Analytics

Simple server (~150 lines of code) for handling analytics data and passing it to Keen.io as a storage.

API heavily inspired by micro-analytics, all credit due.

Introduction

I was looking for a simple solution for counting views or simple events on my personal site. I wanted to keep it simple by setting up following constraints:

zero cookies usage on the site
negligible effect on bundle size of the site
nice UI for browsing events
gather useful information about the users (location, device type) without any way of identyfing them
minimize "sysadmin" work needed to get it up and running (ideally no full blown database to store the events
free / cheap hosting

I discovered Keen.io which covers most of the above needs, is cheap for relatively small traffic (see pricing), is offering great UI for browsing the events and even takes care of things like parsing User Agent strings or getting geo location data from passed IP information.

On the other hand most of the functionality provided by their tracking script (keen-tracking) is not needed for my simple needs thus this tiny server has come to life.

Prerequisites

You will need to setup your own project in Keen.io, to do this, please follow this guide. Once you have your project you will need two types of information in order to launch the server: projectId and writeKey, you can obtain them in your projects access tab (these are the same kind of information that their normal tracking script uses).

Setup

First you will need to clone this repository.

git clone https://github.com/straku/analytics.git

After that install the dependencies

npm install

Run the server locally

KEEN_PROJECT_ID=your_project_id KEEN_WRITE_KEY=your_write_key npm start

Server is up and running on localhost:3000 and every event you send to it will be stored in Keen.io project specified in env variables used in above command.

As the project is using micro and micro-dev you can also use dev mode (check micro-dev docs to see the features of dev mode) locally:

KEEN_PROJECT_ID=your_project_id KEEN_WRITE_KEY=your_write_key npm run dev

You can also allow traffic only from specific origin using AC_ALLOW_ORIGIN env variable. The domain you will provide as a value of this env will be used for `Access-Control-Allow-Origin' response header.

Usage

Server supports two types of requests

GET
POST

GET request is intended for simple views of a specific page, hitting:

localhost:3000/test

Will create view event with following payload:

{
  page: '/test'
}

POST request is not requiring any additional pathname (hit localhost:3000) but needs json body with following shape:

{
  "event": "name_of_the_event",
  "payload": {
    "example_key": "example_value"
  }
}

event field is required, payload is optional

It will create name_of_the_event with following payload:

{
  example_key: 'example_value'
}

Every payload is enriched with following information:

geographical location (based on the IP read from request connection, IP is removed and not pushed to Keen.io), check docs for details
parsed User Agent string data, check docs for details
datetime info, check docs for details

Deployment

I've used now (version 1) to deploy my instance of this server. The instruction is as follows (it assumes you have now installed and are in repository root directory):

now -e KEEN_PROJECT_ID=your_project_id -e KEEN_WRITE_KEY=your_write_key

If you want to learn more about env variables usage in now, check this blog post