Issue

The following issue can be observed when running openstack overcloud container image prepare as user stack:

(undercloud) [stack@undercloud-1 ~]$   openstack overcloud container image prepare \
>     --namespace=registry.access.redhat.com/rhosp13 \
>     --prefix=openstack- \
>     -e /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-ansible.yaml \
>     --set ceph_namespace=registry.access.redhat.com/rhceph \
>     --set ceph_image=rhceph-3-rhel7 \
>     --tag-from-label {version}-{release} \
>     --output-env-file=/home/stack/templates/overcloud_images.yaml

Error inspecting image: docker://registry.access.redhat.com/rhosp13/openstack-gnocchi-metricd:latest
time="2018-10-26T17:52:45-04:00" level=fatal msg="error getting username and password: error reading JSON file "/run/user/0/containers/auth.json": error unmarshaling JSON at "/run/user/0/containers/auth.json": unexpected end of JSON input" 

Any of the containers can be affected randomly, some containers may actually work for inspection.

When using skopeo, the same issue can we reproduced:

[root@undercloud-1 ~]# su stack
[stack@undercloud-1 root]$  skopeo inspect docker://registry.access.redhat.com/rhosp13/openstack-glance-api:latest
FATA[0000] error getting username and password: error reading JSON file "/run/user/0/containers/auth.json": error unmarshaling JSON at "/run/user/0/containers/auth.json": unexpected end of JSON input