[rnd] evaluate possibility, requirements and limitations for implementing IPAM for AWS

[BROngineer]

Summary

Developed a prototype that creates a network interface for each worker node in a cluster using a specified IP address. This prototype uses a patched version of cluster-api-provider-aws to fix a known bug.

• Issue: #5594
• PR: #5595
• Prototype [https://github.com/kylewuolle/hmc/tree/ipam-aws]

Known Issues

1. The prototype does not handle cases where the specified IP address is already in use.
2. It lacks error handling for network interface creation, potentially causing repeated attempts to create the same interface.
3. It does not create network interfaces for control plane nodes.

Code Changes Needed

1. IP Conflict Handling:
   Check the return code from the network interface creation call. If it indicates an IP conflict, update the ClusterIPAMClaim status accordingly.

2. Tagging for Detection:
   Add tags to created network interfaces. These can be used in subsequent operations to detect existing interfaces either before creation or after a failure due to conflict.

3. Control Plane Support:
   Update the control plane node template to include network interface creation logic, similar to the worker node template.