terraform-aws-named-subnets

Terraform module for named subnets provisioning.

This project is part of our comprehensive "SweetOps" approach towards DevOps.

It's 100% Open Source and licensed under the APACHE2.

We literally have hundreds of terraform modules that are Open Source and well-maintained. Check them out!

Security & Compliance

Security scanning is graciously provided by Bridgecrew. Bridgecrew is the leading fully hosted, cloud-native solution providing continuous Terraform security and compliance.

Benchmark	Description
	Infrastructure Security Compliance
	Center for Internet Security, KUBERNETES Compliance
	Center for Internet Security, AWS Compliance
	Center for Internet Security, AZURE Compliance
	Payment Card Industry Data Security Standards Compliance
	National Institute of Standards and Technology Compliance
	Information Security Management System, ISO/IEC 27001 Compliance
	Service Organization Control 2 Compliance
	Center for Internet Security, GCP Compliance
	Health Insurance Portability and Accountability Compliance

Usage

IMPORTANT: We do not pin modules to versions in our examples because of the difficulty of keeping the versions in the documentation in sync with the latest released versions. We highly recommend that in your code you pin the version to the exact version you are using so that your infrastructure remains stable, and update versions in a systematic way so that they do not catch you by surprise.

Also, because of a bug in the Terraform registry (hashicorp/terraform#21417), the registry shows many of our inputs as required when in fact they are optional. The table below correctly indicates which inputs are required.

Simple example, with private and public subnets in one Availability Zone:

module "vpc" {
  source = "cloudposse/vpc/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace  = "eg"
  name       = "vpc"
  stage      = "dev"
  cidr_block = var.cidr_block
}

locals {
  public_cidr_block  = cidrsubnet(module.vpc.vpc_cidr_block, 1, 0)
  private_cidr_block = cidrsubnet(module.vpc.vpc_cidr_block, 1, 1)
}

module "public_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["web1", "web2", "web3"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.public_cidr_block
  type              = "public"
  igw_id            = module.vpc.igw_id
  availability_zone = "us-east-1a"
}

module "private_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "database"
  subnet_names      = ["kafka", "cassandra", "zookeeper"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.private_cidr_block
  type              = "private"
  availability_zone = "us-east-1a"
  ngw_id            = module.public_subnets.ngw_id
}

Simple example, with ENI as default route gateway for private subnets

resource "aws_network_interface" "default" {
  subnet_id         = module.us_east_1b_public_subnets.subnet_ids[0]
  source_dest_check = false
  tags              = module.network_interface_label.id
}

module "us_east_1b_private_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["charlie", "echo", "bravo"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.us_east_1b_private_cidr_block
  type              = "private"
  availability_zone = "us-east-1b"
  eni_id            = aws_network_interface.default.id
  attributes        = ["us-east-1b"]
}

Full example, with private and public subnets in two Availability Zones for High Availability:

module "vpc" {
  source = "cloudposse/vpc/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace  = "eg"
  name       = "vpc"
  stage      = "dev"
  cidr_block = var.cidr_block
}

locals {
  us_east_1a_public_cidr_block  = cidrsubnet(module.vpc.vpc_cidr_block, 2, 0)
  us_east_1a_private_cidr_block = cidrsubnet(module.vpc.vpc_cidr_block, 2, 1)
  us_east_1b_public_cidr_block  = cidrsubnet(module.vpc.vpc_cidr_block, 2, 2)
  us_east_1b_private_cidr_block = cidrsubnet(module.vpc.vpc_cidr_block, 2, 3)
}

module "us_east_1a_public_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["apples", "oranges", "grapes"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.us_east_1a_public_cidr_block
  type              = "public"
  igw_id            = module.vpc.igw_id
  availability_zone = "us-east-1a"
  attributes        = ["us-east-1a"]
}

module "us_east_1a_private_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["charlie", "echo", "bravo"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.us_east_1a_private_cidr_block
  type              = "private"
  availability_zone = "us-east-1a"
  ngw_id            = module.us_east_1a_public_subnets.ngw_id
  attributes        = ["us-east-1a"]
}

module "us_east_1b_public_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["apples", "oranges", "grapes"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.us_east_1b_public_cidr_block
  type              = "public"
  igw_id            = module.vpc.igw_id
  availability_zone = "us-east-1b"
  attributes        = ["us-east-1b"]
}

module "us_east_1b_private_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["charlie", "echo", "bravo"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.us_east_1b_private_cidr_block
  type              = "private"
  availability_zone = "us-east-1b"
  ngw_id            = module.us_east_1b_public_subnets.ngw_id
  attributes        = ["us-east-1b"]
}

resource "aws_network_interface" "default" {
  subnet_id         = module.us_east_1b_public_subnets.subnet_ids[0]
  source_dest_check = false
  tags              = module.network_interface_label.id
}

module "us_east_1b_private_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["charlie", "echo", "bravo"]
  vpc_id            = module.vpc.vpc_id
  cidr_block        = local.us_east_1b_private_cidr_block
  type              = "private"
  availability_zone = "us-east-1b"
  eni_id            = aws_network_interface.default.id
  attributes        = ["us-east-1b"]
}

