A script to update DNS on Route 53

update-route53-dns.sh

#!/bin/sh

# Make sure only root can run our script                
if [ "$(id -u)" != "0" ]; then
    echo "This script must be run as root" 1>&2
    exit 1
fi

# Load configuration
. /etc/route53/config

# Export access key ID and secret for cli53
export AWS_ACCESS_KEY_ID
export AWS_SECRET_ACCESS_KEY

# Use command line scripts to get instance ID and public hostname
INSTANCE_ID=$(ec2metadata --instance-id)
PUBLIC_IP=$(ec2metadata --public-ip)

# Replace the A Zone (because initially created as a A record from template – throws an exception otherwise)
cli53 rrcreate "$ZONE" "$INSTANCE_ID" A "$PUBLIC_IP" --replace --ttl "$TTL"