Azure function to update IP on Cloudflare DNS; Usefull for DSM DDNS updates.

index.js

// URL set in Synology would look something like this:
// https://<YOUR_SUB_DOMAIN>.azurewebsites.net/api/HttpTriggerJS1?hostname=__HOSTNAME__&ip=__MYIP__&zoneid=__USERNAME__&key=__PASSWORD__&email=<YOUR_CF_EMAIL_LOGIN>&dnsidentifier=<YOUR_DNS_ID_FROM_CF>&recordtype=A

module.exports = function (context, req) {
    context.log('JavaScript HTTP trigger function processed a request.');
    var http = require('https');

    var hostname = req.query.hostname;
    var ip = req.query.ip;
    var zoneid = req.query.zoneid;
    var key = req.query.key;
    var email= req.query.email;
    var dnsIdentifier = req.query.dnsidentifier;
    var recordType = req.query.recordtype;

    var bodyString = JSON.stringify({
        type: recordType,
        name: hostname,
        content: ip,
        proxied: true
    });

    var headers = {
        'Content-Type': 'application/json',
        'X-Auth-Email': email,
        'X-Auth-Key': key,
        'method': 'PUT'
    };

    var options = {
        host: 'api.cloudflare.com',
        path: '/client/v4/zones/'+ zoneid +'/dns_records/' + dnsIdentifier,
        method: 'PUT',
        headers: headers
    };
    var callback = function (response) {
        var str = '';

        //another chunk of data has been recieved, so append it to `str`
        response.on('data', function (chunk) {
            str += chunk;
        });

        //the whole response has been recieved, so we just print it out here
        response.on('end', function () {
            context.log(str);
            context.res = {
                status: 200, /* Defaults to 200 */
                body: "success"
            };
            context.done();
        });
    };

    var r = http.request(options, callback);
    r.write(bodyString);
    r.end();
};