subdomain-redirect

subdomain-redirect

AWS Lambda function to redirect a domain to its subdomain or parent domain.
Meant to be used with Amazon API Gateway.

Setup

Function configuration

Add the function code to AWS Lambda with the following configuration options:

Key	Value
Runtime	Node.js 6.10
Handler	index.handler
Role	AWSLambdaBasicExecutionRole
Memory	128 (MB)
Timeout	3 sec

Environment variables

Set the following optional environment variables for the Lambda function:

Key	Value
label	The DNS label of the subdomain, defaults to "www".
status	The status code of the response, defaults to 302.
scheme	The scheme of the redirect URL, defaults to "https".
hsts	The value for the HSTS header, by default empty.
type	The value for the Content-Type header, defaults to "text/html".

Certificate Manager configuration

Select the US East (N. Virginia) region, request a certificate for your custom domain with both the wildcard and naked domain - e.g. *.example.org and example.org - and confirm the email request.

API Gateway configuration

1. Create a new API in Amazon API Gateway with the name subdomain-redirect.
2. Select Resources => Actions => Create Method and choose ANY as HTTP method. Enable Use Lambda Proxy integration, choose your lambda region, enter the function name (subdomain-redirect) and save the method.
3. Select Resources => Actions => Create Resource, enable Configure as proxy resource and click on Create Resource. Choose your lambda region, enter the function name (subdomain-redirect) and save the method.
4. Next, deploy the API via Resources => Actions => Deploy API with prod as new stage name.
5. Create a custom domain name. Enter the naked domain (e.g. example.org) if you want to redirect to the www subdomain. Enter the subdomain (e.g. www.example.org) if you want to redirect to the parent domain. Add a base path mapping to the subdomain-redirect API with the Path empty and the stage set to prod and save the custom domain.

Route53 configuration

In Amazon Route 53 in your hosted zone, create a new record for your custom domain. Set the Type to A, Alias to Yes and set the Alias Target to the Target Domain Name from the custom domain setup in API Gateway.

License

Released under the MIT license.

Author

Sebastian Tschan