variables.tf

variable "enabled" {
  description = "Enable or not costly resources"
  type        = bool
  default     = true
}

variable "dry_run" {
  description = "Use this flag for safely standing up resources without applying any route changes. Useful for transitioning existing environments from NAT Gateway."
  type        = bool
  default     = false
}

variable "name" {
  description = "Name for all the resources as identifier"
  type        = string
}

variable "vpc_id" {
  description = "ID of the VPC"
  type        = string
}

variable "public_subnet" {
  description = "ID of the public subnet to place the NAT instance"
  type        = string
}

variable "private_subnets_cidr_blocks" {
  description = "List of CIDR blocks of the private subnets. The NAT instance accepts connections from this subnets"
  type        = list(any)
}

variable "private_route_table_ids" {
  description = "List of ID of the route tables for the private subnets. You can set this to assign the each default route to the NAT instance"
  type        = list(any)
  default     = []
}

variable "routes" {
  description = "List of CIDRs to break each private subnet into. Caution: this must not exceed the ENI capacity of the provisioned EC2 instance types."
  type        = list(string)
  default     = ["0.0.0.0/1", "128.0.0.0/1"]
}

variable "image_id" {
  description = "AMI of the NAT instance. Default to the latest Amazon Linux 2"
  type        = string
  default     = ""
}

variable "instance_types" {
  description = "Candidates of spot instance type for the NAT instance. This is used in the mixed instances policy"
  type        = list(any)
  default     = ["t3.medium", "t3a.medium"]
}

variable "use_spot_instance" {
  description = "Whether to use spot or on-demand EC2 instance"
  type        = bool
  default     = true
}

variable "key_name" {
  description = "Name of the key pair for the NAT instance. You can set this to assign the key pair to the NAT instance"
  type        = string
  default     = ""
}

variable "tags" {
  description = "Tags applied to resources created with this module"
  type        = map(any)
  default     = {}
}

variable "user_data_write_files" {
  description = "Additional write_files section of cloud-init"
  type        = list(any)
  default     = []
}

variable "user_data_runcmd" {
  description = "Additional runcmd section of cloud-init"
  type        = list(any)
  default     = []
}

locals {
  // Merge the default tags and user-specified tags.
  // User-specified tags take precedence over the default.
  common_tags = merge(
    {
      Name = "nat-instance-${var.name}"
    },
    var.tags,
  )
}