@@ -2426,28 +2426,6 @@ func (s *DockerSuite) TestContainerNetworkMode(c *testing.T) {

 	}

 }

-func (s *DockerSuite) TestRunModePIDHost(c *testing.T) {

-	// Not applicable on Windows as uses Unix-specific capabilities

-	testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux, NotUserNamespace)

-

-	hostPid, err := os.Readlink("/proc/1/ns/pid")

-	if err != nil {

-		c.Fatal(err)

-	}

-

-	out, _ := dockerCmd(c, "run", "--pid=host", "busybox", "readlink", "/proc/self/ns/pid")

-	out = strings.Trim(out, "\n")

-	if hostPid != out {

-		c.Fatalf("PID different with --pid=host %s != %s\n", hostPid, out)

-	}

-

-	out, _ = dockerCmd(c, "run", "busybox", "readlink", "/proc/self/ns/pid")

-	out = strings.Trim(out, "\n")

-	if hostPid == out {

-		c.Fatalf("PID should be different without --pid=host %s == %s\n", hostPid, out)

-	}

-}

-

 func (s *DockerSuite) TestRunModeUTSHost(c *testing.T) {

 	// Not applicable on Windows as uses Unix-specific capabilities

 	testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux)

new file mode 100644

@@ -0,0 +1,38 @@

+package container // import "github.com/docker/docker/integration/container"

+

+import (

+	"context"

+	"os"

+	"testing"

+	"time"

+

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

+	"gotest.tools/v3/assert"

+	"gotest.tools/v3/poll"

+	"gotest.tools/v3/skip"

+)

+

+func TestPidHost(t *testing.T) {

+	skip.If(t, testEnv.DaemonInfo.OSType != "linux")

+	skip.If(t, testEnv.IsRemoteDaemon())

+	skip.If(t, testEnv.IsRootless, "https://github.com/moby/moby/issues/41457")

+

+	hostPid, err := os.Readlink("/proc/1/ns/pid")

+	assert.NilError(t, err)

+

+	defer setupTest(t)()

+	client := testEnv.APIClient()

+	ctx := context.Background()

+

+	cID := container.Run(ctx, t, client, func(c *container.TestContainerConfig) {

+		c.HostConfig.PidMode = "host"

+	})

+	poll.WaitOn(t, container.IsInState(ctx, client, cID, "running"), poll.WithDelay(100*time.Millisecond))

+	cPid := container.GetContainerNS(ctx, t, client, cID, "pid")

+	assert.Assert(t, hostPid == cPid)

+

+	cID = container.Run(ctx, t, client)

+	poll.WaitOn(t, container.IsInState(ctx, client, cID, "running"), poll.WithDelay(100*time.Millisecond))

+	cPid = container.GetContainerNS(ctx, t, client, cID, "pid")

+	assert.Assert(t, hostPid != cPid)

+}

@@ -2,7 +2,6 @@ package container // import "github.com/docker/docker/integration/container"

 import (

 	"context"

-	"strings"

 	"testing"

 	"time"

@@ -11,20 +10,10 @@ import (

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

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

 	"gotest.tools/v3/assert"

-	is "gotest.tools/v3/assert/cmp"

 	"gotest.tools/v3/poll"

 	"gotest.tools/v3/skip"

 )

-// Gets the value of the cgroup namespace for pid 1 of a container

-func containerCgroupNamespace(ctx context.Context, t *testing.T, client *client.Client, cID string) string {

-	res, err := container.Exec(ctx, client, cID, []string{"readlink", "/proc/1/ns/cgroup"})

-	assert.NilError(t, err)

-	assert.Assert(t, is.Len(res.Stderr(), 0))

-	assert.Equal(t, 0, res.ExitCode)

-	return strings.TrimSpace(res.Stdout())

-}

-

 // Bring up a daemon with the specified default cgroup namespace mode, and then create a container with the container options

 func testRunWithCgroupNs(t *testing.T, daemonNsMode string, containerOpts ...func(*container.TestContainerConfig)) (string, string) {

 	d := daemon.New(t, daemon.WithDefaultCgroupNamespaceMode(daemonNsMode))

@@ -38,7 +27,7 @@ func testRunWithCgroupNs(t *testing.T, daemonNsMode string, containerOpts ...fun

 	poll.WaitOn(t, container.IsInState(ctx, client, cID, "running"), poll.WithDelay(100*time.Millisecond))

 	daemonCgroup := d.CgroupNamespace(t)

-	containerCgroup := containerCgroupNamespace(ctx, t, client, cID)

+	containerCgroup := container.GetContainerNS(ctx, t, client, cID, "cgroup")

 	return containerCgroup, daemonCgroup

 }

@@ -147,7 +136,7 @@ func TestCgroupNamespacesRunOlderClient(t *testing.T) {

 	poll.WaitOn(t, container.IsInState(ctx, client, cID, "running"), poll.WithDelay(100*time.Millisecond))

 	daemonCgroup := d.CgroupNamespace(t)

-	containerCgroup := containerCgroupNamespace(ctx, t, client, cID)

+	containerCgroup := container.GetContainerNS(ctx, t, client, cID, "cgroup")

 	if testEnv.DaemonInfo.CgroupVersion != "2" {

 		assert.Assert(t, daemonCgroup == containerCgroup)

 	} else {

new file mode 100644

@@ -0,0 +1,21 @@

+package container

+

+import (

+	"context"

+	"strings"

+	"testing"

+

+	"github.com/docker/docker/client"

+	"gotest.tools/v3/assert"

+	is "gotest.tools/v3/assert/cmp"

+)

+

+// GetContainerNS gets the value of the specified namespace of a container

+func GetContainerNS(ctx context.Context, t *testing.T, client client.APIClient, cID, nsName string) string {

+	t.Helper()

+	res, err := Exec(ctx, client, cID, []string{"readlink", "/proc/self/ns/" + nsName})

+	assert.NilError(t, err)

+	assert.Assert(t, is.Len(res.Stderr(), 0))

+	assert.Equal(t, 0, res.ExitCode)

+	return strings.TrimSpace(res.Stdout())

+}