In-a-Dyn AWS Route53

In-a-Dyn is included as a dynamic dns tool in DD-WRT, Ubiquiti UniFi, and probaly a bunch of others I am not aware of. Though AWS Route53 is not a supported provider, In-a-Dyn provides the ability to specify custom provider.

This repo sets up an AWS API Gateway with a Lambda endpoint that updates a DNS records when it receives GET requests from your router OS running In-a-Dyn. This is usually implemented as an event based trigger which is prefered to periodic polling.

Getting started

1. Configure your stack props in the /bin/dyn-dns.ts file.
2. Deploy

   npm install
   # Deploy the stack
   npm run cdk deploy
   # Destroy the stack
   npm run cdk destroy

3. Configure router by going to the Dynamic DNS settings and select a "custom" service provider and set the following fields.
   • Hostname - Enter to the DNS record you want the service to update with an A record with your WAN IP as the value.
   • Username - Enter authUsernamevalue set in stack props; default is ddnsuser.
   • Password - Enter this value of the API Key that was created (see AWS Console > API Gateway > API Keys).
   • Server - Enter domainName value set in the stack props.

Now you should have a free private DDNS service that works with most routers.

Architecture

"No kill like overkill."

client ---> www ---> API Gateway ---> Lambda Authorizer ---> Lambda Updater ---> Route53

1. API Gateway is a REST API that uses a "REQUEST" authorizer with a default policy cache of 1 hour to prevent abuse, see authCacheTtl. The API Key is attached to a usage plan with very restricted rate limits.
2. Lambda Authorizer is responseble for the basic authentication check against the created API Key and provided authUsername.
3. Lambda Updater is integrated via a "Proxy Integration" and is responsible for validating the request and updating Route53. The incoming hostname is validated against against the allow or block list, and provided eligible zones.