quick and dirty dns registration of cf stack with route53

registerPrivateIpForCloudFormationStack.sh

#! /bin/bash
# call ./registerPrivateIpForCloudFormationStack.sh domainName stackName hostedZoneName
# requires aws-cli and jq installed, you may want to

function hostedzoneId() {
  export hostedzone
  hostedzone=$(aws route53 list-hosted-zones | jq --raw-output '.HostedZones[] | select(.Name == "$1").Id')
  echo "$hostedzone"
}

function instanceIpsForStack() {
  export ips
  ips=$(aws ec2 describe-instances --filters "Name=instance-state-name,Values=running" "Name=tag:aws:cloudformation:stack-name,Values=$1" | jq --raw-output '.Reservations[].Instances[0].PrivateIpAddress')
  echo "$ips"
}

export json
json='
{
  "HostedZoneId":"",
  "ChangeBatch": {
      "Comment": "Update record to reflect new IP address for a system ",
      "Changes": [
        {
            "Action": "UPSERT",
            "ResourceRecordSet": {
                "Name": "tobereplacedwithparam",
                "Type": "A",
                "TTL": 10,
                "ResourceRecords": [
                ]
            }
        }
    ]
  }
}'

json=$(echo "$json" | jq ".HostedZoneId = \"$(inbotiohostedzone $3)\"")

json=$(echo "$json" | jq ".ChangeBatch.Changes[0].ResourceRecordSet.Name = \"$1\"")

for ip in $(instanceIpsForStack $2); do
  json=$(echo "$json" | jq ".ChangeBatch.Changes[0].ResourceRecordSet.ResourceRecords |= . + [{\"Value\":\"$ip\"}]")
done


#echo "$(echo $json | jq '')"

aws route53 change-resource-record-sets --cli-input-json "$json"