libct/int: checkpoint test: skip pre-dump if not avail

Since we're now testing on ARM, the test case fails when trying to do
pre-dump since MemTrack is not available.

Skip the pre-dump part if so.

This also reverts part of commit 3f4a73d as it is no longer needed
(now, instead of skipping the whole test, we're just skipping the
pre-dump).

[Review with --ignore-all-space]

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libcontainer/integration/checkpoint_test.go

@@ -2,7 +2,6 @@ package integration
 
 import (
 	"bytes"
-	"errors"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -14,11 +13,11 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+func criuFeature(feature string) bool {
+	return exec.Command("criu", "check", "--feature", feature).Run() == nil
+}
+
 func TestUsernsCheckpoint(t *testing.T) {
-	cmd := exec.Command("criu", "check", "--feature", "userns")
-	if err := cmd.Run(); err != nil {
-		t.Skip("Test requires userns")
-	}
 	testCheckpoint(t, true)
 }
 
@@ -41,6 +40,10 @@ func testCheckpoint(t *testing.T, userns bool) {
 		t.Skip("Test requires criu >= 3.17-4 on CentOS Stream 9.")
 	}
 
+	if userns && !criuFeature("userns") {
+		t.Skip("Test requires userns")
+	}
+
 	config := newTemplateConfig(t, &tParam{userns: userns})
 	stateDir := t.TempDir()
 
@@ -74,41 +77,43 @@ func testCheckpoint(t *testing.T, userns bool) {
 	ok(t, err)
 
 	tmp := t.TempDir()
+	var parentImage string
+
+	// Test pre-dump if mem_dirty_track is available.
+	if criuFeature("mem_dirty_track") {
+		parentImage = "../criu-parent"
+		parentDir := filepath.Join(tmp, "criu-parent")
+		preDumpOpts := &libcontainer.CriuOpts{
+			ImagesDirectory: parentDir,
+			WorkDirectory:   parentDir,
+			PreDump:         true,
+		}
 
-	parentDir := filepath.Join(tmp, "criu-parent")
-	preDumpOpts := &libcontainer.CriuOpts{
-		ImagesDirectory: parentDir,
-		WorkDirectory:   parentDir,
-		PreDump:         true,
-	}
-
-	if err := container.Checkpoint(preDumpOpts); err != nil {
-		if errors.Is(err, libcontainer.ErrCriuMissingFeatures) {
-			t.Skip(err)
+		if err := container.Checkpoint(preDumpOpts); err != nil {
+			t.Fatal(err)
 		}
-		t.Fatal(err)
-	}
 
-	state, err := container.Status()
-	ok(t, err)
+		state, err := container.Status()
+		ok(t, err)
 
-	if state != libcontainer.Running {
-		t.Fatal("Unexpected preDump state: ", state)
+		if state != libcontainer.Running {
+			t.Fatal("Unexpected preDump state: ", state)
+		}
 	}
 
 	imagesDir := filepath.Join(tmp, "criu")
 
 	checkpointOpts := &libcontainer.CriuOpts{
 		ImagesDirectory: imagesDir,
 		WorkDirectory:   imagesDir,
-		ParentImage:     "../criu-parent",
+		ParentImage:     parentImage,
 	}
 
 	if err := container.Checkpoint(checkpointOpts); err != nil {
 		t.Fatal(err)
 	}
 
-	state, err = container.Status()
+	state, err := container.Status()
 	ok(t, err)
 
 	if state != libcontainer.Stopped {