terraform-aws-lambda-at-edge-cognito-authentication

This terraform module creates a Lambda@Edge Lambda to be used within a viewer policy of a CloudFront Distribution to enforce Cognito Authentication through a configured Cognito User Pool.

How it Works

Requirements

• Terraform version >= 1.0.X
• NodeJS + NPM (compatible with NodeJS 18.X.X)
  • Used for npm ci dependency installation for Lambda@Edge Bundle.
• Terraform AWS Provider in us-east-1
  • Requirement for CloudFront + Lambda@Edge runtime.
• Existing Cognito User Pool and User Pool Client.

Usage

To use this module, source it into one your Terraform project like so:

data "aws_cognito_user_pools" "user_pool" {
  name     = "my_cognito_pool_name"
}

resource "aws_cognito_user_pool_client" "cognito_client" {
  ...
}

module "cloudfront_cognito_auth_lambda" {
  source    = "git::https://github.com/disney/terraform-aws-lambda-at-edge-cognito-authentication.git?ref=<version-ref>"
  name                                      = "my-application"
  cognito_user_pool_name                    = data.aws_cognito_user_pools.user_pool.name
  cognito_user_pool_region                  = "us-east-1"
  cognito_user_pool_id                      = aws_cognito_user_pool_client.cognito_client.user_pool_id
  cognito_user_pool_app_client_id           = aws_cognito_user_pool_client.cognito_client.id

  tags = { foo = "bar" }
}

You can use the output of this module to pass as a rule on your CloudFront distribution cache on viewer-requests (typically on an S3 Bucket Origin with an OAI).

resource "aws_cloudfront_distribution" "my_cloudfront_distribution" {
  ...

  ordered_cache_behavior {
    ...
    lambda_function_association {
      event_type   = "viewer-request"
      lambda_arn   = module.cloudfront_cognito_auth_lambda.qualified_arn
    }
  }
}

Lambda@Edge Destroy Issue

Note that if a destroy action is performed on this terraform module, terraform is unable to delete the Lambda@Edge that was published as a part of this infrastructure (This is noted by this issue on the Terraform provider). It will only be removed from the terraform state as the skip_destroy flag is set to true.

In order to properly delete this resource, it should be manually cleaned up, instructions here.

Requirements

Name	Version
terraform	~> 1.0
aws	>= 4.57

Providers

Name	Version
archive	2.4.0
aws	5.26.0
null	3.2.2

Modules

No modules.

Resources

Name	Type
aws_iam_role.lambda_at_edge	resource
aws_kms_key.ssm_kms_key	resource
aws_lambda_function.cloudfront_auth_edge	resource
aws_ssm_parameter.lambda_configuration_parameters	resource
null_resource.install_lambda_dependencies	resource
archive_file.lambda_edge_bundle	data source
aws_caller_identity.current	data source
aws_iam_policy_document.allow_lambda_service_assume	data source
aws_region.current	data source

Inputs

Name	Description	Type	Default	Required
cognito_additional_settings	Map of any to configure any additional cognito@edge parameters not handled by this module.	any	{}	no
cognito_cookie_expiration_days	Number of days to keep the cognito cookie valid.	number	7	no
cognito_disable_cookie_domain	Sets domain attribute in cookies, defaults to false.	bool	false	no
cognito_log_level	Logging level. Default: 'silent'	string	"silent"	no
cognito_redirect_path	Optional path to redirect to after a successful cognito login.	string	""	no
cognito_user_pool_app_client_id	Cognito User Pool App Client ID for the targeted user pool.	string	n/a	yes
cognito_user_pool_app_client_secret	Cognito User Pool App Client Secret for the targeted user pool. NOTE: This is currently not compatible with AppSync applications.	string	null	no
cognito_user_pool_domain	Optional: Full Domain of the Cognito User Pool to utilize. Mutually exclusive with 'cognito_user_pool_name'.	string	""	no
cognito_user_pool_id	Cognito User Pool ID for the targeted user pool.	string	n/a	yes
cognito_user_pool_name	Name of the Cognito User Pool to utilize. Required if 'cognito_user_pool_domain' is not set.	string	""	no
cognito_user_pool_region	AWS region where the cognito user pool was created.	string	"us-west-2"	no
lambda_runtime	Lambda runtime to utilize for Lambda@Edge.	string	"nodejs20.x"	no
lambda_timeout	Amount of timeout in seconds to set on for Lambda@Edge.	number	5	no
name	Name to prefix on all infrastructure created by this module.	string	n/a	yes
tags	Map of tags to attach to all AWS resources created by this module.	map(string)	{}	no

Outputs

Name	Description
arn	ARN for the Lambda@Edge created by this module.
qualified_arn	Qualified ARN for the Lambda@Edge created by this module.