Caveat

You must use only one type of device for a default route gateway per route table. ENI or NGW

Given the following configuration (see the Simple example above)

locals {
  public_cidr_block  = cidrsubnet(var.vpc_cidr, 1, 0)
  private_cidr_block = cidrsubnet(var.vpc_cidr, 1, 1)
}

module "public_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "app"
  subnet_names      = ["web1", "web2", "web3"]
  vpc_id            = var.vpc_id
  cidr_block        = local.public_cidr_block
  type              = "public"
  availability_zone = "us-east-1a"
  igw_id            = var.igw_id
}

module "private_subnets" {
  source = "cloudposse/named-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"
  namespace         = "eg"
  stage             = "dev"
  name              = "database"
  subnet_names      = ["kafka", "cassandra", "zookeeper"]
  vpc_id            = var.vpc_id
  cidr_block        = local.private_cidr_block
  type              = "private"
  availability_zone = "us-east-1a"
  ngw_id            = module.public_subnets.ngw_id
}

output "private_named_subnet_ids" {
  value = module.private_subnets.named_subnet_ids
}

output "public_named_subnet_ids" {
  value = module.public_subnets.named_subnet_ids
}

the output Maps of subnet names to subnet IDs look like these

public_named_subnet_ids = {
  web1 = subnet-ea58d78e
  web2 = subnet-556ee131
  web3 = subnet-6f54db0b
}
private_named_subnet_ids = {
  cassandra = subnet-376de253
  kafka = subnet-9e53dcfa
  zookeeper = subnet-a86fe0cc
}

and the created subnet IDs could be found by the subnet names using map["key"] or lookup(map, key, [default]),

for example:

public_named_subnet_ids["web1"]

lookup(private_named_subnet_ids, "kafka")

Makefile Targets

Available targets:

  help                                Help screen
  help/all                            Display help for all targets
  help/short                          This help short screen
  lint                                Lint terraform code

Requirements

Name	Version
terraform	>= 0.13.0
aws	>= 2.0
null	>= 2.0

Providers

Name	Version
aws	>= 2.0

Modules

Name	Source	Version
private_label	cloudposse/label/null	0.24.1
public_label	cloudposse/label/null	0.24.1
this	cloudposse/label/null	0.24.1

Resources

Name	Type
aws_eip.default	resource
aws_nat_gateway.default	resource
aws_network_acl.private	resource
aws_network_acl.public	resource
aws_route.private	resource
aws_route.public	resource
aws_route_table.private	resource
aws_route_table.public	resource
aws_route_table_association.private	resource
aws_route_table_association.public	resource
aws_subnet.private	resource
aws_subnet.public	resource
aws_vpc.default	data source

