terraform-aws-vpc

A Terraform base module for managing an Amazon Virtual Private Cloud on Amazon Web Services (AWS).

This module supports Terraform v0.15, v0.14, v0.13, as well as v0.12.20 and above and is compatible with the terraform AWS provider v3 as well as v2.45 and above.

This module is part of our Infrastructure as Code (IaC) framework that enables our users and customers to easily deploy and manage reusable, secure, and production-grade cloud infrastructure.

• Module Features
• Getting Started
• Module Argument Reference
  • Main Resource Configuration
    • VPC
  • Extended Resource Configuration
    • Subnets
    • Internet Gateway
    • NAT Gateways
    • Subnet Routing
• Module Configuration
• Module Outputs
  • Computed Attributes
  • Full Resource Objects
  • Module Attributes
• External Documentation
  • AWS Documentation VPC
  • Terraform AWS Provider Documentation:
• Module Versioning
  • Backwards compatibility in 0.0.z and 0.y.z version
• About Mineiros
• Reporting Issues
• Contributing
• Makefile Targets
• License

Module Features

This module implements the following Terraform resources

• aws_region
• aws_vpc
• aws_subnet
• aws_eip
• aws_nat_gateway
• aws_route_table
• aws_route_table_association
• aws_route
• aws_internet_gateway
• aws_route_table
• aws_route_table_association
• aws_route
• aws_elasticache_subnet_group
• aws_db_subnet_group

Getting Started

Most basic usage just setting required arguments:

module "terraform-aws-vpc" {
  source  = "mineiros-io/vpc/aws"
  version = "~> 0.7.0"
}

Module Argument Reference

See variables.tf and examples/ for details and use-cases.

Main Resource Configuration

VPC

• vpc_name: (Optional string)

  The name of the VPC. This will be used to tag resources with names by default.

  Default is "main".

• cidr_block: (Optional string)

  The CIDR block for the VPC.

  Default is "10.0.0.0/16".

• instance_tenancy: (Optional string)

  A tenancy option for instances launched into the VPC. Setting the tenancy to dedicated will create additional costs: See https://aws.amazon.com/ec2/pricing/dedicated-instances/ for details.

  Default is "default".

• enable_dns_support: (Optional bool)

  A boolean flag to enable/disable DNS support in the VPC.

  Default is true.

• enable_dns_hostnames: (Optional bool)

  A boolean flag to enable/disable DNS hostnames in the VPC.

  Default is false.

• enable_classiclink: (Optional bool)

  A boolean flag to enable/disable ClassicLink for the VPC. Only valid in regions and accounts that support EC2 Classic. See the ClassicLink documentation for more information.

  Default is false.

• enable_classiclink_dns_support: (Optional bool)

  A boolean flag to enable/disable ClassicLink DNS Support for the VPC. Only valid in regions and accounts that support EC2 Classic.

  Default is false.

• assign_generated_ipv6_cidr_block: (Optional bool)

  Requests an Amazon-provided IPv6 CIDR block with a /56 prefix length for the VPC. You cannot specify the range of IP addresses, or the size of the CIDR block.

  Default is false.

• vpc_tags: (Optional string)

  A map of tags to assign to the vpc resource. To set the Name and add the capability to be used in data sources the vpc_tags will always be merged with:

  Default is "{}".

  Example:

  {
    Name                           = "{vpc_name}"
    "mineiros-io/aws/vpc/vpc-name" = "{vpc_name}"
  }

Extended Resource Configuration

Subnets

• subnets: (Optional list(subnet))

  A List of subnet objects that defined the subnet setup within the VPC.

  Default is [].

  Example:

  subnets = [
    {
      group = "main"
      class = "public"
  
      map_public_ip_on_launch = true
  
      cidr_block = cidrsubnet("10.0.0.0/16", 4, 0)
      newbits    = 4
  
      netnums_by_az = {
        a = [0] # "10.0.0.0/24"
        b = [1] # "10.0.1.0/24"
      }
      tags = {}
    },
    {
      group = "main"
      class = "private"
  
      map_public_ip_on_launch = false
  
      cidr_block = cidrsubnet("10.0.0.0/16", 4, 1)
      newbits    = 4
  
      netnums_by_az = {
        a = [0] # "10.0.16.0/24"
        b = [1] # "10.0.17.0/24"
      }
    },
  ]

  Each subnet object in the list accepts the following attributes:

  • group: (Optional string)

    A group name for the subnets. This can be any string. This information is used to group and tag resources within the subnets. The combination of group and class needs to be unique over all subnets defined. This can be changed at any time and will change the tags applied to resources by default.

