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.

1. BUILDING A SERVERLESS COMPANY WITH
NODE, REACT AND THE SERVERLESS
FRAMEWORK
MAY 10TH 2017, Verona
Luciano Mammino
loige.link/jsday2017
1

2. Who is
LUCIANO
lmammino
loige
loige.co
2

3. NeBK20JV
-20% eBook
NpBK15JV
-15% Print
loige.link/node-book
fancy a coupon? 😇
3

4. fullstackbulletin.com
built with
⚡serverless
4

5. Agenda
What is Serverless
History & definition
Advantages & costs
How it Works
Example on AWS Lambda
Example with Serverless
Framework
Serverless at Planet 9
Architecture
Security
Quality
Monitoring / Logging
Step Functions
5

6. PART 1
What is Serverless
6

7. 1996 - Let's order few more servers for this rack...
7

8. 2006 - Let's move the infrastructure in "the cloud"...
8

9. 2013 - I can "ship" the new API to any VPS as a "container"
9

10. TODAY - I ain't got no infrastructure, just code "in the cloud" baby!
10

11. loige.link/serverless-commitstrip
11

12. “ The essence of the serverless trend is the absence
of the server concept during software development.
— Auth0
loige.link/what-is-serverless
12

13. Serverless & FrameworkServerless.com
13

14. 👨💻👨💻 Focus on business logic, not on infrastructure
🐎🐎 Virtually “infinite” auto-scaling
💰💰 Pay for invocation / processing time (cheap!)
Advantages of serverless
14

15. Is it cheaper to go serverless?
... It depends
15

16. Car analogy
Cars are parked 95% of the time ( )
How much do you use the car?
loige.link/car-parked-95
Own a car
(Bare metal servers)
Rent a car
(VPS)
City car-sharing
(Serverless)
16

17. loige.link/serverless-calc
Less than $0.40/day
for 1 execution/second
17

18. What can we build?
📱 Mobile Backends
🔌 APIs & Microservices
📦 Data Processing pipelines
⚡ Webhooks
🤖 Bots and integrations
⚙ IoT Backends
💻 Single page web applications
18

19. The paradigm
Event → 𝑓
19

20. IF ________________________________
THEN ________________________________
"IF this THEN that" model
20

21. Cloud providers
IBM
OpenWhisk
AWS
Lambda
Azure
Functions
Google
Cloud
Functions
Auth0
Webtask
21

22. 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...)
22

23. 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
23

24. Let's build a "useful"
Hello World API
24

25. 25

26. 26

27. 27

28. 28

29. 29

30. 30

31. 31

32. API Gateway config has been generated for us...
32

33. 33

34. Recap
1. Login to AWS Dashboard
2. Create new Lambda from blueprint
3. Configure API Gateway trigger
4. Configure Lambda and Security
5. Write Lambda code
6. Configure Roles & Publish
⚡Ready!
No local testing 😪 ... Manual process 😫
34

35. Enter the...
35

36. Get serverless framework
npm install --global serverless@latest
sls --help
36

37. Create a project
mkdir helloWorldApi
cd helloWorldApi
touch handler.js serverless.yml
37

38. // handler.js
'use strict';
exports.helloWorldHandler = (event, context, callback) => {
const name =
(event.queryStringParameters && event.queryStringParameters.name) ?
event.queryStringParameters.name : 'Verona';
const response = {
statusCode: 200,
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({message: `Hello ${name}`})
};
callback(null, response);
};
38

39. # serverless.yml
service: sls-helloWorldApi
provider:
name: aws
runtime: "nodejs6.10"
functions:
helloWorld:
handler: "handler.helloWorldHandler"
events:
- http:
path: /
method: get
39

40. Local test
touch event.json
{
"queryStringParameters": {
"name": "Tim Wagner"
},
"httpMethod": "GET",
"path": "/"
}
40

41. Local test
41

42. Deploy the lambda
42

43. Recap
1. Install serverless framework
2. Create handler & serverless config
3. Test locally (optional)
4. Deploy
5. Party hard! 🤘
43

44. PART 2
Serverless at Planet 9
44

45. https://planet9energy.com
45

46. 46

47. 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
47

48. 👩🚀 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
48

49. Current infrastructure
Serverless land
Web API & Jobs Messaging
49

50. 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
50

51. Security: Authentication
"Who is the current user?"
JWT Tokens
Custom
Authorizer Lambda
51

52. JWT Token
Authorizer
Login
user: "Podge"
pass: "Unicorns<3"
Users DB
Check
Credentials
JWT token
Validate token
& extract userId
API request
52
API 1
API 2
API 3

53. Security: Authorization
"Can Podge trade for Account17 ?"
User Action Resource
53

54. User Action Resource
Podge trade Account17
Podge changeSettings Account17
Luciano delete *
... ... ...
Custom ACL module used by every lambda
Built on &
Persistence in Postgres
node-acl knex.js
54

55. 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
}
55

56. Security: Sensitive Data
export const handler = (event, context, callback) => {
const CONN_STRING = process.env.CONN_STRING;
// ...
}
56

57. # serverless.yml
functions:
myLambda:
handler: handler.myHandler
environment:
CONN_STRING: ${env:CONN_STRING}
Serverless environment variables
57

58. 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
58

59. 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
59

60. 👨👨 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
60

61. Development / Test / Deployment
61

62. Debugging
62

63. ... How do we debug then
console.log... 😑
Using the module
Enable detailed logs only when needed
(e.g. export DEBUG=tradingCalculations)
debug
63

64. Step Functions
Coordinate components of distributed applications
Orchestrate different AWS Lambdas
Visual flows
Different execution patterns (sequential, branching, parallel)
64

65. 65

66. Some lessons learned...
🚗 Think serverless as microservices " "
❄ !
🚫 Be aware of
🛠 There is still some infrastructure: use proper tools
(Cloudformation, Terraform, ...)
microfunctions
Cold starts
soft limits
66

67. Serverless architectures are COOL! 😎
Infinite scalability at low cost
Managed service
Still, has some limitations
Managing a project might be hard but:
Technology progress and open source (e.g.
Serverless.com) will make things easier
Recap
67

68. Thanks
loige.link/jsday2017 @loige
(special thanks to , & )@Podgeypoos79 @quasi_modal @augeva
Feedback joind.in/talk/79fa0
68