Inputs

Name	Description	Type	Default	Required
additional_tag_map	Additional tags for appending to tags_as_list_of_maps. Not added to `tags`.	`map(string)`	`{}`	no
attributes	Additional attributes (e.g. `1`)	`list(string)`	`[]`	no
availability_zone	Availability Zone	`string`	n/a	yes
cidr_block	Base CIDR block which will be divided into subnet CIDR blocks (e.g. `10.0.0.0/16`)	`string`	n/a	yes
context	Single object for setting entire context at once. See description of individual variables for details. Leave string and numeric variables as `null` to use default value. Individual variable settings (non-null) override settings in context object, except for attributes, tags, and additional_tag_map, which are merged.	`any`	{ "additional_tag_map": {}, "attributes": [], "delimiter": null, "enabled": true, "environment": null, "id_length_limit": null, "label_key_case": null, "label_order": [], "label_value_case": null, "name": null, "namespace": null, "regex_replace_chars": null, "stage": null, "tags": {} }	no
delimiter	Delimiter to be used between `namespace`, `environment`, `stage`, `name` and `attributes`. Defaults to `-` (hyphen). Set to `""` to use no delimiter at all.	`string`	`null`	no
enabled	Set to false to prevent the module from creating any resources	`bool`	`null`	no
eni_id	An ID of a network interface which is used as a default route in private route tables (_e.g._ `eni-9c26a123`). Conflicts with `ngw_id`.	`string`	`""`	no
environment	Environment, e.g. 'uw2', 'us-west-2', OR 'prod', 'staging', 'dev', 'UAT'	`string`	`null`	no
id_length_limit	Limit `id` to this many characters (minimum 6). Set to `0` for unlimited length. Set to `null` for default, which is `0`. Does not affect `id_full`.	`number`	`null`	no
igw_id	Internet Gateway ID which will be used as a default route in public route tables (e.g. `igw-9c26a123`).	`string`	`""`	no
label_key_case	The letter case of label keys (`tag` names) (i.e. `name`, `namespace`, `environment`, `stage`, `attributes`) to use in `tags`. Possible values: `lower`, `title`, `upper`. Default value: `title`.	`string`	`null`	no
label_order	The naming order of the id output and Name tag. Defaults to ["namespace", "environment", "stage", "name", "attributes"]. You can omit any of the 5 elements, but at least one must be present.	`list(string)`	`null`	no
label_value_case	The letter case of output label values (also used in `tags` and `id`). Possible values: `lower`, `title`, `upper` and `none` (no transformation). Default value: `lower`.	`string`	`null`	no
map_public_ip_on_launch_enabled	Enable/disable map_public_ip_on_launch subnet attribute.	`bool`	`false`	no
max_subnets	Maximum number of subnets which can be created. This variable is being used for CIDR blocks calculation. Defaults to length of `subnet_names` argument	`number`	`16`	no
name	Solution name, e.g. 'app' or 'jenkins'	`string`	`null`	no
namespace	Namespace, which could be your organization name or abbreviation, e.g. 'eg' or 'cp'	`string`	`null`	no
nat_enabled	Enable/disable NAT Gateway	`bool`	`true`	no
ngw_id	NAT Gateway ID which will be used as a default route in private route tables (e.g. `igw-9c26a123`). Conflicts with `eni_id`.	`string`	`""`	no
private_network_acl_egress	Private network egress ACL rules	list(object( { rule_no = number action = string cidr_block = string from_port = number to_port = number protocol = string }))	[ { "action": "allow", "cidr_block": "0.0.0.0/0", "from_port": 0, "protocol": "-1", "rule_no": 100, "to_port": 0 } ]	no
private_network_acl_id	Network ACL ID that will be added to the subnets. If empty, a new ACL will be created	`string`	`""`	no
private_network_acl_ingress	Private network ingress ACL rules	list(object( { rule_no = number action = string cidr_block = string from_port = number to_port = number protocol = string }))	[ { "action": "allow", "cidr_block": "0.0.0.0/0", "from_port": 0, "protocol": "-1", "rule_no": 100, "to_port": 0 } ]	no
public_network_acl_egress	Public network egress ACL rules	list(object( { rule_no = number action = string cidr_block = string from_port = number to_port = number protocol = string }))	[ { "action": "allow", "cidr_block": "0.0.0.0/0", "from_port": 0, "protocol": "-1", "rule_no": 100, "to_port": 0 } ]	no
public_network_acl_id	Network ACL ID that will be added to the subnets. If empty, a new ACL will be created	`string`	`""`	no
public_network_acl_ingress	Public network ingress ACL rules	list(object( { rule_no = number action = string cidr_block = string from_port = number to_port = number protocol = string }))	[ { "action": "allow", "cidr_block": "0.0.0.0/0", "from_port": 0, "protocol": "-1", "rule_no": 100, "to_port": 0 } ]	no
regex_replace_chars	Regex to replace chars with empty string in `namespace`, `environment`, `stage` and `name`. If not set, `"/[^a-zA-Z0-9-]/"` is used to remove all characters other than hyphens, letters and digits.	`string`	`null`	no
stage	Stage, e.g. 'prod', 'staging', 'dev', OR 'source', 'build', 'test', 'deploy', 'release'	`string`	`null`	no
subnet_names	List of subnet names (e.g. `['apples', 'oranges', 'grapes']`)	`list(string)`	n/a	yes
tags	Additional tags (e.g. `map('BusinessUnit','XYZ')`	`map(string)`	`{}`	no
type	Type of subnets (`private` or `public`)	`string`	`"private"`	no
vpc_id	VPC ID	`string`	n/a	yes

