UPD: moved random into a module

tf-modulised/vpc-subnets/random/main.tf

@@ -0,0 +1,17 @@
+resource "random_string" "string" {
+  length  = 4
+  special = false
+}
+
+resource "random_integer" "number" {
+  min     = 1000
+  max     = 9999
+}
+
+output "string" {
+	value = random_string.string.result
+}
+
+output "number" {
+	value = random_integer.number.result
+}

tf-modulised/vpc-subnets/vpc.tf

@@ -1,25 +1,19 @@
 data "aws_availability_zones" "available" {}
 
-#resource "random_string" "suffix" {
+module "random" {
-#  length  = 4
+  source = "./random"
-#  special = false
-#}
-
-resource "random_integer" "suffix" {
-  min     = 1000
-  max     = 9999
 }
 
 module "vpc" {
   source  = "terraform-aws-modules/vpc/aws"
   version = "2.6.0"
 
-  name                 = "demo-vpc-${random_integer.suffix.result}"
+  name                 = "demo-vpc-${module.random.number}"
   cidr                 = "172.16.0.0/16"
   azs                  = data.aws_availability_zones.available.names
   private_subnets 	= cidrsubnets("172.16.18.0/23", 1, 1)
   public_subnets 	= cidrsubnets("172.16.20.0/23", 1, 1)
-  enable_nat_gateway   = true
+  enable_nat_gateway   = false
   single_nat_gateway   = true
   enable_dns_hostnames = true