LambdaPing.nodejs

exports.handler = function(event, context, callback) {
    var Ping_domain = (event.domain === undefined ? 'example.com' : event.domain);
    var Ping_protocol = (event.protocol === undefined ? 'https' : event.protocol);
    var Ping_port = (event.port === undefined ? 443 : event.port);
    var Ping_path = (event.path === undefined ? '/' : event.path);
    var Ping_method = (event.method === undefined ? 'GET' : event.method);
    var Ping_success = 0;
    var Ping_responsetime = 0;
    
    const http = require(Ping_protocol);
    
    var options = {
        hostname: Ping_domain,
        port: Ping_port,
        path: Ping_path,
        method: Ping_method
    };

    var start = new Date();
    var req = http.request(options, function(res) {
        Ping_responsetime = (new Date() - start); 
        if (res.statusCode < '400') { Ping_success = 1 } else { Ping_success = 0 } 
        console.log('statusCode:', res.statusCode);
        console.log('Request took:', Ping_responsetime.toFixed(1), 'ms');
        console.log('Request success:', Ping_success.toFixed(1));
        console.log('Region:', process.env.AWS_DEFAULT_REGION);
        
        putCloudWatch(Ping_domain,Ping_success,Ping_responsetime, callback);
    });
    
    req.setTimeout(20000);

    req.end();

    req.on('error', function(e) {
        putCloudWatch(Ping_domain,0,'', callback);
    });
};

function putCloudWatch(Domain, Success, ResponseTime, callback){
    var AWS = require('aws-sdk');
    AWS.config.region = process.env.AWS_DEFAULT_REGION;
    var cloudwatch = new AWS.CloudWatch();
    
    var params = {
            MetricData: [
                {
                    MetricName: 'Available', /* required */
                    Dimensions: [
                        {
                            Name: 'Destination', /* required */
                            Value: Domain /* required */
                        },
                    ],
                    Timestamp: + Math.floor(new Date() / 1000),
                    Unit: 'Count',
                    Value: + Success.toFixed(1) 
                },
                {
                    MetricName: 'Response Time', /* required */
                    Dimensions: [
                        {
                            Name: 'Destination', /* required */
                            Value: Domain + "_" + process.env.AWS_DEFAULT_REGION /* required */
                        },
                    ],
                    Timestamp: + Math.floor(new Date() / 1000),
                    Unit: 'Milliseconds',
                    Value: + ResponseTime.toFixed(1)
                }
            ],
            Namespace: 'LambdaPing' /* required */
        };
        
        cloudwatch.putMetricData(params, function(err, data) {
            if (err) { 
                console.log(err, err.stack);
                callback("Ping Failed");
            } else {
                console.log(data);
                callback(null, "Ping data delivered");
            }
        });
}