AWS ApiGateway Custom Lambda Authorizer

This is a Proof of Concept for AWS ApiGateway using a Custom Lambda Authorizer for the endpoints.

The terraform code creates all the needed infrastructure:

• two lambdas
• one Api Gateway configured with a lambda as a custom authorizer and the other lambda as an endpoint
• IAM roles and policies for Lambdas and Api Gateway

To set it up:

terraform init
terraform plan
terraform apply

After the infra resources are created, run a curl command using the api_endpoint output from the terraform :

curl -s https://<api_endpoint> -H 'Authorization: some payload'

Example:

curl -s https://1234567890.execute-api.us-east-1.amazonaws.com/poc_api_auth/demo -H 'Authorization: some payload' | jq .
{
  "Region ": "us-east-1",
  "Client_Payload": "some payload",
  "Principal_ID": "e2bf74b4792e4d0b84acb843c8b3be79"
}

Lambda Event Payload is configured as TOKEN.

Token authorizers are the most straight-forward. You specify the name of a header, usually Authorization, that is used to authenticate your request. The value of this header is passed into your custom authorizer for your authorizer to validate.

To destroy the created resources from AWS:

terraform destroy