Pods are failing to start on a node due to IP address exhaustion in OpenShift

Issue

• Pods are failing to create on a node. The following errors are present in the node log file:

  atomic-openshift-node[19006]: E0121 12:14:30.367335   19006 pod_workers.go:182] Error syncing pod ... failed: rpc error: code = 2 desc = NetworkPlugin cni failed to set up pod ... network: CNI request failed with status 400: 'failed to run IPAM for : failed to run CNI IPAM ADD: no IP addresses available in network: openshift-sdn\n'