Leveling a Serverless application’s design using Hexagonal architecture - NodeConfEU 2019

Serverless is becoming one of the most relevant technologies in this era. One year and a half ago, I started to develop AWS Lambda functions with node.js with no idea of what challenges I was about to face.

With portability as the priority, and after a couple of iterations, and our learnings from three stories, we discovered the concepts behind Hexagonal architecture that helped us to re-use the main’s application logic behind different AWS services and avoid hight complex test.

Transcript

2. 2 Sebastián Osorio - Software Engineer at @Skycatch Co-organizer GDLJS Insta|Twitter: @sirgalleto - galleto.xyz
4. Flavors of: Leveling your Serverless application's design using hexagonal architecture @sirgalleto studios 4
7. Some time ago... 7
10. 10 Get the cloud into the site
11. 11 * Works with and without network connection * Maps & point clouds in 30 minutes * AI on the Edge * GNSS RTK base station
14. 14 Learn Practice Add value Side project > Decrease food waste > Improve food experience
15. 15 We need an API!
16. 16 *We gained some visibility *We got a commitment *We got a humble budget to maintain some stages.
18. 18 *Problems managing the stages... and the deployment. *Over use of the humble budget. *Still have a commitment.
19. 19 A user is going to use the application a couple of times per week. ~300 usage peaks/week. We're paying for servers 24/7 per 3 stages. We're spending a considerable amount of time to maintain the environment. We do this for love, and sometimes we have no time/resources.
20. 20 * Free tier * Easy management
24. 24 Changes in the environment = Refactor time
29. 29 Migration ready in less than a week
31. Startup X 31 * Based on a real story
32. 32 *Local startup. * They had a global competitor. *Be the first => need velocity => Used a service that increased the development velocity. *They did it!!! .
35. 35 * No-one died on this story
36. 36 Learn time
37. 37 Your application will always change. Code will change. Environment will change.
38. 38 New project
39. Serverless 39 *POC inside the organization *The application change every week *KAOS
40. 40 40
42. 42 What do I want?
43. Isolate what is more important: The business logic 43
44. I'm no the first one here... 44
45. 45 *Boundary-Controller-Entity, Ivar Jacobson, 1992 *Hexagonal Architecture, Alistar Cockburn, 2005 *Jeffery Palermo, Onion Architecture, 2008 *Robert C. Martin, Screaming Architecture, 2011
46. Hexagonal architecture 46 https://madewithlove.be/hexagonal-architecture-demystified/ INSIDE
47. 47 Hexagonal architecture https://madewithlove.be/hexagonal-architecture-demystified/ CORE Transformer Transformer
48. Ports and Adapters 48
49. 49 Ports and adapters architecture
50. 50 Test Database File System Web service
51. 51 GraphQL Database Test
52. 52 https://vacationtracker.io/blog/startups-can-benefit-from-serverless/
53. Service Trigger
54. Service Trigger apiGatewayPort.js s3EventPort.js stepFunctionEventPort.js { "path": "/hello", "headers", "pathParameters", "requestContext", "httpMethod": "GET", }
55. Service Trigger apiGatewayPort.js core.js s3EventPort.js stepFunctionEventPort.js { "path": "/hello", "headers", "pathParameters", "requestContext", "httpMethod": "GET", } { ...payload }
56. Service Trigger apiGatewayPort.js core.js s3EventPort.js stepFunctionEventPort.js outsidePort.js { "path": "/hello", "headers", "pathParameters", "requestContext", "httpMethod": "GET", } { ...payload } .callMe()
57. 57 Service Trigger apiGatewayPort.js core.js s3EventPort.js stepFunctionEventPort.js outsidePort.js { ...response } { ...outsideResponse }
58. 58 * The core logic is available with a simple contract easy to define and consume. * Concentrate the team effort on create test important to the business. * Execute the code in your/any machine. * Calls the outside world using a well defined interface as port. core.js 1. * (Make sure to manage errors)
59. 59 * A single piece of code that handles the definition of any event that your business logic can run. * You test what concerns to the definition of the service. _port.js 2.
61. 61 *Rules easy to share & apply. *Portable code. *Tested code. ...
62. 62 For the next iteration of your application don't talk about a refactor, talk about an adaptation
63. 63 Credits.
64. 64 Latin-America ecosystem
65. 65 > An amazing company is always open for amazing people Come and talk with us
66. 66 Thanks.