Added support for both types of values in azs (names and ids) (#370)

.pre-commit-config.yaml

 repos:
 - repo: git://github.com/antonbabenko/pre-commit-terraform
-  rev: v1.24.0
+  rev: v1.26.0
   hooks:
     - id: terraform_fmt
     - id: terraform_docs
 - repo: git://github.com/pre-commit/pre-commit-hooks
-  rev: v2.4.0
+  rev: v2.5.0
   hooks:
     - id: check-merge-conflict

examples/simple-vpc/README.md

@@ -4,6 +4,10 @@ Configuration in this directory creates set of VPC resources which may be suffic
 
 There is a public and private subnet created per availability zone in addition to single NAT Gateway shared between all 3 availability zones.
 
+This configuration uses Availability Zone IDs and Availability Zone names for demonstration purposes. Normally, you need to specify only names or IDs.
+
+[Read more about AWS regions, availability zones and local zones](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-regions-availability-zones).
+
 ## Usage
 
 To run this example you need to execute:

examples/simple-vpc/main.tf

@@ -14,7 +14,7 @@ module "vpc" {
 
   cidr = "10.0.0.0/16"
 
-  azs             = ["eu-west-1a", "eu-west-1b", "eu-west-1c"]
+  azs             = ["eu-west-1a", "eu-west-1b", "euw1-az3"]
   private_subnets = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
   public_subnets  = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]
 

main.tf

@@ -285,7 +285,8 @@ resource "aws_subnet" "public" {
 
   vpc_id                          = local.vpc_id
   cidr_block                      = element(concat(var.public_subnets, [""]), count.index)
-  availability_zone               = element(var.azs, count.index)
+  availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null
+  availability_zone_id            = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) == 0 ? element(var.azs, count.index) : null
   map_public_ip_on_launch         = var.map_public_ip_on_launch
   assign_ipv6_address_on_creation = var.public_subnet_assign_ipv6_address_on_creation == null ? var.assign_ipv6_address_on_creation : var.public_subnet_assign_ipv6_address_on_creation
 
@@ -312,7 +313,8 @@ resource "aws_subnet" "private" {
 
   vpc_id                          = local.vpc_id
   cidr_block                      = var.private_subnets[count.index]
-  availability_zone               = element(var.azs, count.index)
+  availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null
+  availability_zone_id            = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) == 0 ? element(var.azs, count.index) : null
   assign_ipv6_address_on_creation = var.private_subnet_assign_ipv6_address_on_creation == null ? var.assign_ipv6_address_on_creation : var.private_subnet_assign_ipv6_address_on_creation
 
   ipv6_cidr_block = var.enable_ipv6 && length(var.private_subnet_ipv6_prefixes) > 0 ? cidrsubnet(aws_vpc.this[0].ipv6_cidr_block, 8, var.private_subnet_ipv6_prefixes[count.index]) : null
@@ -338,7 +340,8 @@ resource "aws_subnet" "database" {
 
   vpc_id                          = local.vpc_id
   cidr_block                      = var.database_subnets[count.index]
-  availability_zone               = element(var.azs, count.index)
+  availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null
+  availability_zone_id            = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) == 0 ? element(var.azs, count.index) : null
   assign_ipv6_address_on_creation = var.database_subnet_assign_ipv6_address_on_creation == null ? var.assign_ipv6_address_on_creation : var.database_subnet_assign_ipv6_address_on_creation
 
   ipv6_cidr_block = var.enable_ipv6 && length(var.database_subnet_ipv6_prefixes) > 0 ? cidrsubnet(aws_vpc.this[0].ipv6_cidr_block, 8, var.database_subnet_ipv6_prefixes[count.index]) : null
@@ -380,7 +383,8 @@ resource "aws_subnet" "redshift" {
 
   vpc_id                          = local.vpc_id
   cidr_block                      = var.redshift_subnets[count.index]
-  availability_zone               = element(var.azs, count.index)
+  availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null
+  availability_zone_id            = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) == 0 ? element(var.azs, count.index) : null
   assign_ipv6_address_on_creation = var.redshift_subnet_assign_ipv6_address_on_creation == null ? var.assign_ipv6_address_on_creation : var.redshift_subnet_assign_ipv6_address_on_creation
 
   ipv6_cidr_block = var.enable_ipv6 && length(var.redshift_subnet_ipv6_prefixes) > 0 ? cidrsubnet(aws_vpc.this[0].ipv6_cidr_block, 8, var.redshift_subnet_ipv6_prefixes[count.index]) : null
@@ -422,7 +426,8 @@ resource "aws_subnet" "elasticache" {
 
   vpc_id                          = local.vpc_id
   cidr_block                      = var.elasticache_subnets[count.index]
-  availability_zone               = element(var.azs, count.index)
+  availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null
+  availability_zone_id            = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) == 0 ? element(var.azs, count.index) : null
   assign_ipv6_address_on_creation = var.elasticache_subnet_assign_ipv6_address_on_creation == null ? var.assign_ipv6_address_on_creation : var.elasticache_subnet_assign_ipv6_address_on_creation
 
   ipv6_cidr_block = var.enable_ipv6 && length(var.elasticache_subnet_ipv6_prefixes) > 0 ? cidrsubnet(aws_vpc.this[0].ipv6_cidr_block, 8, var.elasticache_subnet_ipv6_prefixes[count.index]) : null
@@ -456,7 +461,8 @@ resource "aws_subnet" "intra" {
 
   vpc_id                          = local.vpc_id
   cidr_block                      = var.intra_subnets[count.index]
-  availability_zone               = element(var.azs, count.index)
+  availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null
+  availability_zone_id            = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) == 0 ? element(var.azs, count.index) : null
   assign_ipv6_address_on_creation = var.intra_subnet_assign_ipv6_address_on_creation == null ? var.assign_ipv6_address_on_creation : var.intra_subnet_assign_ipv6_address_on_creation
 
   ipv6_cidr_block = var.enable_ipv6 && length(var.intra_subnet_ipv6_prefixes) > 0 ? cidrsubnet(aws_vpc.this[0].ipv6_cidr_block, 8, var.intra_subnet_ipv6_prefixes[count.index]) : null

variables.tf

@@ -239,7 +239,7 @@ variable "create_database_nat_gateway_route" {
 }
 
 variable "azs" {
-  description = "A list of availability zones in the region"
+  description = "A list of availability zones names or ids in the region"
   type        = list(string)
   default     = []
 }