AWS components¶

All components within an AWS-based MACH composer configuration are automatically considered to have a 'aws' integration by default. Only if 'aws' is explicitly omitted from the integrations definition, it won't require any AWS-specific variables.

To be able to create the resources needed, a couple of extra Terraform variables are set by MACH composer.

In addition to this, the component itself is responsible for packaging and deploying the correct assets in case of a Lambda function.

Terraform variables¶

In addition to the base variables AWS components don't require additional variables, unless an endpoint is expected (and set in the configuration).

With `endpoints`¶

In order to support the endpoints attribute on the component, the component needs to define what endpoints it expects.

For example, if the component requires two endpoints (main and webhooks) to be set, the following variables needs to be defined:

variable "aws_endpoint_main" {
  type = object({
    url                       = string
    api_gateway_id            = string
    api_gateway_execution_arn = string
  })
}

variable "aws_endpoint_webhooks" {
  type = object({
    url                       = string
    api_gateway_id            = string
    api_gateway_execution_arn = string
  })
}

Packaging and deploying¶

AWS Lambda functions need to be uploaded to a S3 bucket. From there AWS Lambda will run the functions for you once instructed by the Terraform deployment.

Configure runtime¶

When defining your AWS Lambda function resource, you can reference back to the asset that is deployed:

resource "aws_lambda_function" "example" {
  s3_bucket = "your-lambda-repo"
  s3_key    = "yourcomponent-${var.component_version}.zip"
  ...
}

HTTP routing¶

MACH composer will provide the correct HTTP routing for you.
To do so, the following has to be configured:

endpoints settings in the Site configuration
The component needs to have endpoints defined

Default endpoint

If you assign default to one of your components endpoints, no additional Route53 settings are needed.

MACH composer will create an API Gateway for you without any custom domain.

More information in the deployment section.

Lambda function¶

We recommend using the AWS Lambda Terraform module for managing a Lambda function.

module "lambda_function" {
  source = "terraform-aws-modules/lambda/aws"

  function_name = "${var.site}-${var.azure_short_name}"
  handler       = "src/index.handler"
  runtime       = "nodejs12.x"
  memory_size   = 512
  timeout       = 10

  environment_variables = local.environment_variables
  create_package = false
  s3_existing_package = {
    bucket = local.lambda_s3_repository
    key    = local.lambda_s3_key
  }
}