I have a recent example of rolling out IPv6 in AWS:
1. Create a new VPC, get an auto-assigned /56 prefix from AWS.
2. Create subnets within the VPC. Each subnet needs an explicitly-specified /64 prefix. (Maybe it can be auto-assigned by AWS, but you may still want to follow a specific pattern for your subnets).
3. Add those subnet prefixis to security / Firewall rules.
You can do this with a sufficiently-advanced config language - perhaps it has a built-in function to generate subnets from a given prefix. But in my experience, using a general-purpose programming language makes it really easy to do this kind of automation. For reference, I did this using Pulumi with TypeScript, which works really well for this.
1. Create a new VPC, get an auto-assigned /56 prefix from AWS.
2. Create subnets within the VPC. Each subnet needs an explicitly-specified /64 prefix. (Maybe it can be auto-assigned by AWS, but you may still want to follow a specific pattern for your subnets).
3. Add those subnet prefixis to security / Firewall rules.
You can do this with a sufficiently-advanced config language - perhaps it has a built-in function to generate subnets from a given prefix. But in my experience, using a general-purpose programming language makes it really easy to do this kind of automation. For reference, I did this using Pulumi with TypeScript, which works really well for this.