[BUG] Node Slice Fast IPAM Object Too Large

[ivelichkovich]

Describe the bug A clear and concise description of what the bug is.

If you use a very large CIDR range with a very small node slice size i.e. /8 and /27 then there is so many possible slices that they are too large to fit within a kubernetes object with max 1.5MB object size.

Expected behavior A clear and concise description of what you expected to happen.

We should validate this or surface this error at the onset that it's not supported. A /8 and a /27 would support 524,288 which is way beyond official 5,000 node support. Whereabouts should support more than the base 5,000 but I don't think we need to support 500,000.

To Reproduce Steps to reproduce the behavior:

1. Use Node Slice Pool
2. Create NAD with ip_range of /8 and node_slice_size of /27

Environment:

• Whereabouts version : latest main, unreleased yet
• Kubernetes version (use kubectl version): any
• Network-attachment-definition: N/A
• Whereabouts configuration (on the host): N/A
• OS (e.g. from /etc/os-release): N/A
• Kernel (e.g. uname -a): N/A
• Others: N/A

Additional info / context Add any other information / context about the problem here.

My team can work on a resolution for this. Initially thinking we should just surface this as an error and document the supported limits.