Simple shellscript to update Route 53 record with the current public IP

update_route_53.sh

#!/bin/bash
# Use EC2 Role to allow the EC2 modify Route 53 record, instead of AWS_SECRET_KEYS

AWS_REGION="us-east-1"
HOSTED_ZONE_ID="XXXXXXXXXXXXXXXXXXXX"
DOMAIN_NAME="example.com"

# Get the current IP address
EC2_IP=$(curl http://169.254.169.254/latest/meta-data/public-ipv4)


JSON_DATA=$(cat <<EOF
{
  "Comment": "Update IP address",
  "Changes": [
    {
      "Action": "UPSERT",
      "ResourceRecordSet": {
        "Name": "${DOMAIN_NAME}",
        "Type": "A",
        "TTL": 300,
        "ResourceRecords": [
          {
            "Value": "${EC2_IP}"
          }
        ]
      }
    }
  ]
}
EOF
)

# Update the DNS record
RESPONSE=$(/usr/local/bin/aws route53 change-resource-record-sets \
  --hosted-zone-id $HOSTED_ZONE_ID \
  --change-batch "$JSON_DATA" \
    --query "ChangeInfo.Id" \
    --output text \
    --region $AWS_REGION)

echo $RESPONSE