Skip Docker restore tests on Docker v28+.

Docker's `restore` functionality is broken starting from v28 due to
moby/moby#50750. This change adds a version check to
`dockerutil` and skips tests that rely on `docker restore` if the Docker
version is v28 or greater. TCP checkpoint/restore tests are also refactored to
centralize common setup and version checks.

PiperOrigin-RevId: 818827864

Author: ayushr2

pkg/test/dockerutil/dockerutil.go

@@ -89,10 +89,7 @@ func PrintDockerConfig() {
 	log.Printf("Docker config (from %v):\n--------\n%v\n--------\n", *config, string(configBytes))
 }
 
-// EnsureSupportedDockerVersion checks if correct docker is installed.
-//
-// This logs directly to stderr, as it is typically called from a Main wrapper.
-func EnsureSupportedDockerVersion() {
+func getDockerVersion() (int, int) {
 	cmd := exec.Command(dockerCLIPath(), "version")
 	out, err := cmd.CombinedOutput()
 	if err != nil {
@@ -105,6 +102,14 @@ func EnsureSupportedDockerVersion() {
 	}
 	major, _ := strconv.Atoi(matches[1])
 	minor, _ := strconv.Atoi(matches[2])
+	return major, minor
+}
+
+// EnsureSupportedDockerVersion checks if correct docker is installed.
+//
+// This logs directly to stderr, as it is typically called from a Main wrapper.
+func EnsureSupportedDockerVersion() {
+	major, minor := getDockerVersion()
 	if major < 17 || (major == 17 && minor < 9) {
 		log.Fatalf("Docker version 17.09.0 or greater is required, found: %02d.%02d", major, minor)
 	}
@@ -123,6 +128,14 @@ func EnsureDockerExperimentalEnabled() {
 	}
 }
 
+// IsRestoreSupported returns true if the docker version supports restore.
+// Docker restore broke starting v28 due to
+// https://github.com/moby/moby/issues/50750.
+func IsRestoreSupported() bool {
+	major, _ := getDockerVersion()
+	return major <= 27
+}
+
 // RuntimePath returns the binary path for the current runtime.
 func RuntimePath() (string, error) {
 	rs, err := runtimeMap()

test/e2e/integration_runtime_test.go

@@ -249,6 +249,9 @@ func TestOverlayCheckpointRestore(t *testing.T) {
 		t.Skip("Checkpoint is not supported.")
 	}
 	dockerutil.EnsureDockerExperimentalEnabled()
+	if !dockerutil.IsRestoreSupported() {
+		t.Skip("Restore is not supported.")
+	}
 
 	dir, err := os.MkdirTemp(testutil.TmpDir(), "submount")
 	if err != nil {

test/e2e/integration_test.go

@@ -179,6 +179,9 @@ func TestCheckpointRestore(t *testing.T) {
 		t.Skip("Checkpoint is not supported.")
 	}
 	dockerutil.EnsureDockerExperimentalEnabled()
+	if !dockerutil.IsRestoreSupported() {
+		t.Skip("Restore is not supported.")
+	}
 
 	ctx := context.Background()
 	d := dockerutil.MakeContainer(ctx, t)
@@ -1268,7 +1271,25 @@ func connectAndReadWrite(t *testing.T, serverIP string, port int) {
 	}
 }
 
-func testCheckpointRestoreTCPConnection(ctx context.Context, t *testing.T, d *dockerutil.Container, fName string, numConn int, restoreLoopback bool) {
+func testCheckpointRestoreTCPConnection(t *testing.T, netstackSR bool, fName string, numConn int, restoreLoopback bool) {
+	if !testutil.IsCheckpointSupported() {
+		t.Skip("Checkpoint is not supported.")
+	}
+	dockerutil.EnsureDockerExperimentalEnabled()
+	if !dockerutil.IsRestoreSupported() {
+		t.Skip("Restore is not supported.")
+	}
+
+	var d *dockerutil.Container
+	ctx := context.Background()
+	if netstackSR {
+		if !testutil.IsRunningWithSaveRestoreNetstack() {
+			t.Skip("Netstack save restore is not supported.")
+		}
+		d = dockerutil.MakeContainerWithRuntime(ctx, t, "-save-restore-netstack")
+	} else {
+		d = dockerutil.MakeContainer(ctx, t)
+	}
 	defer d.CleanUp(ctx)
 
 	opts := dockerutil.RunOpts{
@@ -1322,59 +1343,22 @@ func testCheckpointRestoreTCPConnection(ctx context.Context, t *testing.T, d *do
 
