cloudflare_ddns

#!/bin/sh

CONFIG=$(dirname $0)/.cloudflare

if [ -r $CONFIG ]; then
	. $CONFIG
else
	( >&2 echo "Missing or unreadable $CONFIG" )
fi

# script settings
LOGFILE=$(basename $0).log
THROTTLE_SECONDS=300  # terminate prematurely if run too often
CLOUDFLARE_AUTH_HEADERS="X-Auth-Email: $CLOUDFLARE_EMAIL
X-Auth-Key: $CLOUDFLARE_API_KEY"

# cloudflare prefers token-based auth, so use that if available
if [ -n $CLOUDFLARE_API_TOKEN ]; then
	CLOUDFLARE_AUTH_HEADERS="Authorization: Bearer $CLOUDFLARE_API_TOKEN"
fi

# user input IP address
NEW_IP=$1

log_output()
{
	timestamp=$(date +"%Y-%m-%d %H:%M:%S")
	echo "$timestamp	$1	$2"
} >> $LOGFILE

list_dns_records()
{
	curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$DNS_ZONE_ID/dns_records" \
		-H @- <<- HEADERS
			$CLOUDFLARE_AUTH_HEADERS
		HEADERS
}

list_dns_records_onsuccess()
{
	log_output LIST_SUCCESS "$1"
}

list_dns_records_onfailure()
{
	log_output LIST_FAILED "$1"
}

list_dns_records_onthrottled()
{
	log_output LIST_THROTTLED
}

update_record()
{
	curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$DNS_ZONE_ID/dns_records/$DNS_RECORD_ID" \
		--data "{\"type\":\"$DNS_RECORD_TYPE\",\"name\":\"$DNS_RECORD_NAME\",\"content\":\"$NEW_IP\",\"ttl\":1,\"proxied\":$DNS_RECORD_PROXIED}" \
		-H @- <<- HEADERS
			$CLOUDFLARE_AUTH_HEADERS
			Content-Type: application/json
		HEADERS
}

update_record_onsuccess()
{
	/sbin/ddns_custom_updated 1
	log_output UPDATE_SUCCESS "$1"
} 

update_record_onfailure()
{
	/sbin/ddns_custom_updated 0
	log_output UPDATE_FAILED "$1"
}

update_record_onthrottled()
{
	/sbin/ddns_custom_updated 0
	log_output UPDATE_THROTTLED
}

throttle()
{
	# if we can't read the log file, assume it's a first run
	if [ ! -r $LOGFILE ]; then
		return
	fi

	last_run_time=$(date -d "$(sort -r $LOGFILE | \
		grep '^[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9] [0-9][0-9]:[0-9][0-9]' | \
		grep -vm1 THROTTLED | cut -f 1)" +%s)
	current_time=$(date +%s)
	if [ $(expr $last_run_time + $THROTTLE_SECONDS) -gt $current_time ]; then
		$throttled
		exit 1
	fi
}

command=update_record
success=update_record_onsuccess
failure=update_record_onfailure
throttled=update_record_onthrottled

# if argument is the word 'list', query for a listing of all zone records
if [ "$NEW_IP" = "list" ]; then
	command=list_dns_records
	success=list_dns_records_onsuccess
	failure=list_dns_records_onfailure
	throttled=list_dns_records_onthrottled
fi

throttle

OUTPUT=$($command)

if echo $OUTPUT | grep -q '"success"\s*:\s*true'; then
	$success "$OUTPUT"
else
	$failure "$OUTPUT"
fi