Dyndns replacement using Cloudflare, run `npm install`, then `node update-cloudflare.js`

package.json

{
  "name": "dynamic-ip",
  "version": "0.0.1",
  "description": "A tool to update cloudflare with my dynamic IP",
  "main": "update.js",
  "dependencies": {
    "fn.js": "~0.7.0",
    "sequence": "~3.0.0",
    "restler": "~3.2.2"
  },
  "devDependencies": {},
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Wouter Danes",
  "license": "Apache v2.0"
}

update-cloudflare.js

var http = require('http');
var https = require('https');
var querystring = require('querystring');
var fn = require('fn.js');
var Sequence = require('sequence').Sequence;
var rest = require('restler');

var cloudFlareConfig = {
	tkn : '[cloudflare api key]',
	email : '[cloudflare email account]',
	domain : '[domain]',
	targetName : '[host in domain to update]',
	apiUrl : 'https://www.cloudflare.com/api_json.html'
};

function obtainPublicIp(next, hostname) {
	rest
		.get('http://ip4.telize.com/')
		.on('complete', function(ip) {
			console.log('Current IP: ' + ip.trim());
			next(ip.trim(), hostname);
		});
};

function obtainHostInfo(next, wanIp, hostname) {
	var query = {
		tkn : cloudFlareConfig.tkn,
		email : cloudFlareConfig.email,
		z : cloudFlareConfig.domain,
		a : 'rec_load_all'
	};

	rest
		.get(cloudFlareConfig.apiUrl, { query : query })
		.on('complete', function (data) {
			console.log('Looking for record for ' + hostname);
			var infos = fn.filter( function ( info ) {
				return hostname == info.display_name;
			}, data.response.recs.objs);

			console.log('found host info... IP in cloudflare: ' + infos[0].content);

			next(wanIp, infos[0]);
		});
};

function checkIpHasChanged(next, wanIp, hostInfo) {

	if (wanIp == hostInfo.content) {
		console.log("IP has not changed");
		return;
	} else {
		console.log('IP Has changed, old = ' + hostInfo.content + ', new = ' + wanIp);
		next(wanIp, hostInfo);
	}

}

function setNewWanIp(next, wanIp, hostInfo) {
	console.error("Setting New WAN IP: " + wanIp);

	var query = {
		tkn : cloudFlareConfig.tkn,
		email : cloudFlareConfig.email,
		z : cloudFlareConfig.domain,
		a : 'rec_edit',
		type : 'A',
		id : hostInfo.rec_id,
		name : hostInfo.display_name,
		content : wanIp,
		ttl : '1',
		service_mode : '0'
	};

	rest
		.get(cloudFlareConfig.apiUrl, { query : query })
		.on('complete', function (data) {
			console.error(data);
		});

	next();
}

var sequence = Sequence.create();

sequence
	.then(function (next) {
		next(cloudFlareConfig.targetName)
	})
	.then(obtainPublicIp)
	.then(obtainHostInfo)
	.then(checkIpHasChanged)
	.then(setNewWanIp);

Dyndns replacement using Cloudflare, run npm install, then node update-cloudflare.js.
Change the cloudFlareConfig object at the top of the update-cloudflare.js file with your cloudflare details.