Remove stale dockershim containers

remove-stale-containers.py

#!/usr/bin/env python

## If you see messages like this on your kubelet journal:
##
## Mar 25 22:36:44 ip-10-0-3-67.ec2.internal dockerd-current[28612]: time="2018-03-25T22:36:44.419126265Z" level=error msg="Handler for GET /v1.24/containers/60532fa8184bdf41e52788194faa1253f1168e3ad4f54f7c159192fe66c4bb1d/json returned error: No such container: 60532fa8184bdf41e52788194faa1253f1168e3ad4f54f7c159192fe66c4bb1d"
##
## use this script to remove dockershim container files from /var/lib/dockershim/sandbox

import os, glob, subprocess

containers = subprocess.check_output(["docker", "ps", "--no-trunc", "-qa"]).split()

for p in glob.glob('/var/lib/dockershim/sandbox/*'):
    c = p.split('/')[-1]
    if c not in containers:
        print 'Removing stale container', c
        os.unlink(p)