cloudfront-set-useragent-for-crawlers

cloudfront-set-useragent-for-crawlers.js

'use strict';
 
exports.handler = (event, context, callback) => {
    const request = event.Records[0].cf.request;
    const headers = request.headers;
    const uri = request['uri'];
    const botPattern = "Googlebot\\/|Googlebot-Mobile|Googlebot-Image|Googlebot-News|Googlebot-Video|AdsBot-Google([^-]|$)|AdsBot-Google-Mobile|Mediapartners-Google|Mediapartners \\(Googlebot\\)|APIs-Google|bingbot";
    var re = new RegExp(botPattern, 'i');
    var userAgent = headers['user-agent'][0]['value'];

    if (re.test(userAgent)) {
        headers['user-agent'] = [{key: 'User-Agent', value: userAgent}];
    } else {
        headers['user-agent'] = [{key: 'User-Agent', value: 'Human'}];
    }

    callback(null, request);
};