AndrewGuenther/fck-nat — reverse-engineered prompt

Build me a small AWS project that creates a cheap NAT instance AMI as an alternative to AWS Managed NAT Gateway. I want it to run on Amazon Linux 2023, support both ARM and x86 EC2 instances, and be easy to launch on tiny instance types like t4g.nano to save money.

It should configure the machine so private subnets can get outbound internet access through it, with sensible firewall, routing, and startup service settings that survive reboots. Include a way to reuse an existing bastion host as the NAT box if possible, and include a simple high availability option so another instance can take over if one fails.

Please include clear setup docs with the cost comparison, when not to use this and when Managed NAT Gateway is safer, plus basic build and release commands for producing the AMIs. Keep it maintainable and security patch friendly. Look up current AWS docs online if needed.