Serverless

The pros and cons of building a company

without infrastructure

Luciano Mammino

loige.link/shift2017

1 June 2017, Split

Who is LUCIANO

lmammino

loige

loige.co

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built with ⚡️serverless

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Agenda

What is Serverless

History & definition

Advantages & costs

How it Works

Example: AWS Lambda

Example: Serverless Framework

Serverless at Planet 9

Architecture

Security

Quality

Monitoring / Logging

Step Functions

PART 1

What is Serverless

1996 - Let's order few more servers for this rack...

2006 - Let's move the infrastructure in "the cloud"...

2013 - I can "ship" the new API to any VPS as a "container"

TODAY - I ain't got no infrastructure, just code "in the cloud" baby!

loige.link/serverless-commitstrip

The essence of the serverless trend is the absence of the server concept during software development.

— Auth0

loige.link/what-is-serverless

Serverless & Serverless.com Framework

👨‍💻 Focus on business logic, not on infrastructure

🐎 Virtually “infinite” auto-scaling

💰 Pay for invocation / processing time

Advantages of serverless

Is it cheaper to go serverless?

... It depends

Car analogy

Cars are parked 95% of the time (loige.link/car-parked-95)

How much do you use the car?

Own a car

(Bare metal servers)

Rent a car

(VPS)

City car-sharing

(Serverless)

loige.link/serverless-calc

Less than $0.40/day

for 1 execution/second

What can we build?

📱 Mobile Backends

🔌 APIs & Microservices

📦 Data Processing pipelines

⚡️ Webhooks

🤖 Bots and integrations

⚙️ IoT Backends

💻 Single page web applications

The paradigm

Event → 𝑓

IF   ________________________________ 

THEN ________________________________

"IF this THEN that" model

A new CSV file is saved in the object storage

Process it and save it in the DB

HTTP request: GET /products

Retrieve products from DB and return a JSON

It's 2 AM

Scrape weather forecast for next days

Cloud providers

IBM

OpenWhisk

AWS

Lambda

Azure

Functions

Google

Cloud Functions

Auth0

Webtask

Serverless and JavaScript

Frontend

🌏 Serverless Web hosting is static, but you can build SPAs
(React, Angular, Vue, etc.)

Backend

👌 Node.js is supported by every provider

⚡️ Fast startup (as opposed to Java)

📦 Use all the modules on NPM

🤓 Support other languages/dialects
(TypeScript, ClojureScript, ESNext...)

exports.myLambda = function (
    event,
    context,
    callback
) {

  // get input from event and context

  // use callback to return output or errors

}

Anatomy of a Node.js lambda on AWS

Let's build a "useful"

Hello World API

// write code here


'use strict'

exports.helloWorldHandler = (event, context, callback) => {
  
  const name = 
   (event.queryStringParameters && event.queryStringParameters.name) ?
    event.queryStringParameters.name : 'Split';
    
  const response = {
    statusCode: 200,
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({message: `Hello ${name}`})
  };

  callback(null, response);
};

🤙

API Gateway config has been generated for us...

Recap

Login to AWS Dashboard
Create new Lambda from blueprint
Configure API Gateway trigger
Configure Lambda and Security
Write Lambda code
Configure Roles & Publish

⚡️Ready!

No local testing 😪 ... Manual process 😫

Enter the...

Get serverless framework

 npm install --global serverless@latest


 sls --help

Create a project

 mkdir helloWorldApi

 cd helloWorldApi

 touch handler.js serverless.yml

// handler.js

'use strict';
exports.helloWorldHandler = (event, context, callback) => {
    const name = 
     (event.queryStringParameters && event.queryStringParameters.name) ?
      event.queryStringParameters.name : 'Split';
    const response = {
      statusCode: 200,
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({message: `Hello ${name}`})
    };
    callback(null, response);
};

# serverless.yml

service: sls-helloWorldApi

provider:
  name: aws
  runtime: "nodejs6.10"

functions:
  helloWorld:
    handler: "handler.helloWorldHandler"
    events:
      - http:
        path: /
        method: get

Local test

touch event.json

{
  "queryStringParameters": {
    "name": "Tim Wagner"
  },
  "httpMethod": "GET",
  "path": "/"
}

Local test

Deploy the lambda

Recap

Install serverless framework
Create handler & serverless config
Test locally (optional)
Deploy
Party hard! 🤘

PART 2

Serverless at Planet 9

https://planet9energy.com

a Big Data company

E.g. Meter readings per customer/year

2 × 24 × 365

Half Hours

× 25

~ meter reading points

× 24

~ data versions

= 💩load™

of data

👩‍🚀 Limited number of “Full stack” engineers

⚡️ Write & deploy quality code fast

👻 Experiment different approaches over different features

😎 Adopt hot and relevant technologies

Limited number of servers = LIMITED CALLS AT 2 AM!

Why Serverless

Current infrastructure

Serverless land

Web

API & Jobs

Messaging

Serverless

Frontend & Backend

Cloufront & S3

API Gateway & Lambda

planet9energy.io

api.planet9energy.io

Access-Control-Allow-Origin: https://planet9energy.io

CORS HTTP HEADER

Custom error page
index.html

Serverless Web Hosting

Serverless APIs

Security: Authentication

"Who is the current user?"

