Added option to keep containers running after checkpointing

CRIU supports to leave processes running after checkpointing:

  -R|--leave-running    leave tasks in running state after checkpoint

runc also support to leave containers running after checkpointing:

   --leave-running      leave the process running after checkpointing

With this commit the support to leave a container running after
checkpointing is brought to Podman:

   --leave-running, -R  leave the container running after writing checkpoint to disk

Now it is possible to checkpoint a container at some point in time
without stopping the container. This can be used to rollback the
container to an early state:

$ podman run --tmpfs /tmp --name podman-criu-test -d docker://docker.io/yovfiatbeb/podman-criu-test
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
3
$ podman container checkpoint -R -l
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
4
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
5
$ podman stop -l
$ podman container restore -l
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
4

So after checkpointing the container kept running and was stopped after
some time. Restoring this container will restore the state right at the
checkpoint.

Signed-off-by: Adrian Reber <areber@redhat.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index 003e8284a..e6071945d 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -440,7 +440,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 	if c.state.State != ContainerStateRunning {
 		return errors.Wrapf(ErrCtrStateInvalid, "%q is not running, cannot checkpoint", c.state.State)
 	}
-	if err := c.runtime.ociRuntime.checkpointContainer(c); err != nil {
+	if err := c.runtime.ociRuntime.checkpointContainer(c, options); err != nil {
 		return err
 	}
 
@@ -457,11 +457,13 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 
 	logrus.Debugf("Checkpointed container %s", c.ID())
 
-	c.state.State = ContainerStateStopped
+	if !options.KeepRunning {
+		c.state.State = ContainerStateStopped
 
-	// Cleanup Storage and Network
-	if err := c.cleanup(ctx); err != nil {
-		return err
+		// Cleanup Storage and Network
+		if err := c.cleanup(ctx); err != nil {
+			return err
+		}
 	}
 
 	if !options.Keep {