    Default is "main".

  • class: (Optional string)

    The class of the subnet. This can be "public", "private", or "intra". This can be changed at any time and will change the routing of the subnet instead of recreating the subnet resource.

    • "public" defines a set of subnets where deployed components are reachable via the public Internet.
    • "private" defines a set of subnets where components are not publicly reachable but can reach the Internet.
    • "intra" defines a set of subnets that have no connectivity to the public Internet.

    Default is "private".

  • map_public_ip_on_launch: (Optional bool)

    Whether resources deployed into the subnet will be assigned a public IPv4 address when launched.

    Default is true.

  • cidr_block: (Optional string)

    Define the base CIDR Block of the subnets and the parameters to calculate each CIDR Block.

    Default is the CIDR Block of the VPC (cidr_block).

  • newbits: (Optional number)

    How many bits should be added when calculating the subnets CIDR Blocks.

    Default is 8.

  • netnums_by_az: (Required map(netnums_by_az))

    Type is map(list(number)).

    A map of subnets keyed by availability zone suffix (a,b,c,d,e,f). The numbers define the network number with in the CIDR Block. See https://www.terraform.io/docs/configuration/functions/cidrsubnet.html for details on how this is calculated internally.

    Note: When adjusting cidr_block or newbits you might also need to adjust the netnums. The example shows how to deploy one subnet in availability zone a (10.0.0.0/24) and one subnet in availability zone b (10.0.1.0/24).

    Example:

    cidr_block = "10.0.0.0/16"
    newbits    = 8
    
    netnums_by_az = {
      a = [0] # "10.0.0.0/24"
      b = [1] # "10.0.1.0/24"
    }

  • db_subnet_group_name: (Optional string)

    The name of a db subnet group to create for all netnum ranges in this subnet. The db_subnet_group_name resource tags will be cloned from the subnets.

  • elasticache_subnet_group_name: (Optional string)

    The name of a elasticache subnet group to create for all netnum ranges in this subnet. The elasticache_subnet_group_name resource tags will be cloned from the subnets.

  • tags: (Optional map(string))

    A map of tags that will be applied to each subnet in this group-class combination. Those tags will be merged with a Name tag, module_tags, subnet_tags and tags for the subnet class public_subnet_tags, private_subnet_tags, or intra_subnet_tags.

    To set the Name and add the capability to be used in data sources the subnet_tags will always be merged with:

    {
      Name                               = "{vpc_name}-{subnet.group}-{subnet.class}-{az}-{idx}"
      "mineiros-io/aws/vpc/vpc-name"     = "{vpc_name}"
      "mineiros-io/aws/vpc/subnet-name"  = "{vpc_name}-{subnet.group}-{subnet.class}-{az}-{idx}"
      "mineiros-io/aws/vpc/subnet-group" = "{subnet.group}"
      "mineiros-io/aws/vpc/subnet-class" = "{subnet.class}"
    }

    Default is {}.

• subnet_tags: (Optional map(string))

  Tags applied to each subnet resource.

  Default is {}.

• public_subnet_tags: (Optional map(string))

  Tags applied to each public subnet.

  Default is {}.

• private_subnet_tags: (Optional map(string))

  Tags applied to each private subnet.

  Default is {}.

• intra_subnet_tags: (Optional map(string))

  Tags applied to each intra subnet.

  Default is {}.

Internet Gateway

• internet_gateway_tags: (Optional map(string))

  A map of tags to apply to the created Internet Gateway. An Internet Gateway is created if a public subnet is defined. All public egress and ingress traffic of all public subnets will be routed through the same Internet Gateway.

  To set the Name and add the capability to be used in data sources the internet_gateway_tags will always be merged with:

  {
    Name                           = "{vpc_name}"
    "mineiros-io/aws/vpc/vpc-name" = "{vpc_name}"
    "mineiros-io/aws/vpc/igw-name" = "{vpc_name}"
  }

  Default is {}.

NAT Gateways

A Note on pricing: AWS charges for each provisioned NAT Gateway. Please see https://aws.amazon.com/vpc/pricing/ for details. To save costs you can use nat_gateway_mode to define the number of NAT Gateways you want to deploy. The best practice is to deploy one NAT Gateway per Availability Zone for higher reliability on production environments (one_per_az), while you can save some costs on staging and testing environments by deploying a single NAT Gateway (single).

