this produces errors itself, e.g.:
```
for container in $failed_containers
+ docker inspect prometheus_openstack_exporter
[]
permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.45/containers/prometheus_openstack_exporter/json": dial unix /var/run/docker.sock: connect: permission denied
```
Signed-off-by: Sven Kieske <kieske@osism.tech>
Change-Id: I280e2660d187d966098ae39df6392503b1aa5bdf
c508479f44