Scaleup playbook fails with hostsubnets not found error when trying to add a new node to the cluster

Issue

• Scaleup playbook fails with hostsubnets not found error when trying to add a new node to the cluster
• We are tying to add nodes to OSE cluster, it fails to start atomic-openshift-node service on the nodes.
• journalctl reports below logs onnodewhen trying to add a new node to thecluster`:

Aug 21 06:49:12 node1 atomic-openshift-node: W0821 06:49:12.346841   27553 subnets.go:112] Could not find an allocated subnet for node: node1.example.com, Waiting...
Aug 21 06:49:12 node1 atomic-openshift-node: F0821 06:49:12.847008   27553 node.go:310] error: SDN node startup failed: Failed to start plugin: Failed to get subnet for this host: node1.example.com, error: hostsubnets "node1.example.com" not found

• journalctl reports below logs on themasterwhen trying to add a new node to thecluster`:

668421 Aug 21 04:35:27 master atomic-openshift-master-controllers[106849]: E0821 04:35:27.452701  106849 subnets.go:147] Error adding node: Error allocating network for node node1.example.com: No subnets available.