• nat_gateway_mode: (Optional string)

  Set the mode for the NAT Gateways. NAT Gateways will only be created when private subnets are defined. Each private subnet needs at least one configured public subnet in the same availability zone. Each NAT gateway will be assigned an Elastic IP Address. When changing the mode, NAT Gateways and Elastic IP Addresses will be created or destroyed. All public egress traffic of all private subnets will be routed through the same set of NAT Gateways. Possible modes are none, single, or one_per_az. Choose

  • "none" to create no NAT Gateways at all (use for debugging only),
  • "single" to create a single NAT Gateway inside the first defined Public Subnet, or
  • "one_per_az" to create one NAT Gateway inside the first Public Subnet in each Availability Zone.

  Default is "single".

• nat_gateway_single_mode_zone: (Optional string)

  Define the zone (short name) of the NAT gateway when nat_gateway_mode is "single" (e.g. "a", "b", or "c"). The AWS region will be added as a prefix.

  Default is "a random zone".

• nat_gateway_eip_allocation_ids: (Optional map(string))

  A map of EIP allocation ids to use for nat gateways keyed by short zone name (e.g. "a", "b", or "c"). If set no EIPs will be created by the module. If unset, the module will create the needed number of EIPs.

  Default is {}.

• nat_gateway_tags: (Optional map(string))

  A map of tags to apply to the created NAT Gateways.

  To set the Name and add the capability to be used in data sources the nat_gateway_tags will always be merged with:

  {
    Name                             = "{vpc_name}-{zone}"
    "mineiros-io/aws/vpc/vpc-name"   = "{vpc_name}"
    "mineiros-io/aws/vpc/natgw-name" = "{vpc_name}-{zone}"
  }

  Default is {}.

• eip_tags: (Optional map(string))

  A map of tags to apply to the created NAT Gateway Elastic IP Addresses.

  To set the Name and add the capability to be used in data sources the eip_tags will always be merged with:

  {
    Name                             = "{vpc_name}-nat-private-{zone}"
    "mineiros-io/aws/vpc/vpc-name"   = "{vpc_name}"
    "mineiros-io/aws/vpc/natgw-name" = "{vpc_name}-{zone}"
    "mineiros-io/aws/vpc/eip-name"   = "{vpc_name}-nat-private-{zone}"
  }

  Default is {}.

Subnet Routing

• route_table_tags: (Optional map(string))

  A map of tags to apply to all created Route Tables.

  Default is {}.

• public_route_table_tags: (Optional map(string))

  A map of tags to apply to the created Public Route Tables.

  To set the Name and add the capability to be used in data sources the public_route_table_tags will always be merged with:

  {
    Name                                   = "{vpc_name}-public-{group}"
    "mineiros-io/aws/vpc/vpc-name"         = "{vpc_name}"
    "mineiros-io/aws/vpc/routetable-name"  = "{vpc_name}-public-{group}"
    "mineiros-io/aws/vpc/routetable-class" = "public"
  }

  Default is {}.

• private_route_table_tags: (Optional map(string))

  A map of tags to apply to the created Private Route Tables.

  To set the Name and add the capability to be used in data sources the private_route_table_tags will always be merged with:

  {
    Name                                   = "{vpc_name}-private-{group}-{zone}"
    "mineiros-io/aws/vpc/vpc-name"         = "{vpc_name}"
    "mineiros-io/aws/vpc/routetable-name"  = "{vpc_name}-private-{group}-{zone}"
    "mineiros-io/aws/vpc/routetable-class" = "private"
  }

  Default is {}.

• intra_route_table_tags: (Optional map(string))

  A map of tags to apply to the created Intra Route Tables.

  To set the Name and add the capability to be used in data sources the intra_route_table_tags will always be merged with:

  {
    Name                                   = "{vpc_name}-intra-{group}"
    "mineiros-io/aws/vpc/vpc-name"         = "{vpc_name}"
    "mineiros-io/aws/vpc/routetable-name"  = "{vpc_name}-intra-{group}"
    "mineiros-io/aws/vpc/routetable-class" = "intra"
  }

  Default is {}.

Module Configuration

• module_enabled: (Optional bool)

  Specifies whether resources in the module will be created.

  Default is true.

• module_tags: (Optional map(string))

  A map of tags that will be applied to all created resources that accept tags. Tags defined with 'module_tags' can be overwritten by resource-specific tags.

  Default is {}.

• module_depends_on: (Optional list(dependency))

  A list of dependencies. Any object can be assigned to this list to define a hidden external dependency.

Module Outputs

The following attributes are exported by the module:

Computed Attributes

• public_subnets_by_group: (map(public_subnets_by_group))

  A map of lists of public subnets keyed by group. (aws_subnet)

• public_route_table_ids_by_group: (map(public_route_table_ids_by_group))

  A map of lists of public route table IDs keyed by group.

