locals {
  base_cidr_mask_size = tonumber(split("/", var.base_cidr)[1])

  # Determine if custom subnet details are provided
  use_custom_details = length(var.subnets) > 0

  # Use provided subnet details or generate subnet names and use default netnum and mask size
  final_subnet_details = local.use_custom_details ? var.subnets : {
    for i, size in var.subnet_sizes : format("subnet%s", i + 1) => {
      mask_size = size
      netnum    = i # Default netnum, can be changed to another logic
    }
  }

  calculated_subnets = {
    for subnet_name, details in local.final_subnet_details :
    subnet_name => cidrsubnet(var.base_cidr, details.mask_size - local.base_cidr_mask_size, details.netnum)
  }

  subnet_names = sort(keys(local.calculated_subnets))
}

Requirements

No requirements.

Providers

No providers.

Modules

No modules.

Resources

No resources.

Inputs

Name	Description	Type	Default	Required
base_cidr	The base CIDR block	string	n/a	yes
subnet_sizes	List of subnet sizes if names are to be generated	list(number)	[]	no
subnets	Map of subnet names to their desired mask sizes and netnum	map(object({ mask_size = number netnum = number }))	{}	no

Outputs

Name	Description
base_cidr	The base CIDR given to the module for calculation
subnet_first_ip	A map of subnet names to their first usable IP addresses.
subnet_first_last_ip	A map of subnet names to their last usable IP addresses.
subnet_last_ip	A map of subnet names to their first and last usable IP addresses.
subnet_mask_sizes	A map of subnet names to their mask sizes.
subnet_names	A sorted list of subnet names calculated based on the provided details or sizes.
subnet_ranges	A list of subnet CIDR ranges corresponding to the sorted subnet names, ensuring consistent ordering.
subnet_sizes	A map of subnet names to the count of usable IPs in each subnet.
subnets_map	A map of subnet names to their corresponding generated subnet CIDR ranges.