libct: criuSwrk: only iterate over CriuOpts if debug is set

In case log level is less than debug, this code does nothing,
so let's add a condition and skip it entirely.

Add a test case to make sure this code path is hit.

Signed-off-by: Kir Kolyshkin <[email protected]>

libcontainer/container_linux.go

@@ -1523,8 +1523,9 @@ func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *
 	// should be empty. For older CRIU versions it still will be
 	// available but empty. criurpc.CriuReqType_VERSION actually
 	// has no req.GetOpts().
-	if !(req.GetType() == criurpc.CriuReqType_FEATURE_CHECK ||
-		req.GetType() == criurpc.CriuReqType_VERSION) {
+	if logrus.GetLevel() >= logrus.DebugLevel &&
+		!(req.GetType() == criurpc.CriuReqType_FEATURE_CHECK ||
+			req.GetType() == criurpc.CriuReqType_VERSION) {
 
 		val := reflect.ValueOf(req.GetOpts())
 		v := reflect.Indirect(val)

tests/integration/checkpoint.bats

@@ -99,15 +99,15 @@ function simple_cr() {
 
 	for _ in $(seq 2); do
 		# checkpoint the running container
-		runc --criu "$CRIU" checkpoint --work-path ./work-dir test_busybox
+		runc --criu "$CRIU" "$@" checkpoint --work-path ./work-dir test_busybox
 		grep -B 5 Error ./work-dir/dump.log || true
 		[ "$status" -eq 0 ]
 
 		# after checkpoint busybox is no longer running
 		testcontainer test_busybox checkpointed
 
 		# restore from checkpoint
-		runc --criu "$CRIU" restore -d --work-path ./work-dir --console-socket "$CONSOLE_SOCKET" test_busybox
+		runc --criu "$CRIU" "$@" restore -d --work-path ./work-dir --console-socket "$CONSOLE_SOCKET" test_busybox
 		grep -B 5 Error ./work-dir/restore.log || true
 		[ "$status" -eq 0 ]
 
@@ -120,6 +120,10 @@ function simple_cr() {
 	simple_cr
 }
 
+@test "checkpoint and restore (with --debug)" {
+	simple_cr --debug
+}
+
 @test "checkpoint and restore (cgroupns)" {
 	# cgroupv2 already enables cgroupns so this case was tested above already
 	requires cgroups_v1 cgroupns