• public_subnet_ids_by_group: (map(public_subnet_ids_by_group))

  A map of lists of public subnet IDs keyed by group.

• private_subnets_by_group: (map(private_subnets_by_group))

  A map of lists of private subnets keyed by group. (aws_subnet)

• private_route_table_ids_by_group: (map(private_route_table_ids_by_group))

  A map of lists of private route table IDs keyed by group.

• private_subnet_ids_by_group: (map(private_subnet_ids_by_group))

  A map of lists of private subnet IDs keyed by group.

• intra_subnets_by_group: (map(intra_subnets_by_group))

  A map of lists of intra aws_subnet keyed by group. (aws_subnet)

• intra_route_table_ids_by_group: (map(intra_route_table_ids_by_group))

  A map of lists of intra route table IDs keyed by group.

• intra_subnet_ids_by_group: (map(intra_subnet_ids_by_group))

  A map of lists of intra subnet IDs keyed by group.

Full Resource Objects

• vpc: (object(vpc))

  The VPC. (aws_vpc)

• intra_route_tables: (map(intra_route_tables))

  A map of intra route tables keyed by group. (aws_route_table)

• intra_route_table_associations: (map(intra_route_table_associations))

  A map of intra route table associations keyed by the subnets CIDR Blocks. (aws_route_table_association)

• eips: (map(eips))

  A map of Elastic IP Adresses (EIPs) keyed by availability zone. (aws_eip)

• nat_gateways: (map(nat_gateways))

  A map of NAT gatweways keyed by availability zone. (aws_nat_gateway)

• private_route_tables: (map(private_route_tables))

  A map of private route tables keyed by group. (aws_route_table)

• private_route_table_associations: (map(private_route_table_associations))

  A map of private route table associations keyed by the subnets CIDR Blocks. (aws_route_table_association)

• routes_to_nat_gateways: (map(routes_to_nat_gateways))

  A map of routes to the NAT Gateways keyed by group. (aws_route)

• internet_gateway: (object(internet_gateway))

  The Internet Gateway. (aws_internet_gateway)

• public_route_tables: (map(public_route_tables))

  A map of public route tables keyed by group. (aws_route_table)

• public_route_table_associations: (map(public_route_table_associations))

  A map of public route table associations keyed by the subnets CIDR Blocks. (aws_route_table_association)

• routes_to_internet_gateway: (map(routes_to_internet_gateway))

  A map of routes to the Internet Gateway keyed by group. (aws_route)

• subnets: (map(subnets))

  A map of subnets keyed by CIDR Blocks. (aws_subnet)

Module Attributes

• module_inputs: (map(module_inputs))

  A map of all module arguments. Set to the provided values or calculated default values.

• module_enabled: (bool)

  Whether this module is enabled.

• module_tags: (map(string))

  The map of tags that are being applied to all created resources that accept tags.

External Documentation

AWS Documentation VPC

• https://aws.amazon.com/de/vpc/

Terraform AWS Provider Documentation:

• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/vpc
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/subnet
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/internet_gateway
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/nat_gateway
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route_table
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route_table_association
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route

Module Versioning

This Module follows the principles of Semantic Versioning (SemVer).

Given a version number MAJOR.MINOR.PATCH, we increment the:

1. MAJOR version when we make incompatible changes,
2. MINOR version when we add functionality in a backwards compatible manner, and
3. PATCH version when we make backwards compatible bug fixes.

Backwards compatibility in 0.0.z and 0.y.z version

• Backwards compatibility in versions 0.0.z is not guaranteed when z is increased. (Initial development)
• Backwards compatibility in versions 0.y.z is not guaranteed when y is increased. (Pre-release)

About Mineiros

Mineiros is a remote-first company headquartered in Berlin, Germany that solves development, automation and security challenges in cloud infrastructure.

Our vision is to massively reduce time and overhead for teams to manage and deploy production-grade and secure cloud infrastructure.

We offer commercial support for all of our modules and encourage you to reach out if you have any questions or need help. Feel free to email us at hello@mineiros.io or join our Community Slack channel.

Reporting Issues

We use GitHub Issues to track community reported issues and missing features.

Contributing

Contributions are always encouraged and welcome! For the process of accepting changes, we use Pull Requests. If you'd like more information, please see our Contribution Guidelines.

Makefile Targets

This repository comes with a handy Makefile. Run make help to see details on each available target.

License

This module is licensed under the Apache License Version 2.0, January 2004. Please see LICENSE for full details.

Copyright © 2019-2022 Mineiros GmbH