AWS Lambda and Serverless framework: lessons learned while building a serverless company

Planet9energy.com is a new electricity company that is building a sophisticated analytics and energy trading platform for the UK market. Since the earliest days of the company we took the unconventional decision to go serverless and finally we are building the product on top of AWS Lambda and the Serverless framework using Node.js. In this talk we will 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 auto-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.

Thanks to Padraig O'Brien and Luciano Mammino for speaking this month.

Speakers Bio:

Padraig O'Brien

Podge @Podgeypoos79 is a software engineer for over 15 years, most of that was spent developing in .NET and SQL Server, designing and building large scale data intensive applications. Lately he has shifted towards open source technologies and is spending most of his time learning Node.js, Scala and cool data tech like Spark, Cassandra. He is also working on a “super-secret” project called UnicornDB, don’t tell anybody!

In his spare time he helps out with organising some meetups like NodeSchool Dublin, NodeSchool Dun Laoghaire and teaching Kanban via Agile Lean Ireland.

Luciano Mammino

Luciano @loige is a Software Engineer born in 1987, the same year that the Nintendo released “Super Mario Bros” in Europe, which, “by chance” is his favourite game! His primary passion is code and he is extremely fascinated by the web, smart apps and everything that's creative like music, art and design. He started coding at the age of 12 using his father's old i386 provided only with DOS and the qBasic interpreter.He is a senior software developer at Planet9Energy in Dublin and he loves JavaScript (React/Node.js). He is also the co-author of "Node.js design patterns" 2nd edition (Packt, http://amzn.to/1ZF279B).

Hosted by Intercom, sponsored by Nearform and organised by Node.js Dublin (https://www.meetup.com/Dublin-Node-js-Meetup/events/236870576/)

Transcript

1. AWS Lambda &
   Serverless framework
   Lessons learned while building a serverless company
   26/01/2017
   @Podgeypoos79 - @loige
   

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2. Luciano Mammino
   ● @loige on Twitter
   ● Lmammino on GitHub
   ● Blog at loige.co
   ● Co-author of:
   Node.js Design Patterns (Second Edition)
   

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3. 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
   

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

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5. planet9energy.com
   

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7. 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 )
   

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8. ● 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
   

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9. Early experiments
   

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10. Current Technology
    

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11. “Serverless”
    Meaning
    Serverless framework
    AWS Lambda
    

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12. What does
    “serverless” mean?
    

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13. Why Serverless
    framework?
    

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14. Anatomy of Serverless.yml
    Serverless.yml header
    

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15. Defining functions and events
    

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16. Why?
    

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17. What is a lambda?
    ● Function as a service (FAAS)
    ● Pay for invocation / processing time
    ● Virtually “infinite” auto-scaling
    ● Focus on business logic, not on servers
    daaaa!
    

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18. 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…)
    

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19. Anatomy of a Lambda in Node.js
    

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20. Some use cases
    ● REST over HTTP (API Gateway)
    ● SNS messages
    ● Schedule/Cron
    ● DynamoDB data changes
    ● S3 files changes
    ● IoT
    

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21. HTTP REQUEST - API Call
    POST /hello/Elvis?foo=bar
    {
    “test”: “body”
    }
    

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22. Security
    Authentication
    Authorization
    Sensitive data
    

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23. Authentication
    (JWT tokens) Custom
    “authorizer lambda”
    “Who is the current user?”
    

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24. Users
    API 1
    Authentication
    Authorizer
    API 2
    API 3
    Credentials
    API
    Request
    JWT token
    JWT token
    Verify credentials
    Validate token
    & extract userId
    User: Podge
    Pass: Unicorns
    

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25. Authorization
    “Can Podge trade for Account23 ?”
    User Action Resource
    

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26. 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 *
    ... ... ...
    

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27. ACL Lib Example
    

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28. Environment variables
    

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30. Quality
    Testing
    Continuous Integration
    Deployment
    

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31. Testing
    JEST Node-TAP
    

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32. 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
    

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33. ● 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
    

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34. Functional test with sls invoke local
    

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35. Building the project
    

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36. Babel custom preset (transpile to Node 4.3.2)
    

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37. Build process
    JSdoc
    Up to 90% code size reduction
    Using Webpack 2 “tree-shaking”
    

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38. 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
    

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39. Deployments
    local test dev qa production
    Deploy lambdas and React apps
    

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42. Downloading the artifact from CircleCI
    

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43. Deploying the code using Serverless
    

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44. Developer Experience
    Local development
    Debugging
    Monitoring
    

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45. ● 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
    

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46. Serverless Plugins
    

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47. Serverless Offline
    

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48. Serverless Api Gateway Logs
    

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49. Serverless Mocha
    

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50. Monitoring
    

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62. Cost
    The formula
    Cost forecasts
    

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63. $ = Time * Memory * Invocation
    

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64. http://serverlesscalc.com
    

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65. Our current Lambda costs
    

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66. Lessons learned
    ( we found out…)
    

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67. DEBUGGING
    

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68. How do we do debug then...
    ● console.log …
    ● Using debug module
    ● Enabling detailed logs only when needed (per feature)
    

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70. Learn Cloudformation
    

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73. Api Gateway
    Custom domain mapping
    It is a manual step…
    

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

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75. 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
    

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76. AWS Soft limits
    http://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html
    

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77. Cold starts...
    ☃
    

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

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79. serverlessbeer.com
    is a real thing!
    Well… it’s not, but it’s a good idea!
    (read the tutorial)
    

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80. 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
    

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81. Planet 9 Energy tech-team
    We are
    hiring :)
    Peter Saŝa Podge Luciano YOU?
    Alberto Joe Domagoj
    Hugh Gus Ruth
    Check out
    Loki.js
    

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82. THANK YOU
    Planet9energy.com - tech@planet9energy.com
    Special Thanks to @johnbrett_
    Use the ,
    Luke!
    

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