.Check(t, is.Equal(ctr.HostConfig.ShmSize, expectedSize))

+

+			out, err := container.Output(ctx, apiClient, cID)

+			assert.NilError(t, err)

+

+			// e.g., "218 213 0:87 / /dev/shm rw,nosuid,nodev,noexec,relatime - tmpfs shm rw,size=1000k"

+			assert.Assert(t, is.Contains(out.Stdout, "/dev/shm "), "shm mount not found in output: \n%v", out.Stdout)

+			assert.Check(t, is.Contains(out.Stdout, "size="+tc.expSize))

+		})

+	}

+}

@@ -12,6 +12,9 @@ import (

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

 )

+// ConfigOpt is an option to apply to a container.

+type ConfigOpt func(*TestContainerConfig)

+

 // WithName sets the name of the container

 func WithName(name string) func(*TestContainerConfig) {

 	return func(c *TestContainerConfig) {

@@ -361,3 +364,10 @@ func WithContainerWideMacAddress(address string) func(c *TestContainerConfig) {

 		c.Config.MacAddress = address //nolint:staticcheck // ignore SA1019: field is deprecated, but still used on API < v1.44.

 	}

 }

+

+// WithHostConfig sets a custom [container.HostConfig] for the container.

+func WithHostConfig(hc *container.HostConfig) func(c *TestContainerConfig) {

+	return func(c *TestContainerConfig) {

+		c.HostConfig = hc

+	}

+}