cloud/aws/upsert.json

{
  "Comment": "$HOST.$DOMAIN:$REC=$VAL",
  "Changes": [
    {
      "Action": "UPSERT",
      "ResourceRecordSet": {
        "Name": "$HOST.$DOMAIN",
        "Type": "$REC",
        "TTL": 60,
        "ResourceRecords": [
          {
            "Value": "$VAL"
          }
        ]
      }
    }
  ]
}