dnsimplle

#!/bin/bash

HOSTNAME=$(curl -s http://metadata/computeMetadata/v1beta1/instance/hostname | cut -d '.' -f 1)
APIKEY=$(curl -s http://metadata/computeMetadata/v1beta1/project/attributes/dnsimpleDomainToken)
DOMAIN=$(curl -s http://metadata/computeMetadata/v1beta1/project/attributes/dnsimpleDomain)
IP=$(curl -s http://metadata/computeMetadata/v1beta1/instance/network-interfaces/0/access-configs/0/external-ip)

if [ $(curl -s -X GET -H "X-DNSimple-Domain-Token: $APIKEY" -H "Accept: application/json" "https://dnsimple.com/domains/$DOMAIN/records?type=A" | grep $HOSTNAME | wc -l) -eq 0 ]; then
        echo "Creating new record..."
        curl -s -X POST -H "X-DNSimple-Domain-Token: $APIKEY" -H "Accept: application/json" -H "Content-Type: application/json" -d "{\"record\":{\"name\":\"$HOSTNAME\",\"record_type\": \"A\", \"content\": \"$IP\", \"ttl\": 60}}" "https://dnsimple.com/domains/$DOMAIN/records"

else
        ID=$(curl -s -X GET -H "X-DNSimple-Domain-Token: $APIKEY" -H "Accept: application/json" "https://dnsimple.com/domains/$DOMAIN/records?type=A" | python -mjson.tool | grep "\"$HOSTNAME\"" -B4 -A6 | grep '"id"' | grep -Eo '[0-9]+')
        echo "Found existing record with ID $ID"
        curl -s -X PUT -H "X-DNSimple-Domain-Token: $APIKEY" -H "Accept: application/json" -H "Content-Type: application/json" -d "{\"record\":{\"name\":\"$HOSTNAME\",\"record_type\": \"A\", \"content\": \"$IP\", \"ttl\": 60}}" "https://dnsimple.com/domains/$DOMAIN/records/$ID"
fi