update_r53_local.sh

#! /bin/bash
ZONE_NAME=XXXXXXXX.local
HOSTED_ZONE_ID=/hostedzone/XXXXXXXXXXXXXX

FILEBUF=r53_local.json

FLG=0

PRIVATE_ADDRESS_TABLE=$(aws ec2 describe-instances | jq -r '.Reservations[].Instances[]|{InstanceName: (.Tags[]|select(.Key=="Name").Value),PrivateIpAddress}|[.InstanceName, .PrivateIpAddress]|@csv')

echo "" > ${FILEBUF}
echo "{" >> ${FILEBUF}
echo "  \"Comment\": \"update ${ZONE_NAME} from script\"," >> ${FILEBUF}
echo "  \"Changes\": [" >> ${FILEBUF}
echo "${PRIVATE_ADDRESS_TABLE}" | while read line; do
  arrBuf=(${line//,/ });
  HOST_NAME=$(echo "${arrBuf[0]}"|sed -e 's/^"//' -e 's/"$//')
  FQDN=$(echo ${HOST_NAME}|awk '{print tolower($0)}')'.'$ZONE_NAME
  IP_ADDRESS=$(echo "${arrBuf[1]}"|sed -e 's/^"//' -e 's/"$//')
  if [[ ! -z "${IP_ADDRESS}" ]]; then
    if [ ${FLG} -eq 1 ]; then
      echo "  }," >> ${FILEBUF}
    fi
    FLG=1
    cat <<EOT >> ${FILEBUF}
  {
    "Action": "UPSERT",
    "ResourceRecordSet": {
      "Name": "${FQDN}",
      "Type": "A",
      "TTL": 300,
      "ResourceRecords": [
        {
          "Value": "${IP_ADDRESS}"
        }
      ]
    }
EOT
  fi
done
echo "  }" >> ${FILEBUF}
echo "  ]" >> ${FILEBUF}
echo "}" >> ${FILEBUF}

aws route53 change-resource-record-sets --hosted-zone-id ${HOSTED_ZONE_ID} --change-batch file://./${FILEBUF}

rm ${FILEBUF}