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VPC Modules 0.26.17Last updated in version 0.26.8

Transit Gateway Attachment Terraform Module

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This module creates a transit gateway attachment resource. A transit gateway attachment, attaches the transit gateway to a VPC. This module can be used to attach a transit gateway to multiple VPCs. Attaching a transit gateway to one or more VPCs creates a HUB and spoke routing topology, allowing traffic from one VPC to reach other VPCs or from a VPC to reach on-premises networks.

The module accepts a map of VPCs for attachment to the transit gateway. See the examples below for the structure of the map.

See VPC Core Concepts for more information on the core networking components and topologies.

What is a Transit Gateway Attachment?

A transit gateway attachment is a way to connect a transit gateway (virtual router) to a VPC. You can think of a VPC attachment just like a cat5e or cat6 network cable. By attaching the transit gateway, you're connecting the cable between the virtual router and a VPC. By attaching the transit gateway and then either configuring a route or enabling route propagation, you can route traffic between VPCs.

Usage

For usage examples, check out the examples folder.

Requirements

NameVersion
terraform>= 1.0.0
aws>= 4.5.0

Providers

NameVersion
aws>= 4.5.0

Modules

No modules.

Resources

NameType
aws_ec2_transit_gateway_vpc_attachment.thisresource

Inputs

NameDescriptionTypeDefaultRequired
custom_tagsA map of tags to apply to all resources when applicable. The key is the tag name and the value is the tag value. Note that the tag 'Name' is automatically added by this module but may be optionally overwritten by this variable.map(string){}no
enable_appliance_mode_supportWhether Appliance Mode support is enabled. If enabled, a traffic flow between a source and destination uses the same Availability Zone for the VPC attachment for the lifetime of that flow. The default is false.boolfalseno
enable_dns_supportWhether DNS resolution is enabled for this VPC attachment. The default is false.boolfalseno
enable_ipv6_supportWhether IPv6 support is enabled. If enabled, a private IPv6 address from the Amazon pool of IPv6 addresses is assigned to the Elastic Network Interface (ENI) for a VPC attachment. The default is false.boolfalseno
enable_transit_gateway_default_route_table_associationWhether the VPC attachment should be associated with the Transit Gateway association default route table. The default is true.booltrueno
enable_transit_gateway_default_route_table_propagationWhether the VPC attachment should propagate routes with the Transit Gateway propagation default route table. The default is true.booltrueno
transit_gateway_idEC2 Transit Gateway identifierstringn/ayes
vpcsA map of vpcs with their name and the subnet ids that the transit gateway will attach to. The subnet IDs configured here are the attachment point for the transit gateway. I.E. The transit gateway will have an IP on these subnets.map(object({<br> vpc_id = string<br> vpc_name = string<br> subnet_ids = list(string)<br> }))n/ayes

Outputs

NameDescription
idEC2 Transit Gateway Attachment identifier.

Sample Usage

main.tf

# ------------------------------------------------------------------------------------------------------
# DEPLOY GRUNTWORK'S TRANSIT-GATEWAY-ATTACHMENT MODULE
# ------------------------------------------------------------------------------------------------------

module "transit_gateway_attachment" {

source = "git::git@github.com:gruntwork-io/terraform-aws-vpc.git//modules/transit-gateway-attachment?ref=v0.26.17"

# ----------------------------------------------------------------------------------------------------
# REQUIRED VARIABLES
# ----------------------------------------------------------------------------------------------------

# EC2 Transit Gateway identifier
transit_gateway_id = <string>

# A map of vpcs with their name and the subnet ids that the transit gateway
# will attach to. The subnet IDs configured here are the attachment point for
# the transit gateway. I.E. The transit gateway will have an IP on these
# subnets.
vpcs = <map(object(
vpc_id = string
vpc_name = string
subnet_ids = list(string)
))>

# ----------------------------------------------------------------------------------------------------
# OPTIONAL VARIABLES
# ----------------------------------------------------------------------------------------------------

# A map of tags to apply to all resources when applicable. The key is the tag
# name and the value is the tag value. Note that the tag 'Name' is
# automatically added by this module but may be optionally overwritten by this
# variable.
custom_tags = {}

# Whether Appliance Mode support is enabled. If enabled, a traffic flow
# between a source and destination uses the same Availability Zone for the VPC
# attachment for the lifetime of that flow. The default is false.
enable_appliance_mode_support = false

# Whether DNS resolution is enabled for this VPC attachment. The default is
# false.
enable_dns_support = false

# Whether IPv6 support is enabled. If enabled, a private IPv6 address from the
# Amazon pool of IPv6 addresses is assigned to the Elastic Network Interface
# (ENI) for a VPC attachment. The default is false.
enable_ipv6_support = false

# Whether the VPC attachment should be associated with the Transit Gateway
# association default route table. The default is true.
enable_transit_gateway_default_route_table_association = true

# Whether the VPC attachment should propagate routes with the Transit Gateway
# propagation default route table. The default is true.
enable_transit_gateway_default_route_table_propagation = true

}


Reference

Required

transit_gateway_idstringrequired

EC2 Transit Gateway identifier

vpcsmap(object(…))required

A map of vpcs with their name and the subnet ids that the transit gateway will attach to. The subnet IDs configured here are the attachment point for the transit gateway. I.E. The transit gateway will have an IP on these subnets.

map(object({
vpc_id = string
vpc_name = string
subnet_ids = list(string)
}))

Optional

custom_tagsmap(string)optional

A map of tags to apply to all resources when applicable. The key is the tag name and the value is the tag value. Note that the tag 'Name' is automatically added by this module but may be optionally overwritten by this variable.

{}

Whether Appliance Mode support is enabled. If enabled, a traffic flow between a source and destination uses the same Availability Zone for the VPC attachment for the lifetime of that flow. The default is false.

false
enable_dns_supportbooloptional

Whether DNS resolution is enabled for this VPC attachment. The default is false.

false

Whether IPv6 support is enabled. If enabled, a private IPv6 address from the Amazon pool of IPv6 addresses is assigned to the Elastic Network Interface (ENI) for a VPC attachment. The default is false.

false

Whether the VPC attachment should be associated with the Transit Gateway association default route table. The default is true.

true

Whether the VPC attachment should propagate routes with the Transit Gateway propagation default route table. The default is true.

true