AWS Lambda &Serverless framework Lessons learned while building a serverless company

26/01/2017@Podgeypoos79 - @loige

Luciano Mammino

● @loige on Twitter

● Lmammino on GitHub

● Blog at loige.co

● Co-author of:

Node.js Design Patterns (Second Edition)

Padraig O’Brien (a.k.a “Podge”)

● @podgeypoos79 on Twitter

● Does not have a book (yet…)

● Organiser of Nodeschool Dublin and Dun Laoghaire

● Organiser of Dublin Serverless meetup

● He is writing his own database, unicorndb �

Agenda

● Planet 9 Energy● Serverless● Security● Quality● Developer Experience● Costs● Lessons learned

planet9energy.com

17.520 * * 24

Meter readings Customer size Data versions

≈4 billion data pts / year (tot.)

SMALL customer ≈3 mln data pts / year MEDIUM customer ≈20 mln data pts / year BIG customer ≈110 mln data pts / year

( Per customer / year )

● Limited number of “Full stack” engineers

● Write & deploy quality code as fast as possible

● Adopt hot and relevant technologies

● No servers... or more to the point, NO CALLS AT 2 AM!

Our requirements

Early experiments

Current Technology

“Serverless”Meaning

Serverless frameworkAWS Lambda

What does “serverless” mean?

Why Serverless framework?

Anatomy of Serverless.yml

Serverless.yml header

Defining functions and events

Why?

What is a lambda?

● Function as a service (FAAS)

● Pay for invocation / processing time

● Virtually “infinite” auto-scaling

● Focus on business logic, not on serversdaaaa!

Lambda as micro-services

● Events are first-class citizens● Every lambda scales independently● Agility (develop features quick and in an isolated fashion)

Classic micro-services concerns:

● Granularity (how to separate features? BDD? Bounded Contexts?)● Orchestration (dependencies between lambdas, service discovery…)

Anatomy of a Lambda in Node.js

Some use cases

● REST over HTTP (API Gateway)

● SNS messages

● Schedule/Cron

● DynamoDB data changes

● S3 files changes

● IoT

HTTP REQUEST - API Call

POST /hello/Elvis?foo=bar

{ “test”: “body”}

SecurityAuthentication AuthorizationSensitive data

Authentication

(JWT tokens) Custom“authorizer lambda”

“Who is the current user?”

Users

API 1

Authentication

AuthorizerAPI 2

API 3

CredentialsAPI

Request

JWT token

JWT tokenVerify credentials

Validate token& extract userId

User: Podge Pass: Unicorns

Authorization

“Can Podge trade for Account23 ?”

User Action Resource

Authorization

● Custom ACL library imported by every lambda

● Built on top of:

○ node-acl

○ Knex.js

● Persistence in Postgres

User Action Resource

Podge trade Account23

Podge changeSettings Account23

Luciano delete *

... ... ...

ACL Lib Example

Environment variables

QualityTesting

Continuous IntegrationDeployment

Testing

JEST Node-TAP

Unit Testing

● Split business logic into small testable modules

● Use dependency injection for external resources

(DB, Filesystem, etc.)

● Mock dependencies with Sinon

● Aim for 100% coverage

● Use child_process.exec to launch “serverless invoke local”

● Use node-tap to make assertions on the output

● Test environment recreated locally with docker (e.g. Postgres test DB).

● Cannot always test locally (Redshift, SNS, SQS…)

Functional Testing

Functional test with sls invoke local

Building the project

Babel custom preset (transpile to Node 4.3.2)

Build process

JSdoc

Up to 90% code size reductionUsing Webpack 2 “tree-shaking”

Continuous Integration

Git-Flow● Check code style (ESLint)

● Run unit tests

● Build the project

● Run functional tests

● If commit is on “master”:

Create deployable artifact

● Develop features/fixes locally

using git branches

● Push to GitHub

Deployments

local test dev qa production

Deploy lambdas and React apps

Downloading the artifact from CircleCI

Deploying the code using Serverless

Developer ExperienceLocal development

DebuggingMonitoring

● Develop locally - Invoke local.

● Deploy to AWS.

● Invoke on AWS and stream the logs.

● This is a SLOW feedback loop.

● Lots of requests to improve local dev.

● Plugins are helping to improve this.

Local development

Serverless Plugins

Serverless Offline

Serverless Api Gateway Logs

Serverless Mocha

Monitoring

CostThe formula

Cost forecasts

$ = Time * Memory * Invocation

http://serverlesscalc.com

Our current Lambda costs

Lessons learned( we found out…)

DEBUGGING

How do we do debug then...

● console.log … �

● Using debug module

● Enabling detailed logs only when needed (per feature)

Learn Cloudformation

Api GatewayCustom domain mapping

It is a manual step…

With Api Gateway...You have 10 30 seconds!

AWS Lambda limitations

● 512 MB of TMP space

● Lambdas can only execute for 300 seconds

● Request Response size of 6 MB

● Event size of 128 Kb

● Max 50 MB for deployment package

AWS Soft limits

http://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html

Cold starts...

☃�

https://www.iopipe.com/2016/09/understanding-aws-lambda-coldstarts/

serverlessbeer.com

is a real thing!

Well… it’s not, but it’s a good idea!

(read the tutorial)

Recap

● 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 projects (Serverless.com) will make things easier

Planet 9 Energy tech-team

We are hiring :)

Peter Saŝa Podge Luciano YOU?

Alberto Joe DomagojHugh Gus Ruth

Check outLoki.js

THANK YOU

Planet9energy.com - tech@planet9energy.com

Special Thanks to @johnbrett_

Use the , Luke!