chore: ignore the nat gateway configuration when gateway is not enabled

Author: gambol99

locals.tf

@@ -1,28 +1,32 @@
 locals {
   # Th current region
   region = data.aws_region.current.name
+  # Indicates if the transit gateway is being proivisioned
+  enable_transit_gateway = var.transit_gateway_id != null
   # The id for the transit_gateway_id passed into the module
-  transit_gateway_id = var.enable_transit_gateway ? var.transit_gateway_id : null
-  # Is the routes to propagate down the transit gateway 
-  transit_routes = var.enable_transit_gateway && length(var.transit_gateway_routes) > 0 ? var.transit_gateway_routes : {}
+  transit_gateway_id = local.enable_transit_gateway ? var.transit_gateway_id : null
+  # Is the routes to propagate down the transit gateway
+  transit_routes = local.enable_transit_gateway && length(var.transit_gateway_routes) > 0 ? var.transit_gateway_routes : {}
+  # NAT Configuration mode
+  nat_gateway_mode = var.enable_nat_gateway ? var.nat_gateway_mode : "none"
   # The configuration for the private subnets
   private_subnet = var.private_subnet_netmask > 0 ? {
     private = {
-      connect_to_public_natgw = var.enable_nat_gateway ? true : false
+      connect_to_public_natgw = var.enable_nat_gateway
       netmask                 = var.private_subnet_netmask
       tags                    = merge(var.tags, var.private_subnet_tags)
     }
   } : null
   # Public subnets are optional
   public_subnet = var.public_subnet_netmask > 0 ? {
     public = {
-      nat_gateway_configuration = var.nat_gateway_mode
+      nat_gateway_configuration = local.nat_gateway_mode
       netmask                   = var.public_subnet_netmask
       tags                      = merge(var.tags, var.public_subnet_tags)
     }
   } : null
-  # Configuration for the transit subnets 
-  transit_subnet = var.enable_transit_gateway ? {
+  # Configuration for the transit subnets
+  transit_subnet = local.enable_transit_gateway ? {
     transit_gateway = {
       connect_to_public_natgw                         = var.enable_transit_gateway_subnet_natgw
       netmask                                         = 28
@@ -39,28 +43,28 @@ locals {
   private_subnet_cidrs = [for k, x in module.vpc.private_subnet_attributes_by_az : x.cidr_block if startswith(k, "private/")]
   # A map of private subnet id to cidr block
   private_subnet_cidr_by_id = { for k, x in module.vpc.private_subnet_attributes_by_az : x.id => x.cidr_block if startswith(k, "private/") }
-  # A map of az to private subnet id 
+  # A map of az to private subnet id
   private_subnet_id_by_az = { for k, x in module.vpc.private_subnet_attributes_by_az : trimprefix(k, "private/") => x.id if startswith(k, "private/") }
-  # A map of az to public subnet id 
+  # A map of az to public subnet id
   public_subnet_id_by_az = var.public_subnet_netmask > 0 ? { for k, x in module.vpc.public_subnet_attributes_by_az : k => x.id } : {}
-  # A map of public subnet id to cidr block 
+  # A map of public subnet id to cidr block
   public_subnet_cidr_by_id = var.public_subnet_netmask > 0 ? { for k, x in module.vpc.public_subnet_attributes_by_az : x.id => x.cidr_block } : {}
-  # public_subnet ranges 
+  # public_subnet ranges
   public_subnet_cidrs = var.public_subnet_netmask > 0 ? [for k, x in module.vpc.public_subnet_attributes_by_az : x.cidr_block] : []
   # The subnet id for the private subnets
   private_subnet_ids = [for k, x in module.vpc.private_subnet_attributes_by_az : x.id if startswith(k, "private/")]
   # The subnet id for the public subnets
   public_subnet_ids = var.public_subnet_netmask > 0 ? [for k, x in module.vpc.public_subnet_attributes_by_az : x.id] : []
   # The subnet id for the transit subnets
-  transit_subnet_ids = var.enable_transit_gateway ? [for k, x in module.vpc.tgw_subnet_attributes_by_az : x.id] : []
-  # A list of transit route table ids 
-  transit_route_table_ids = var.enable_transit_gateway ? [for k, x in module.vpc.rt_attributes_by_type_by_az.transit_gateway : x.id] : []
+  transit_subnet_ids = local.enable_transit_gateway ? [for k, x in module.vpc.tgw_subnet_attributes_by_az : x.id] : []
+  # A list of transit route table ids
+  transit_route_table_ids = local.enable_transit_gateway ? [for k, x in module.vpc.rt_attributes_by_type_by_az.transit_gateway : x.id] : []
   # The routing tables for the private subnets
   private_route_table_ids = [for k, x in module.vpc.rt_attributes_by_type_by_az.private : x.id]
-  # The transgit gateway route table ids 
+  # The transgit gateway route table ids
   public_route_table_ids = var.public_subnet_netmask > 0 ? [for k, x in module.vpc.rt_attributes_by_type_by_az.public : x.id] : []
-  # A map of the route table ids for the transit gateway by az 
-  transit_route_table_by_az = var.enable_transit_gateway ? { for k, v in module.vpc.rt_attributes_by_type_by_az.transit_gateway : k => v.id } : {}
+  # A map of the route table ids for the transit gateway by az
+  transit_route_table_by_az = local.enable_transit_gateway ? { for k, v in module.vpc.rt_attributes_by_type_by_az.transit_gateway : k => v.id } : {}
 
   subnets = merge(
     local.private_subnet,
@@ -71,8 +75,9 @@ locals {
 
   # A list of the private endpoints to enable ssm
   ssm_endpoints = var.enable_ssm ? ["ssmmessages", "ssm", "ec2messages"] : []
-  # enabled_endpotints is a list of all the private endpoints to enable 
+  # enabled_endpotints is a list of all the private endpoints to enable
   enabled_endpoints = concat(var.enable_private_endpoints, local.ssm_endpoints)
-  ## Build the list of resolver rules to associate with the vpc 
+  ## Build the list of resolver rules to associate with the vpc
   resolver_rules = var.enable_route53_resolver_rules ? [for id in data.aws_route53_resolver_rules.current.resolver_rule_ids : id if !contains(var.exclude_route53_resolver_rules, id)] : []
-}
+}
+