terraform-aws-arc-transit-gateway ¶

Module: sourcefuse/arc-transit-gateway/aws

Registry: https://registry.terraform.io/modules/sourcefuse/arc-transit-gateway/aws

Category: Networking / Transit

Source: https://github.com/sourcefuse/terraform-aws-arc-transit-gateway

Tip

🤖 New: Use this module with AI assistants via the ARC IaC MCP Server — search, scaffold, and security-scan ARC modules from natural language. Quick setup ↓

Overview¶

Creates AWS Transit Gateway with VPC attachments, route table associations, and cross-account sharing via Resource Access Manager.

Architecture¶

Architecture Diagram

What It Does¶

Transit Gateway with configurable ASN and routing options
VPC attachments with subnet configuration
Route table associations and propagations
Cross-account sharing via AWS RAM
Static routes for custom routing
DNS support and multicast configuration

Quickstart¶

module "tgw" {
  source  = "sourcefuse/arc-transit-gateway/aws"
  version = "1.0.0"

  namespace   = "myapp"
  environment = "prod"

  create_transit_gateway = true
  transit_gateway_name   = "myapp-prod-tgw"

  vpc_attachments = {
    "spoke-vpc" = {
      vpc_id     = data.aws_vpc.spoke.id
      subnet_ids = data.aws_subnets.private.ids
    }
  }

  tags = { Environment = "prod" }
}

Required Inputs¶

Name	Type	Description
`namespace`	`string`	Namespace prefix
`environment`	`string`	Deployment environment
## Key Outputs

Name	Description
`transit_gateway_id`	Transit Gateway ID
`transit_gateway_arn`	Transit Gateway ARN
`vpc_attachment_ids`	Map of VPC attachment IDs
## Full Variable & Output Reference

The complete inputs/outputs reference is auto-generated below.

Requirements¶

Name	Version
terraform	~> 1.3, < 2.0.0
aws	~> 5.0
random	~> 3.0

Providers¶

Name	Version
aws	5.64.0
aws.target	5.64.0

Modules¶

No modules.

Resources¶

Name	Type
aws_ec2_transit_gateway.this	resource
aws_ec2_transit_gateway_vpc_attachment.source	resource
aws_ec2_transit_gateway_vpc_attachment.this	resource
aws_ec2_transit_gateway_vpc_attachment_accepter.this	resource
aws_ram_principal_association.target_account	resource
aws_ram_resource_association.transit_gateway	resource
aws_ram_resource_share.transit_gateway	resource
aws_ram_resource_share_accepter.transit_gateway	resource
aws_route.source	resource
aws_route.this	resource
aws_ec2_transit_gateway.this	data source
aws_vpc.source_vpc	data source
aws_vpc.target_vpc	data source

Inputs¶

Name	Description	Type	Default	Required
allow_external_principals	Indicates whether external principals (accounts outside the organization) are allowed.	`bool`	`true`	no
auto_accept_shared_attachments	Whether resource attachment requests are automatically accepted	`string`	`"disable"`	no
create_transit_gateway	n/a	`bool`	`true`	no
create_transit_gateway_attacment_in_source_account	n/a	`bool`	`true`	no
default_route_table_association	Whether resource attachments are associated with the default route table	`string`	`"enable"`	no
default_route_table_propagation	Whether resource attachments automatically propagate routes to the default route table	`string`	`"enable"`	no
dns_support	Enable or disable DNS support	`string`	`"enable"`	no
existing_transit_gateway_id	n/a	`string`	`null`	no
source_attachment_dns_support	Enable or disable DNS support	`string`	`"enable"`	no
source_attachment_ipv6_support	Enable or disable IPv6 support	`string`	`"disable"`	no
source_attachment_name	The name tag for the source Transit Gateway VPC attachment.	`string`	`"TransitGateway-VPC-Attachment-Source"`	no
source_cidr_block	Destination CIDR block for the route	`string`	`null`	no
source_route_table_ids	Route table ID to add routes to	`list(any)`	`[]`	no
source_subnet_ids	List of subnet IDs for the Transit Gateway VPC attachment	`list(string)`	`[]`	no
source_vpc_id	The VPC ID for the Transit Gateway VPC attachment	`string`	`null`	no
tags	A map of tags to assign to the resource.	`map(string)`	`{}`	no
target_account_id	The AWS Account ID where the Transit Gateway is shared	`list(any)`	n/a	yes
target_attachment_dns_support	Enable or disable DNS support	`string`	`"enable"`	no
target_attachment_ipv6_support	Enable or disable IPv6 support	`string`	`"disable"`	no
target_attachment_name	The name tag for the target Transit Gateway VPC attachment.	`string`	`"TransitGateway-VPC-Attachment-Target"`	no
target_cidr_block	Destination CIDR block for the route	`string`	`null`	no
target_route_table_ids	Route table ID to add routes to	`list(any)`	n/a	yes
target_subnet_ids	List of subnet IDs for the Transit Gateway VPC attachment	`list(string)`	n/a	yes
target_vpc_id	The VPC ID for the Transit Gateway VPC attachment	`string`	n/a	yes
transit_gateway_asn	Amazon side ASN for the Transit Gateway	`number`	`64512`	no
transit_gateway_name	Name of the Transit Gateway	`string`	`"Transit-GW"`	no
transit_gateway_share_name	The name of the Transit Gateway resource share.	`string`	`"transit-gateway-share"`	no
vpn_ecmp_support	Enable or disable Equal Cost Multipath support for VPN	`string`	`"enable"`	no

