How we saved over $240K per year by replacing Mixpanel with Google BigQuery, Pub/Sub, Dataflow & Kubernetes (code snippet #1)

api.js

"use strict";

require('@google/cloud-trace').start();

const fs = require('fs');
const stream = require('stream');
const PubSub = require('@google-cloud/pubsub');
const util = require("util");
const request = require("request");
const bodyParser = require("body-parser");

const pubsubClient = PubSub({});

const topicPeople = pubsubClient.topic('people');
const topicEvents = pubsubClient.topic('events');

const express = require('express');
const app = express();
app.use(bodyParser.text({type: '*/*'}));
app.use(bodyParser.text({type: '*'}));
app.use(bodyParser.text({type: ''}));

function parse(req, res, topic) {
    let user_ip = req.get("X-Forwarded-For");
    console.log(user_ip);
    if (!user_ip) {
        user_ip = req.connection.remoteAddress;
    }
    else {
        user_ip = user_ip.split(', ')[0];
    }
    let msg = {
        'dataset': req.params.dataset,
        'server_time': new Date().getTime()/1000,
        'ip': user_ip,
        'raw_input': req.body
    };
    topic.publish(msg, (err, messageIds, apiResponse) => {
        if (!!err) {
            res.status(500).send(`${err}\n${apiResponse}`);
        }
        else {
            res.status(200).send('ok');
        }
    });
}

app.get('/', function (req, res) {
    res.send('ok')
});

app.post('/:dataset/events', function (req, res) {
    parse(req, res, topicEvents);
});

app.post('/:dataset/people', function (req, res) {
    parse(req, res, topicPeople);
});

app.listen(5000, function () {
    console.log('App listening!')
});