Transit Gateway Attachment Terraform Module
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
Name | Version |
---|---|
terraform | >= 1.0.0 |
aws | >= 4.5.0 |
Providers
Name | Version |
---|---|
aws | >= 4.5.0 |
Modules
No modules.
Resources
Name | Type |
---|---|
aws_ec2_transit_gateway_vpc_attachment.this | resource |
Inputs
Name | Description | Type | Default | Required |
---|---|---|---|---|
custom_tags | 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. | map(string) | {} | no |
enable_appliance_mode_support | 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. | bool | false | no |
enable_dns_support | Whether DNS resolution is enabled for this VPC attachment. The default is false. | bool | false | no |
enable_ipv6_support | 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. | bool | false | no |
enable_transit_gateway_default_route_table_association | Whether the VPC attachment should be associated with the Transit Gateway association default route table. The default is true. | bool | true | no |
enable_transit_gateway_default_route_table_propagation | Whether the VPC attachment should propagate routes with the Transit Gateway propagation default route table. The default is true. | bool | true | no |
transit_gateway_id | EC2 Transit Gateway identifier | string | n/a | yes |
vpcs | 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({<br> vpc_id = string<br> vpc_name = string<br> subnet_ids = list(string)<br> })) | n/a | yes |
Outputs
Name | Description |
---|---|
id | EC2 Transit Gateway Attachment identifier. |
Sample Usage
- Terraform
- Terragrunt
# ------------------------------------------------------------------------------------------------------
# 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=v0.28.0"
# ----------------------------------------------------------------------------------------------------
# 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 with optional creation of routing tables. See variable
# definition for details
vpcs = <map(object(
vpc_id = string
vpc_name = string
subnet_ids = list(string)
appliance_mode_support = optional(string, "disable")
route_table = optional(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 propagate routes with the Transit Gateway
# propagation non-default route tables. The default is false.
enable_tgw_route_propagation = 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
}
# ------------------------------------------------------------------------------------------------------
# DEPLOY GRUNTWORK'S TRANSIT-GATEWAY-ATTACHMENT MODULE
# ------------------------------------------------------------------------------------------------------
terraform {
source = "git::git@github.com:gruntwork-io/terraform-aws-vpc.git//modules/transit-gateway-attachment?ref=v0.28.0"
}
inputs = {
# ----------------------------------------------------------------------------------------------------
# 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 with optional creation of routing tables. See variable
# definition for details
vpcs = <map(object(
vpc_id = string
vpc_name = string
subnet_ids = list(string)
appliance_mode_support = optional(string, "disable")
route_table = optional(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 propagate routes with the Transit Gateway
# propagation non-default route tables. The default is false.
enable_tgw_route_propagation = 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
- Inputs
- Outputs
Required
transit_gateway_id
stringEC2 Transit Gateway identifier
vpcs
map(object(…))A map of vpcs with their name and the subnet ids that the transit gateway will attach to with optional creation of routing tables. See variable definition for details
map(object({
vpc_id = string
vpc_name = string
subnet_ids = list(string)
# 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.
# Valid values: enable, disable. Default value: disable.
appliance_mode_support = optional(string, "disable")
# Creates and associates a route table with the transit gateway attachment. Default value: null
route_table = optional(string)
}))
Details
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.
Valid values: enable, disable. Default value: disable.
Details
Creates and associates a route table with the transit gateway attachment. Default value: null
Optional
custom_tags
map(string)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
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 propagate routes with the Transit Gateway propagation non-default route tables. 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
EC2 Transit Gateway Attachment identifier.
The IDs of the Transit Gateway Route Tables.