One of the most useful features of AWS is the ability to do pretty much everything from the provided CLI tools. Even more usefully they are actually pretty easy to use! For a number of reasons (including automating deployments, updating records based on dynamic IP addresses and creating internal hostnames for instance deployments) I wanted to be able to push updates to DNS zones hosted on AWS Route53, and I wanted to be able to script the process. Below is an example of how acheive these updates from the CLI (in this instance updating an existing host record). Assumptions: You have installed and configured the AWS cli tools & the credentials you are using have the permissions necessary to make updates. If you need any pointers with this you can find AWS’s documentation here. Step 1 – Get the hosted zone ID When you push a DNS update to Route53 you need to pass in the ID of the hosted zone (a hosted zone normally being the domain name you wish to update). This command will list all of the zones / domains currently hosted under your account: returning an output along the lines of: “Id”: “/hostedzone/Z1W9BXXXXXXXLB” is the bit you’re looking for with everthing after ‘/hostedzone/’ being the ID (in this instance Z1W9BXXXXXXXLB). Step 2 – Building the change file The changes are requested by building out a JSON file which is then sent to AWS. The format of this file varies a little based on the type of record you wish to update (details of this can be found here). In this instance i’m updating the A record homerouter.oliverhelm.me with a new IP address. Create a file (i’ve called it: change-resource-record-sets.json) and insert the below. The action ‘UPSERT’ will update the record for homerouter.cunniffehelm.co.uk if it exists and it not will create it. Hint: Using http://jsonlint.com/ to check the format of your JSON file saves a fair bit of faffing around. Step…