Prometheus installation fails in Openshift 3.9 with ImagePullBackOff

Issue

The Installing Prometheus playbook fails with the following error.

FAILED - RETRYING: Verify that node exporter is running (2 retries left).
FAILED - RETRYING: Verify that node exporter is running (1 retries left).
fatal: [master1.example.com]: FAILED! => {"attempts": 120, "changed": false, "content": "", "failed": true, "msg": "Status code was not [200]: Request failed: <urlopen error [Errno 111] Connection refused>", "redirected": false, "status": -1, "url": "http://localhost:9100/metrics"}
    to retry, use: --limit @/usr/share/ansible/openshift-ansible/playbooks/openshift-prometheus/config.retry

PLAY RECAP ******************************************************************************************************************************
master1.example.com        : ok=80   changed=15   unreachable=0    failed=1   
localhost                  : ok=11   changed=0    unreachable=0    failed=0   


INSTALLER STATUS ************************************************************************************************************************
Initialization             : Complete (0:00:38)
Prometheus Install         : In Progress (0:04:11)
    This phase can be restarted by running: playbooks/openshift-prometheus/config.yml