Outputs

Name	Description
named_subnet_ids	Map of subnet names to subnet IDs
ngw_id	NAT Gateway ID
ngw_private_ip	Private IP address of the NAT Gateway
ngw_public_ip	Public IP address of the NAT Gateway
route_table_ids	Route table IDs
subnet_ids	Subnet IDs

Share the Love

Like this project? Please give it a ★ on our GitHub! (it helps us a lot)

Are you using this project or any of our other projects? Consider leaving a testimonial. =)

Related Projects

Check out these related projects.

terraform-aws-multi-az-subnets - Terraform module for multi-AZ public and private subnets provisioning.
terraform-aws-dynamic-subnets - Terraform module for public and private subnets provisioning in existing VPC
terraform-aws-vpc - Terraform Module that defines a VPC with public/private subnets across multiple AZs with Internet Gateways
terraform-aws-cloudwatch-flow-logs - Terraform module for enabling flow logs for vpc and subnets.

Help

Got a question? We got answers.

File a GitHub issue, send us an email or join our Slack Community.

DevOps Accelerator for Startups

We are a DevOps Accelerator. We'll help you build your cloud infrastructure from the ground up so you can own it. Then we'll show you how to operate it and stick around for as long as you need us.

Work directly with our team of DevOps experts via email, slack, and video conferencing.

We deliver 10x the value for a fraction of the cost of a full-time engineer. Our track record is not even funny. If you want things done right and you need it done FAST, then we're your best bet.

Reference Architecture. You'll get everything you need from the ground up built using 100% infrastructure as code.
Release Engineering. You'll have end-to-end CI/CD with unlimited staging environments.
Site Reliability Engineering. You'll have total visibility into your apps and microservices.
Security Baseline. You'll have built-in governance with accountability and audit logs for all changes.
GitOps. You'll be able to operate your infrastructure via Pull Requests.
Training. You'll receive hands-on training so your team can operate what we build.
Questions. You'll have a direct line of communication between our teams via a Shared Slack channel.
Troubleshooting. You'll get help to triage when things aren't working.
Code Reviews. You'll receive constructive feedback on Pull Requests.
Bug Fixes. We'll rapidly work with you to fix any bugs in our projects.

Slack Community

Join our Open Source Community on Slack. It's FREE for everyone! Our "SweetOps" community is where you get to talk with others who share a similar vision for how to rollout and manage infrastructure. This is the best place to talk shop, ask questions, solicit feedback, and work together as a community to build totally sweet infrastructure.

Discourse Forums

Participate in our Discourse Forums. Here you'll find answers to commonly asked questions. Most questions will be related to the enormous number of projects we support on our GitHub. Come here to collaborate on answers, find solutions, and get ideas about the products and services we value. It only takes a minute to get started! Just sign in with SSO using your GitHub account.

Sign up for our newsletter that covers everything on our technology radar. Receive updates on what we're up to on GitHub as well as awesome new projects we discover.

Office Hours

Join us every Wednesday via Zoom for our weekly "Lunch & Learn" sessions. It's FREE for everyone!

Contributing

Bug Reports & Feature Requests

Please use the issue tracker to report any bugs or file feature requests.

Developing

If you are interested in being a contributor and want to get involved in developing this project or help out with our other projects, we would love to hear from you! Shoot us an email.

In general, PRs are welcome. We follow the typical "fork-and-pull" Git workflow.

Fork the repo on GitHub
Clone the project to your own machine
Commit changes to your own branch
Push your work back up to your fork
Submit a Pull Request so that we can review your changes

NOTE: Be sure to merge the latest changes from "upstream" before making a pull request!

Copyright

License

See LICENSE for full details.

Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.

Trademarks

All other trademarks referenced herein are the property of their respective owners.

About

This project is maintained and funded by Cloud Posse, LLC. Like it? Please let us know by leaving a testimonial!

We're a DevOps Professional Services company based in Los Angeles, CA. We ❤️ Open Source Software.

We offer paid support on all of our projects.

Check out our other projects, follow us on twitter, apply for a job, or hire us to help with your cloud strategy and implementation.

Contributors

Erik Osterman	Andriy Knysh	Sergey Vasilyev	Vladimir	Konstantin B

3h4x / terraform-aws-named-subnets

terraform-aws-named-subnets

Security & Compliance

Usage

Caveat

Makefile Targets

Requirements

Providers

Modules

Resources

Inputs

Outputs

Share the Love

Related Projects

Help

DevOps Accelerator for Startups

Slack Community

Discourse Forums

Newsletter

Office Hours

Contributing

Bug Reports & Feature Requests

Developing

Copyright

License

Trademarks

About

Contributors

About

Languages