AWS Route 53 Dynamic DNS

Introduction

This app provides a way to keep a consistant url for a network where the external ip address may change from time to time, by adding a record to a domain where the primary DNS is hosted by the Amazon Route 53 service.

There are many reasons why you would want this, the most common is to provide a URL to a service hosted on a domestic network where the ISP is not providing a static ip address, e.g. webserver, vpn to home, etc.. There are other DDNS services out there that may give you a free option, I just want to use my own domain.

This is not is a publicly facing DDNS API, for that I would recomend another repository with a similar name: aws-ddns. This is an application that provides DDNS using the R53 API, it is intended that you run this on one a computer within your network at a frequency that you are happy with.

Pre-Requisites

• An AWS account, this tool uses the Amazon Route 53 service which is part of AWS, so you need an account
• Your own domain, the Route 53 service allows you to manage the DNS of your own domain and this tool allows you to map a subdomain to your current external IP address
• AWS credentials permissioned to modify R53 records stored in a local credentials file located at $HOME/.aws/credentials as you would for the AWS CLI. You can also use the AWS_SHARED_CREDENTIALS_FILE environment variable to locate your credential file, or use AWS_ACCESS_KEY / AWS_SECRET_ACCESS_KEY environment variables to specify your credentials.

How it works

The application works gets it’s external network address over https from some of the many services that are available online. The application has a number of these sites set up as default, but you can choose your own by providing a comma separated list of sites using the -i parameter. Many of these service have limits to the frequency that you can call them, so r532-ddns limits each run to check a random two services out of the services available. The value returned for the ip address is compared to the value that is stored in the Amazon Route 53 DNS settings, and if they differ, the DNS record is updated in Route 53.