Terraform Modules

Use existing HCL modules within your TypeScript configuration.

tfts allows you to consume existing Terraform modules (HCL) using the TerraformHclModule class. This enables you to leverage the vast ecosystem of community-maintained modules while still writing your infrastructure in TypeScript.

Using a Module

To use a module, you provide its source, version, and any required variables.

import { TerraformHclModule } from "tfts";

const vpc = new TerraformHclModule(stack, "vpc", {
  source: "terraform-aws-modules/vpc/aws",
  version: "5.0.0",
  variables: {
    name: "my-vpc",
    cidr: "10.0.0.0/16",
    azs: ["us-east-1a", "us-east-1b"],
    public_subnets: ["10.0.1.0/24", "10.0.2.0/24"],
  },
});

Managing Variables and Providers

You can set variables after initialization using the set method:

vpc.set("enable_nat_gateway", true);

If the module requires specific providers, you can pass them in the configuration:

const vpc = new TerraformHclModule(stack, "vpc", {
  source: "terraform-aws-modules/vpc/aws",
  providers: [awsProvider],
  variables: { /* ... */ },
});

Accessing Outputs

Modules often expose outputs that you need to use in other parts of your configuration. TerraformHclModule provides typed methods to access these outputs.

const vpcId = vpc.get("vpc_id");
const publicSubnets = vpc.getList("public_subnets");
const vpcCidr = vpc.getString("vpc_cidr_block");

Available methods:

• get(outputName): Returns a generic token.
• getString(outputName): Returns a string token.
• getNumber(outputName): Returns a number token.
• getBoolean(outputName): Returns a boolean token.
• getList(outputName): Returns a list token.

Example: VPC and EC2

const vpc = new TerraformHclModule(stack, "vpc", {
  source: "terraform-aws-modules/vpc/aws",
  version: "5.0.0",
  variables: {
    name: "my-vpc",
    cidr: "10.0.0.0/16",
    // ...
  },
});

new Instance(stack, "web", {
  ami: "ami-123456",
  instanceType: "t2.micro",
  subnetId: vpc.getList("public_subnets")[0],
});

Using TerraformHclModule is the fastest way to integrate complex, pre-built infrastructure components into your tfts project.