 // Test to check restore of a TCP listening connection without netstack S/R.
 func TestRestoreListenConn(t *testing.T) {
-	if !testutil.IsCheckpointSupported() {
-		t.Skip("Checkpoint is not supported.")
-	}
-	dockerutil.EnsureDockerExperimentalEnabled()
-
-	ctx := context.Background()
-	d := dockerutil.MakeContainer(ctx, t)
-	testCheckpointRestoreTCPConnection(ctx, t, d, "./tcp_server" /* fName */, 1 /* numConn */, false /* restoreLoopback */)
+	testCheckpointRestoreTCPConnection(t, false /* netstackSR */, "./tcp_server" /* fName */, 1 /* numConn */, false /* restoreLoopback */)
 }
 
 // Test to check restore of a TCP listening connection with netstack S/R.
 func TestRestoreListenConnWithNetstackSR(t *testing.T) {
-	if !testutil.IsCheckpointSupported() {
-		t.Skip("Checkpoint is not supported.")
-	}
-	if !testutil.IsRunningWithSaveRestoreNetstack() {
-		t.Skip("Netstack save restore is not supported.")
-	}
-	dockerutil.EnsureDockerExperimentalEnabled()
-
-	ctx := context.Background()
-	d := dockerutil.MakeContainerWithRuntime(ctx, t, "-save-restore-netstack")
-	testCheckpointRestoreTCPConnection(ctx, t, d, "./tcp_server" /* fName */, 1 /* numConn */, false /* restoreLoopback */)
+	testCheckpointRestoreTCPConnection(t, true /* netstackSR */, "./tcp_server" /* fName */, 1 /* numConn */, false /* restoreLoopback */)
 }
 
 // Test to check restore of multiple TCP listening connections with netstack S/R.
 func TestRestoreMultipleListenConnWithNetstackSR(t *testing.T) {
-	if !testutil.IsCheckpointSupported() {
-		t.Skip("Checkpoint is not supported.")
-	}
-	if !testutil.IsRunningWithSaveRestoreNetstack() {
-		t.Skip("Netstack save restore is not supported.")
-	}
-	dockerutil.EnsureDockerExperimentalEnabled()
-
-	ctx := context.Background()
-	d := dockerutil.MakeContainerWithRuntime(ctx, t, "-save-restore-netstack")
-	testCheckpointRestoreTCPConnection(ctx, t, d, "./tcp_stress_server" /* fName */, 100 /* numConn */, false /* restoreLoopback */)
+	testCheckpointRestoreTCPConnection(t, true /* netstackSR */, "./tcp_stress_server" /* fName */, 100 /* numConn */, false /* restoreLoopback */)
 }
 
 // Test to check restore of TCP established loopback connection with netstack S/R.
 func TestRestoreLoopbackConnWithNetstackSR(t *testing.T) {
-	if !testutil.IsCheckpointSupported() {
-		t.Skip("Checkpoint is not supported.")
-	}
-	if !testutil.IsRunningWithSaveRestoreNetstack() {
-		t.Skip("Netstack save restore is not supported.")
-	}
-	dockerutil.EnsureDockerExperimentalEnabled()
-
-	ctx := context.Background()
-	d := dockerutil.MakeContainerWithRuntime(ctx, t, "-save-restore-netstack")
-	testCheckpointRestoreTCPConnection(ctx, t, d, "./tcp_loopback" /* fName */, 1 /* numConn */, true /* restoreLoopback */)
+	testCheckpointRestoreTCPConnection(t, true /* netstackSR */, "./tcp_loopback" /* fName */, 1 /* numConn */, true /* restoreLoopback */)
 }
 
 // Test to check if sudo works

test/gpu/sr_test.go

@@ -30,6 +30,9 @@ func TestGPUCheckpointRestore(t *testing.T) {
 		t.Skip("Checkpoint is not supported.")
 	}
 	dockerutil.EnsureDockerExperimentalEnabled()
+	if !dockerutil.IsRestoreSupported() {
+		t.Skip("Restore is not supported.")
+	}
 
 	ctx := context.Background()
 	c := dockerutil.MakeContainer(ctx, t)