1. Proposed title of this feature request

Add ability to scheduler to track available IP addresses in nodes

2. What is the nature and description of the request?

The kube-scheduler currently does not have any plugin checking how many IP
addresses are left on a node for allocating. The node object does not
report this information either

The scheduler can schedule a Pod to run on a node even after the node has exhausted all of its IPv4 addresses

Use Extended resources on nodes to report information about available IP addresses. The scheduler should check this information when assigning pods.

Solutions for this have been discussed here:

https://github.com/kubernetes/enhancements/issues/611

https://github.com/aws/amazon-vpc-cni-k8s/issues/26

3. Why does the customer need this? (List the business requirements here)

A customer configured a small range of IPs addresses for their nodes, and while this was valid configuration, their cluster ran into an error as reported here:

https://issues.redhat.com/browse/OHSS-7178

4. List any affected packages or components.

Scheduler, nodes, pods