Outputs¶

Name	Description
transit_gateway_arn	The ARN of the Transit Gateway
transit_gateway_id	The ID of the Transit Gateway

Versioning¶

This project uses a .version file at the root of the repo which the pipeline reads from and does a git tag.

When you intend to commit to main, you will need to increment this version. Once the project is merged, the pipeline will kick off and tag the latest git commit.

Development¶

Prerequisites¶

Configurations¶

Configure pre-commit hooks
1
pre-commit install

Versioning¶

while Contributing or doing git commit please specify the breaking change in your commit message whether its major,minor or patch

For Example

git commit -m "your commit message #major"

By specifying this , it will bump the version and if you don't specify this in your commit message then by default it will consider patch and will bump that accordingly

Tests¶

Tests are available in test directory

Configure the dependencies

cd test/
go mod init github.com/sourcefuse/terraform-aws-refarch-<module_name>
go get github.com/gruntwork-io/terratest/modules/terraform

Now execute the test
1
go test -timeout 30m

AI Assistant Integration (ARC IaC MCP)¶

The ARC IaC MCP Server is a hosted Model Context Protocol service that lets AI assistants browse, search, scaffold, compare, and security-scan any of the SourceFuse ARC Terraform modules — directly from natural language.

What you can do with it:

Discover — search and filter modules by keyword or AWS resource type.
Understand — get inputs, outputs, and resources for any module without leaving your editor.
Scaffold — generate production-ready, multi-file Terraform with cross-module wiring already done.
Secure — scan generated or existing HCL for misconfigurations before it hits a PR.
Compare — diff modules side-by-side to make informed architectural decisions.

Setup (one minute)¶

The MCP endpoint is https://arc-iac-mcp.sourcef.us/mcp. Pick your client:

Claude Code CLI:

claude mcp add arc-iac --transport http https://arc-iac-mcp.sourcef.us/mcp

Claude Desktop — edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "arc-iac": {
      "url": "https://arc-iac-mcp.sourcef.us/mcp"
    }
  }
}

Cursor / Windsurf / Kiro — add the same block to .cursor/mcp.json (or the equivalent for your client).

Example prompts to try¶

"List all ARC modules sorted by downloads"
"What inputs does arc-ecs require?"
"Scaffold a production-ready arc-db Aurora setup with Secrets Manager"
"Compare arc-eks and arc-ecs for running 10 microservices"
"Scan this Terraform before I raise a PR: <paste HCL>"

See the ARC IaC MCP repo for the full tool reference, troubleshooting tips, and local-development instructions.

Contributing¶

See CONTRIBUTING.md for commit conventions and development setup.

Authors¶

This project is authored by: - SourceFuse ARC Team

terraform-aws-arc-transit-gateway¶

Overview¶

Architecture¶

What It Does¶

Quickstart¶

Required Inputs¶

Requirements¶

Providers¶

Modules¶

Resources¶

Inputs¶

Outputs¶

Versioning¶

Development¶

Prerequisites¶

Configurations¶

Versioning¶

Tests¶

AI Assistant Integration (ARC IaC MCP)¶

Setup (one minute)¶

Example prompts to try¶

Contributing¶

Authors¶

terraform-aws-arc-transit-gateway ¶