ec2-register-dns-route53

Script to create CNAME record pointing to EC2 instance's Public DNS record in Route53

Installation

Create IAM Policy in AWS (edit with your Hosted Zone ID in Route53):

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "route53:ChangeResourceRecordSets",
                "route53:GetHostedZone",
                "route53:ListResourceRecordSets"
            ],
            "Effect": "Allow",
            "Resource": [
                "arn:aws:route53:::hostedzone/<ZoneID>"
            ]
        },
        {
            "Action": [
                "route53:ListHostedZones",
                "route53:ListHostedZonesByName"
            ],
            "Effect": "Allow",
            "Resource": [
                "*"
            ]
        }

Create new user in IAM along with an access key, then attach the policy from above to the new user account.

Next install cli53 from https://github.com/barnybug/cli53.

Next create a directory where you will keep the config and shell script files (/etc/route53). Edit the config file with your relevant information, and chmod it with 600, and chmod the shell script with 700.

Now test running the script and you should see it create a CNAME record in Route53.

Now create an entry in your crontab with @reboot to run the script when the system boots.

@reboot /etc/route53/register-route53.sh >> /root/register-route53.log 2>&1

Now shutdown the server (not reboot) and start it back up, when the server boots back up it will pickup a new dynamic public IP address (unless your using an Elastic IP) and the cron job will update the CNAME record in Route53 with the new Public IP/DNS entry.

More Info

Blog post on my site for more information.