Automatic merge from submit-queue
dockershim: Fix the race condition in ListPodSandbox
In ListPodSandbox(), we
1. List all sandbox docker containers
2. List all sandbox checkpoints. If the checkpoint does not have a
corresponding container in (1), we return partial result based on
the checkpoint.
The problem is that new PodSandboxes can be created between step (1) and
(2). In those cases, we will see the checkpoints, but not the sandbox
containers. This leads to strange behavior because the partial result
from the checkpoint does not include some critical information. For
example, the creation timestamp'd be zero, and that would cause kubelet's
garbage collector to immediately remove the sandbox.
This change fixes that by getting the list of checkpoints before listing
all the containers (since in RunPodSandbox we create them in the reverse
order).
6fac75c80a