Notes on Kevin Whinnery's Workshop: Complete Node.js - From Zero to Production

0. Setup and Running Locally

Links

• TodoMVC++ Github Repo: TodoMVC++ is the companion application for Zero to Production with Node.
• The Elastic Beanstalk Command Line Interface (EB CLI): Command line interface for Elastic Beanstalk.
• ngrok: Secure tunnels to localhost.
• Locust: An open source load testing tool.
• Rollbar: Error tracking Service for the Server side.
• TrackJS: Error tracking on the Client side.
• Google Analytics
• universal-analytics: A node module for Google's Universal Analytics tracking.

Installing Node modules

❯ npm install

Installing and Starting Postgres

On a Mac, the easiest path to installing Postgres is Homebrew:

❯ brew update
❯ brew install postgresql

Start Postgres:

❯ pg_ctl -D /usr/local/var/postgres start

Setting up the databases

Create the databases for the project and apply the migrations:

❯ createdb todos
❯ createdb todos-test
❯ npm run migrate

(Optional) Using ElephantSQL rather than a local Postgres DB

If Postgres is not installed locally, you can setup a free instance as follows:

1. Visit ElephantSQL.
2. Login and setup a free tiny turtle instance.
3. Goto Details and copy the Postgres url.

Create a config/user.js file and change the value of config.database accordingly:

'use strict'

let config = {}
config.databaseUrl = 'postgres://whatever:fromElephantSQLWeb'

module.exports = config

Migrate the database:

❯ npm run migrate

Running the application in development mode

❯ NODE_ENV=development
❯ npm run grunt collect_static
❯ npm run grunt

Running the application simulating production settings

❯ NODE_ENV=production
❯ npm run grunt collect_static
❯ npm start

1. The express web server

The most basic express server with middleware

index.js

const express = require('express')
const createUserMiddleware = require('./middleware')
const app = express()

app.use(createUserMiddleware('Dave'))

app.get('/hal', (req, res) =>
  res.send(`Just what do you think you are doing, ${req.user.name}?`)
)

app.listen(4000)

middleware.js

const createUser = username =>
  (req, res, next) => {
    req.user = { name: username }
    next()
  }

module.exports = createUser

Run it, Hit it, Get it

1. Run it with ❯ node index.js.
2. Hit it at http://localhost:4000/hal.
3. Get Just what do you think you are doing, Dave?.

2. Production Environment

Lingo

EB -> Elastic BeanStalk. RDS -> Relational Database Service.

Deploy a Node App on AWS

One possible pipeline to get a Node App deployed on AWS using:

• EB:
  • Elastic Load Balancer.
  • EB Environment.
  • Provisions EC2 instances within an AutoScaled Group.
• RDS database on the backend.

Provisioning an EB Environment

1. Select an AWS Region.
2. Create a user with sufficient permissions.
3. Create an EB environment (will be added to a security group).

• Fully functional execution environment for your App.
• Typically you'll have multiple environments:
  • Development
  • Staging
  • Production

4. Create an RDS instance (add to same EB security group).

• Our EB environment instances can connect to our RDS instance.
• The outside world can't directly connect to out RDS instance.

5. Configure security group to allow incoming connections to Postgres.
6. Deploy application version.

The Elastic Beanstalk Command Line Interface (EB CLI)

❯ brew install aws-elasticbeanstalk

eb workflow

❯ eb init
❯ eb create
❯ eb deploy

Where to store the DB Connection String?

• If you configure your RDS instance to NOT accept traffic from the outside, then it's not the end of the world to have the DB Connection String as an Environment Variable (accessible through the console UI).
• But there's an ever better way to store secure credentials in a S3 bucket (in an XML or JSON file) and then load them into the system environment (not accessible through the console UI).

3. Preparing our Application for production

Installing Locust

Install libevent (dependency for gevent):

❯ brew install libevent

Install locust:

❯ pip install locustio

Configuring Locust

Locust opens a new file per new simutaled user, when testing.

• 1000 opened files means 1000 concurrent users.

Raise the number of open files to 1000, in the context of the current terminal session:

❯ ulimit -n 1000

Installing Rollbar

❯ npm install --save rollbar

Basic Rollbar Configuration

const express = require('express')
// Basic Rollbar Usage
const rollbar = require('rollbar')

let app = express()

// Rollback Middleware
app.use(rollbar.errorHandler('TYPE-YOUR-KEY-HERE'))

// Export Express webapp instance
module.exports = app