CloudFlare dynamic dns updater module for Synology

cloudflaredns.sh

#!/bin/sh

# cloudflareddns.sh - dynamic dns updater module for Synology
#
# Author:
#	Michael Wildman (http://mwild.me) [v0.2]
#	Chris Moore [v0.3]
#
# Version:
#	0.3
#
# Description:
#	copy to /sbin/cloudflaredns.sh
#	make executable (chmod +x)
#	add the following entry to /etc.defaults/ddns_provider.conf
#
#		[CloudFlare]                                                                                                                                                
#			modulepath=/sbin/cloudflaredns.sh                                                                                                                   
#			queryurl=https://www.cloudflare.com/api_json.html?a=rec_edit&tkn=__PASSWORD__&email=__USERNAME__&z=__HOSTNAME__&content=__MYIP__ 
#	
#	(note that URL is not actually used, DSM will pass us the variables)
#	run a rec_load_all query to get the record id
#	(see https://www.cloudflare.com/docs/client-api.html)
#
# Changelog:
#	0.2:
#		- Simplified this thing to its most basic requirements (curl + logging)
#		- Now either returns 'good' or the result (no checking for cases -- the log was always more useful anyway!)
#	0.3:
#		- Added __CFBASEURL__
#		- Added code to fetch all zones and find the right one to update
#		- Added code to fetch the record ID and name for the hostname
#		- Changed final __URL__
#
# v0.3 Based on cloudflaredns.sh by Michael Wildman (https://gist.github.com/tehmantra/)
# v0.2 Based on Brian Schmidt Pedersen (http://blog.briped.net) gratisdns.sh

# TODO
# read addition parameters from cloudflare api calls
#
__CFBASEURL__="https://www.cloudflare.com/api_json.html"

# these variables are passed by DSM
# username is your email
__USERNAME__="$(echo ${@} | cut -d' ' -f1)"
# password is your cloudflare API key
__PASSWORD__="$(echo ${@} | cut -d' ' -f2)"
__HOSTNAME__="$(echo ${@} | cut -d' ' -f3)"
__MYIP__="$(echo ${@}  | cut -d' ' -f4)"

# log location
__LOGFILE__="/var/log/cloudflareddns.log"

# additional parameters needed for CloudFlare
__RECTYPE__="A"
__RECID__=""
__RECNAME__=""
__TTL__="1"
__SERVICEMODE__="0"

log() {
	__LOGTIME__=$(date +"%b %e %T")
	if [ "${#}" -lt 1 ]; then
		false
	else
		__LOGMSG__="${1}"
	fi
	if [ "${#}" -lt 2 ]; then
		__LOGPRIO__=7
	else
		__LOGPRIO__=${2}
	fi

	logger -p ${__LOGPRIO__} -t "$(basename ${0})" "${__LOGMSG__}"
	echo "${__LOGTIME__} $(basename ${0}) (${__LOGPRIO__}): ${__LOGMSG__}" >> ${__LOGFILE__}
}

# Fetch all zones available
__URL__="${__CFBASEURL__}?a=zone_load_multi&tkn=${__PASSWORD__}&email=${__USERNAME__}"
__RESPONSE__=$(curl --silent "${__URL__}")

# Parse the response
__REGEX__="\"zone_name\":\"([a-zA-Z0-9]+([-.]?[a-zA-Z0-9]+)*.[a-zA-Z]+)"
__ZONES__=$(echo ${__RESPONSE__} | grep -rosE "${__REGEX__}" | awk -F ':"' '{print $2}')

# Check which zone the __HOSTNAME__ belongs to
for zone in ${__ZONES__}
do
	# Match on either sub-domain or root domain (e.g. if the hostname is the root itself):
	if [ `echo ${__HOSTNAME__} | grep -E "(.*\.${zone//\./\\\.}$|^${zone//\./\\\.}$)"` ]
	then
		 __ZONE__=${zone}
	fi
done

if [ '${__ZONE__}' != '' ]
then
	# Fetch the zone for this hostname and get the record ID
	__URL__="${__CFBASEURL__}?a=rec_load_all&tkn=${__PASSWORD__}&email=${__USERNAME__}&z=${__ZONE__}"
	__RESPONSE__=$(curl --silent "${__URL__}")

	# Parse the response to get the record ID and name
	__REGEX__="\"rec_id\":\"([0-9]*)\",\"rec_hash\":\"[a-z0-9]*\",\"zone_name\":\"${__ZONE__}\",\"name\":\"${__HOSTNAME__}\",\"display_name\":\"[A-z0-9]*"
	__RECID__=$(echo ${__RESPONSE__} | grep -rosE "${__REGEX__}" | awk -F ':"' '{print $2}' | awk -F '"' '{print $1}')
	__RECNAME__=$(echo ${__RESPONSE__} | grep -rosE "${__REGEX__}" | awk -F ':"' '{print $6}')
else
	log "Not sending update, no zone match for: ${__HOSTNAME__}" 7
	__RESULT__="nohost"
fi

if [ '${__RECID__}' != '' ] && [ ${__RECID__} -ge 0 ]
then
	# Send the update to CF API
	__URL__="${__CFBASEURL__}?a=rec_edit&tkn=${__PASSWORD__}&email=${__USERNAME__}&z=${__ZONE__}&type=${__RECTYPE__}&id=${__RECID__}&name=${__RECNAME__}&content=${__MYIP__}&ttl=${__TTL__}&service_mode=${__SERVICEMODE__}"

	# Update DNS record:
	log "Updating with ${__MYIP__}..." 7
	__RESPONSE__=$(curl --silent "${__URL__}")

	# Strip the result element from response json
	__RESULT__=$(echo ${__RESPONSE__} | grep -o -E .result.:.[A-z]+.)
else
	log "Not sending update, no record found for ${__HOSTNAME__} in zone: ${__ZONE__}" 7
	__RESULT__="nohost"
fi

case ${__RESULT__} in
	'"result":"success"')
		__STATUS__='good'
		true
		;;
	*)
		__STATUS__="${__RESULT__}"
		log "__RESPONSE__=${__RESPONSE__}" 5
		false
		;;
esac
log "Status: ${__STATUS__}" 6

printf "%s" "${__STATUS__}"