add pre checkpoint

Signed-off-by: Zhuohan Chen <chen_zhuohan@163.com>

1 files changed, 39 insertions, 2 deletions

diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index ac20e1f25..705086bda 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -812,6 +812,9 @@ func (c *Container) exportCheckpoint(options ContainerCheckpointOptions) error {
 		"spec.dump",
 		"network.status"}
 
+	if options.PreCheckPoint {
+		includeFiles[0] = "pre-checkpoint"
+	}
 	// Get root file-system changes included in the checkpoint archive
 	rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar")
 	deleteFilesList := filepath.Join(c.bundlePath(), "deleted.files")
@@ -1015,6 +1018,15 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 
 	defer c.newContainerEvent(events.Checkpoint)
 
+	// There is a bug from criu: https://github.com/checkpoint-restore/criu/issues/116
+	// We have to change the symbolic link from absolute path to relative path
+	if options.WithPrevious {
+		os.Remove(path.Join(c.CheckpointPath(), "parent"))
+		if err := os.Symlink("../pre-checkpoint", path.Join(c.CheckpointPath(), "parent")); err != nil {
+			return err
+		}
+	}
+
 	if options.TargetFile != "" {
 		if err = c.exportCheckpoint(options); err != nil {
 			return err
@@ -1023,7 +1035,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 
 	logrus.Debugf("Checkpointed container %s", c.ID())
 
-	if !options.KeepRunning {
+	if !options.KeepRunning && !options.PreCheckPoint {
 		c.state.State = define.ContainerStateStopped
 
 		// Cleanup Storage and Network
@@ -1032,7 +1044,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 		}
 	}
 
-	if !options.Keep {
+	if !options.Keep && !options.PreCheckPoint {
 		cleanup := []string{
 			"dump.log",
 			"stats-dump",
@@ -1080,6 +1092,21 @@ func (c *Container) importCheckpoint(input string) error {
 	return nil
 }
 
+func (c *Container) importPreCheckpoint(input string) error {
+	archiveFile, err := os.Open(input)
+	if err != nil {
+		return errors.Wrap(err, "failed to open pre-checkpoint archive for import")
+	}
+
+	defer archiveFile.Close()
+
+	err = archive.Untar(archiveFile, c.bundlePath(), nil)
+	if err != nil {
+		return errors.Wrapf(err, "Unpacking of pre-checkpoint archive %s failed", input)
+	}
+	return nil
+}
+
 func (c *Container) restore(ctx context.Context, options ContainerCheckpointOptions) (retErr error) {
 	if err := c.checkpointRestoreSupported(); err != nil {
 		return err
@@ -1089,6 +1116,12 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 		return errors.Wrapf(define.ErrCtrStateInvalid, "container %s is running or paused, cannot restore", c.ID())
 	}
 
+	if options.ImportPrevious != "" {
+		if err := c.importPreCheckpoint(options.ImportPrevious); err != nil {
+			return err
+		}
+	}
+
 	if options.TargetFile != "" {
 		if err := c.importCheckpoint(options.TargetFile); err != nil {
 			return err
@@ -1322,6 +1355,10 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 		if err != nil {
 			logrus.Debugf("Non-fatal: removal of checkpoint directory (%s) failed: %v", c.CheckpointPath(), err)
 		}
+		err = os.RemoveAll(c.PreCheckPointPath())
+		if err != nil {
+			logrus.Debugf("Non-fatal: removal of pre-checkpoint directory (%s) failed: %v", c.PreCheckPointPath(), err)
+		}
 		cleanup := [...]string{"restore.log", "dump.log", "stats-dump", "stats-restore", "network.status", "rootfs-diff.tar", "deleted.files"}
 		for _, del := range cleanup {
 			file := filepath.Join(c.bundlePath(), del)