JWT Tokens

Custom
Authorizer Lambda

JWT Token

Authorizer

Login

user: "Podge"
pass: "Unicorns<3"

Users DB

Check
Credentials

JWT token

Validate token & extract userId

API request

API 1

API 2

API 3

Security: Authorization

"Can Podge trade for Account17 ?"

User

Action

Resource

User	Action	Resource
Podge	trade	Account17
Podge	changeSettings	Account17
Luciano	delete	*
...	...	...

Custom ACL module used by every lambda

Built on node-acl & knex.js

Persistence in Postgres

import { can } from '@planet9/acl';

export const tradingHandler =
  async (event, context, callback) => {

  const user = event.requestContext.userId;
  const account = event.pathParameters.accountId;
  const isAuthorized = await can(user, 'trade', account);

  if (!isAuthorized) {
    return callback(new Error('Not Authorized'));
  }

  // ... business logic
}

Security: Sensitive Data

export const handler = (event, context, callback) => {

  const CONN_STRING = process.env.CONN_STRING;

  // ...
}

# serverless.yml

functions:
  myLambda:
    handler: handler.myHandler
    environment:
      CONN_STRING: ${env:CONN_STRING}

Serverless environment variables

Split business logic into small testable modules
Use dependency injection for external resources
(DB, Filesystem, etc.)
Mock stuff with Jest
Aim for 100% coverage
Nyan Cat test runners! 😼

Quality: Unit Tests

Use child_process.exec to launch "sls invoke local"
Make assertions on the JSON output
Test environment simulated with Docker (Postgres, Cassandra, etc.)
Some services are hard to test locally (SNS, SQS, S3)

Quality: Functional Tests

👨 Git-Flow

Feature branches
Push code
GitHub -> CI

Quality: Continuous integration

🤖 CircleCI

Lint code (ESlint)
Unit tests
Build project
Functional tests
if commit on "master": create deployable artifact

Development / Test / Deployment

Debugging

... How do we debug then

console.log... 😑
Using the debug module
Enable detailed logs only when needed
(e.g. export DEBUG=tradingCalculations)

Step Functions

Coordinate components of distributed applications
Orchestrate different AWS Lambdas
Visual flows
Different execution patterns (sequential, branching, parallel)

Some lessons learned...

🚗 Think serverless as ~~microservices~~ "microfunctions"

❄️ Cold starts!

🚫 Be aware of soft limits

🛠 There is still some infrastructure: use proper tools
(Cloudformation, Terraform, ...)

👍 PROs

👍

Agility

👍

Focus on delivering

Business Value

👍

Auto-scalability

👍

Managed service

No calls at 2 am...

👍

Smooth
Learning Curve

👍

Pay as you go!

👎 CONs

👎

No live debugging

👎

Local development & testing

👎

Service/Functions

Orchestration

👎

Servers are still there

👎

lacking

Tooling / Best practices

Should I switch to
SERVERLESS ? 😱

Thanks

loige.link/shift2017

@loige

(special thanks to @katavic_d, @Podgeypoos79, @quasi_modal & @augeva)

Serverless, the pros and cons of building a company without infrastructure - Shift Conference, Split 2017

By Luciano Mammino

Serverless, the pros and cons of building a company without infrastructure - Shift Conference, Split 2017

Planet9energy.com is a new electricity company building a sophisticated analytics and energy trading platform for the UK market. Since the earliest draft of the platform, we took the unconventional decision to go serverless and build the product on top of AWS Lambda and the Serverless framework using Node.js. In this talk, I want to discuss why we took this radical decision, what are the pros and cons of this approach and what are the main issues we faced as a tech team in our design and development experience. We will discuss how normal things like testing and deployment need to be re-thought to work on a serverless fashion but also the benefits of (almost) infinite self-scalability and the piece of mind of not having to manage hundreds of servers. Finally, we will underline how Node.js seems to fit naturally in this scenario and how it makes developing serverless applications extremely convenient.

22,568

Luciano Mammino PRO

Cloud developer, entrepreneur, fighter, butterfly maker! #nodejs #javascript - Author of https://www.nodejsdesignpatterns.com , Founder of https://fullstackbulletin.com

Serverless

The pros and cons of building a company

without infrastructure

Luciano Mammino

Who is LUCIANO

fancy a coupon? 😇

built with ⚡️serverless

Agenda

PART 1

What is Serverless

Serverless & Serverless.com Framework

Advantages of serverless

Is it cheaper to go serverless?

... It depends

Car analogy

What can we build?

The paradigm

"IF this THEN that" model

Cloud providers

Serverless and JavaScript

Anatomy of a Node.js lambda on AWS

Let's build a "useful"

Hello World API

Recap

Enter the...

Get serverless framework

Create a project

Local test

Local test

Deploy the lambda

Recap

PART 2

Serverless at Planet 9

a Big Data company

Why Serverless

Current infrastructure

Serverless

Frontend & Backend

Security: Authentication

Security: Authorization

Security: Sensitive Data

Quality: Unit Tests

Quality: Functional Tests

Quality: Continuous integration

Development / Test / Deployment

Debugging

... How do we debug then

Step Functions

Some lessons learned...

👍 PROs

👎 CONs

Should I switch to SERVERLESS ? 😱

Thanks

Serverless, the pros and cons of building a company without infrastructure - Shift Conference, Split 2017

More from Luciano Mammino

Should I switch to
SERVERLESS ? 😱