CloudFlare Dynamic DNS Shell Script

cloudflare_dyn_dns.sh

##!/usr/bin/env sh
# Gist: https://gist.github.com/D0zingcat/8cd76dc49d28c99af010c67a4a94d30b
# forked from: https://gist.github.com/chappy84/9606755
# use environment variables instead of flags (as in docker pass parameters is not very convenient)
# a docker image is derived from this script: d0zingcat/ddns-reporter (:latest tag for amd x86-64 arch and :armv8 tag for arm x64 v8 arch, e.g. raspberry pi 4B
# you could use this image to report your dynamic public ip to cloudflare(to update your A DNS record)
# command: docker run -e KEY=${KEY} -e NAME=${subdomain} -e EMAIL=${cloudflare_email} -e ZONE={base_domain} d0zingcat/ddns-reporter:latest
# Dockerfile: https://github.com/D0zingcat/all-in-docker/blob/main/ddns-reporter/Dockerfile
# CloudFlare Dynamic DNS
#
# Updates CloudFlare records with the current public IP address
#
# Takes the same basic arguments as A/CNAME updates in the CloudFlare v4 API
# https://www.cloudflare.com/docs/client-api.html#s5.2
#
# Use with cron jobs etc.
#
# e.g.
#
# manually run:
# cloudflare_dyn_dns.sh -key 404613183ab3971a2118ae5bf03d63e032f9e -email [email protected] -zone example.com -name extra
#
# cronjob entry to run every 5 minutes:
# */5 * * * * /path/to/cloudflare_dyn_dns.sh -key 404613183ab3971a2118ae5bf03d63e032f9e -email [email protected] -zone example.com -name extra >> /path/to/cloudflare_dyn_dns.log
#
# will both set the type A DNS record for extra.example.com to the current public IP address for user [email protected] with theprovided API key
#set -x

key=${KEY}
email=${EMAIL}
zone=${ZONE}
zone_id=${ZONE_ID}
type=A
rec_id=${REC_ID}
name=${NAME}
content=${CONTENT}
ttl=1
proxied=false
report_interval=${REPORT_INTERVAL:-60}

function report() {	
	if [ "$content" = "" ]
	then
	    content=`curl -s -4 http://icanhazip.com/`
	    if [ "$content" = "" ]
	    then
	        date
	        echo "No IP address to set record value with."
	        exit 1
	    fi
	fi
	
	if [ "$name" = "" ]
	then
	    echo "You must provide the name of the record you wish to change."
	    exit 1
	fi
	
	if [ "$zone" = "" ]
	then
	    echo "You must provide the domain you wish to change."
	    exit 1
	fi
	
	if [ "$name" = "$zone" ]
	then
	    hostname="$name"
	else
	    hostname="$name.$zone"
	fi
	
	command -v host > /dev/null 2>&1
	if [ "$?" = "1" ]
	then
	    command -v nslookup > /dev/null 2>&1
	    if [ "$?" = "1" ]
	    then
	        echo "Cannot find a way to check existing $type record for $hostname"
	        exit 1
	    fi
	    existing_content=`nslookup -type=$type $hostname | awk -F 'Address: ' 'NR==6 { print $2 }'`
	else
	    existing_content=`host -t $type $hostname | sed -E 's/.+?\s+([^\s]+)$/\1/'`
	fi
	
	if [ "$content" = "$existing_content" ]
	then
	    echo "Existing record value $existing_content is the same as provided content $content. Skip."
	    continue
	fi
	
	if [ "$key" = "" ]
	then
	    echo "You must provide your user API token."
	    exit 1
	fi
	
	if [ "$email" = "" ]
	then
	    echo "You must provide your user email."
	    exit 1
	fi
	
	# Get the zone id for the entry we're trying to change if it's not provided
	if [ "$zone_id" = "" ]
	then
	    zone_response_json=`curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$zone" -H "X-Auth-Email: $email" -H "X-Auth-Key: $key" -H "Content-Type: application/json"`
	    zone_id=`echo $zone_response_json | sed -E "s/.+\"result\":\[\{\"id\":\"([a-f0-9]+)\"[^\}]+$zone.+/\1/g"`
	    if [ "$zone_id" = "" ]
	    then
	        echo "Cloudflare DNS Zone id could not be found, please make sure it exists"
	        exit 1
	    fi
	fi
	
	# Get the record id for the entry we're trying to change if it's not provided
	if [ "$rec_id" = "" ]
	then
	    rec_response_json=`curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_id/dns_records?name=$hostname" -H "X-Auth-Email: $email" -H "X-Auth-Key: $key" -H "Content-Type: application/json"`
	    rec_id=`echo $rec_response_json | sed -E "s/.+\"result\":\[\{\"id\":\"([a-f0-9]+)\"[^\}]+\$hostname\",\"type\":\"$type\"[^\}]+.+/\1/g"`
	    if [ "$rec_id" = "" ]
	    then
	        echo "Cloudflare DNS Record id could not be found, please make sure it exists"
	        exit 1
	    fi
	fi
	
	## Update the DNS record
	update_response=`curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zone_id/dns_records/$rec_id" -H "X-Auth-Email: $email" -H "X-Auth-Key: $key" -H "Content-Type: application/json" --data "{\"id\":\"$rec_id\",\"type\":\"$type\",\"name\":\"$hostname\",\"content\":\"$content\",\"ttl\":$ttl,\"proxied\":$proxied}"`
	
	success_val=`echo $update_response | sed -E "s/.+\"success\":(true|false).+/\1/g"`
	if [ "$success_val" = "true" ]
	then
	    echo "Record Updated."
	else
	    echo "Record update failed."
	    exit 1
	fi 
}


while [ "$1" != "" ]; do
    case $1 in
        -key )     shift
                   key=$1
                   ;;
        -email )   shift
                   email=$1
                   ;;
        -zone )    shift
                   zone=$1
                   ;;
        -zone_id ) shift
                   zone_id=$1
                   ;;
        -type )    shift
                   type=$1
                   ;;
        -rec_id )  shift
                   rec_id=$1
                   ;;
        -name )    shift
                   name=$1
                   ;;
        -content ) shift
                   content=$1
                   ;;
        -ttl )     shift
                   ttl=$1
                   ;;
        -proxied ) shift
                   proxied=$1
                   ;;
        * )        echo "unknown parameter $1"
                   exit 1
    esac
    shift
done

while true;
do
	echo "sleep for $report_interval s"
	sleep $report_interval
	report
done