Terraform module for multi-AZ subnets provisioning.
The module creates private and public subnets in the provided Availability Zones.
The public subnets are routed to the Internet Gateway specified by var.igw_id.
nat_gateway_enabled flag controls the creation of NAT Gateways in the public subnets.
The private subnets are routed to the NAT Gateways provided in the var.az_ngw_ids map.
Example of terraform apply outputs
module "vpc" {
source = "git::https://github.com/ceibo-it/terraform-aws-vpc.git?ref=0.0.1"
namespace = var.namespace
stage = var.stage
name = var.name
cidr_block = var.cidr_block
}
module "public_subnets" {
source = "git::https://github.com/ceibo-it/terraform-aws-subnets.git?ref=0.0.1"
namespace = var.namespace
stage = var.stage
name = var.name
availability_zones = ["us-east-2a", "us-east-2b", "us-east-2c"]
vpc_id = module.vpc.vpc_id
cidr_blocks = ["10.0.0.0/24", "10.0.1.0/24", "10.0.2.0/24"]
type = "public"
igw_id = module.vpc.igw_id
nat_gateway_enabled = "true"
}
module "private_subnets" {
source = "git::https://github.com/ceibo-it/terraform-aws-subnets.git?ref=0.0.1"
namespace = var.namespace
stage = var.stage
name = var.name
availability_zones = ["us-east-2a", "us-east-2b", "us-east-2c"]
vpc_id = module.vpc.vpc_id
cidr_blocks = ["10.0.10.0/24", "10.0.11.0/24", "10.0.12.0/24"]
type = "private"
az_ngw_ids = module.public_subnets.az_ngw_ids
}Given the following configuration
module "vpc" {
source = "git::https://github.com/ceibo-it/terraform-aws-vpc.git?ref=0.0.1"
namespace = var.namespace
name = "vpc"
stage = var.stage
cidr_block = var.cidr_block
}
module "public_subnets" {
source = "git::https://github.com/ceibo-it/terraform-aws-multi-az-subnets.git?ref=0.0.1"
namespace = var.namespace
stage = var.stage
name = var.name
availability_zones = ["us-east-2a", "us-east-2b", "us-east-2c"]
vpc_id = module.vpc.vpc_id
cidr_blocks = ["10.0.0.0/24", "10.0.1.0/24", "10.0.2.0/24"]
type = "public"
igw_id = module.vpc.igw_id
nat_gateway_enabled = "true"
}
module "private_subnets" {
source = "git::https://github.com/ceibo-it/terraform-aws-multi-az-subnets.git?ref=0.0.1"
namespace = var.namespace
stage = var.stage
name = var.name
availability_zones = ["us-east-2a", "us-east-2b", "us-east-2c"]
vpc_id = module.vpc.vpc_id
cidr_blocks = ["10.0.10.0/24", "10.0.11.0/24", "10.0.12.0/24"]
type = "private"
az_ngw_ids = module.public_subnets.az_ngw_ids
}
output "private_az_subnet_ids" {
value = module.private_subnets.az_subnet_ids
}
output "public_az_subnet_ids" {
value = module.public_subnets.az_subnet_ids
}the output Maps of AZ names to subnet IDs look like these
public_az_subnet_ids = {
us-east-2a = subnet-ea58d78e
us-east-2b = subnet-556ee131
us-east-2c = subnet-6f54db0b
}
private_az_subnet_ids = {
us-east-2a = subnet-376de253
us-east-2b = subnet-9e53dcfa
us-east-2c = subnet-a86fe0cc
}and the created subnet IDs could be found by the AZ names using map["key"] or lookup(map, key, [default]),
for example:
public_az_subnet_ids["us-east-2a"]
lookup(private_az_subnet_ids, "us-east-2b")
| Name | Description | Type | Default | Required |
|---|---|---|---|---|
| attributes | Additional attributes (e.g. policy or role) |
list(string) | <list> |
no |
| availability_zones | List of Availability Zones (e.g. ['us-east-1a', 'us-east-1b', 'us-east-1c']) |
list(string) | - | yes |
| az_ngw_ids | Only for private subnets. Map of AZ names to NAT Gateway IDs that are used as default routes when creating private subnets | map(string) | <map> |
no |
| cidr_blocks | List of CIDR blocks corresponding with each Availability Zone (e.g. ['10.0.0.0/24', '10.0.1.0/24', '10.0.2.0/24']) |
string | - | yes |
| delimiter | Delimiter to be used between namespace, stage, name and attributes |
string | - |
no |
| enabled | Set to false to prevent the module from creating any resources | string | true |
no |
| igw_id | Internet Gateway ID that is used as a default route when creating public subnets (e.g. igw-9c26a123) |
string | `` | no |
| max_subnets | Maximum number of subnets that can be created. The variable is used for CIDR blocks calculation | string | 6 |
no |
| name | Application or solution name | string | - | yes |
| namespace | Namespace (e.g. cp or cloudposse) |
string | - | yes |
| nat_gateway_enabled | Flag to enable/disable NAT Gateways creation in public subnets | string | true |
no |
| private_network_acl_egress | Egress network ACL rules | list(map(string)) | <list> |
no |
| private_network_acl_id | Network ACL ID that is added to the private subnets. If empty, a new ACL will be created | string | `` | no |
| private_network_acl_ingress | Egress network ACL rules | list(map(string)) | <list> |
no |
| public_network_acl_egress | Egress network ACL rules | list(map(string)) | <list> |
no |
| public_network_acl_id | Network ACL ID that is added to the public subnets. If empty, a new ACL will be created | string | `` | no |
| public_network_acl_ingress | Egress network ACL rules | list(map(string)) | <list> |
no |
| stage | Stage (e.g. prod, dev, staging) |
string | - | yes |
| tags | Additional tags (e.g. map(BusinessUnit,XYZ) |
map(string) | <map> |
no |
| type | Type of subnets to create (private or public) |
string | private |
no |
| vpc_id | VPC ID | string | - | yes |
| Name | Description |
|---|---|
| az_ngw_ids | Map of AZ names to NAT Gateway IDs (only for public subnets) |
| az_route_table_ids | Map of AZ names to Route Table IDs |
| az_subnet_arns | Map of AZ names to subnet ARNs |
| az_subnet_ids | Map of AZ names to subnet IDs |
Copyright © 2020 Ceibo
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terraform-aws-subnets Copyright 2020 Ceibo
This product includes software developed by Cloud Posse, LLC (c) (https://cloudposse.com/) Licensed under Apache License, Version 2.0 Copyright © 2017-2019 Cloud Posse, LLC