apidays LIVE Paris 2021 - APIs and the Future of Software December 7, 8 & 9, 2021 OpenAPI Generator - The Babel Fish of the API World Cliffano Subagio, Principal Engineer at Shine Solutions

1. Open API Generator
The Babel Fish of the API World
Cliffano Subagio | Shine Solutions
Apidays Live Paris | 7-9 December 2021

2. About
Cliffano Subagio
Principal Engineer at Shine Solutions, Australia
Member of OpenAPI Generator Technical Committee

3. Agenda
1. The polyglot systems and the Babel fish
2. Intro to OpenAPI Generator
3. My use case scenarios
4. Wrap up + let’s contribute

4. 1. The polyglot systems and the Babel Fish

5. New York
JULY
Australia
SEPTEMBER
Singapore
APRIL
Helsinki & North
MARCH
Paris
DECEMBER
London
OCTOBER
Jakarta
FEBRUARY
Hong Kong
AUGUST
JUNE
India
MAY
Check out our API Conferences here
50+ events since 2012, 14 countries, 2,000+ speakers, 50,000+ attendees,
300k+ online community
Want to talk at one of our conferences?
Apply to speak here

6. © 2020 Shine
Solutions Group
Back in the 2000s,
I was a Java developer
5
• Monolithic J2EE applications
• 100% pure Java mindset
within the community

7. Java Monolithic Application
6
Java

8.
YOW! 2012 talks
by Fred George
Micro Services Architecture
Language agnostic services
Programmer Anarchy
Use of Ruby, Clojure, C++, Node.js

9. Polyglot Multi Services
8
Ruby
Clojure
node.js Go
Python
Java
.NET

10. If you stick one
in your ear
The Babel fish

11. You instantly
understand
anything sent to you
in any language

12. Polyglot Multi Services
11
Ruby
Clojure
node.js Go
Python
Java
.NET

13. 2. Intro to OpenAPI Generator

14. OpenAPI Generator
13
• Open source code generator library
• Written in Java, uses Mustache templates
• Generates API clients, server stubs, docs
• Supports 40+ tech stacks
• Community fork of Swagger CodeGen
• 10k+ GitHub stars
2k+ contributors

15. How does it work?
14
OpenAPI
Specification
OpenAPI
Generator
API
Clients
API
Servers
API Docs
Swagger-Parser
Generator
Templates

16. Example: ipify
15
api.ipify.org
GET / ?format=json
200 OK
{ “ip”: “60.240.197.183” }

17. OpenAPI specification
16
metadata
paths
responses
schemas
parameters

18. Running the generator
17

19. Running the generator
18

20. What will be generated?
19
• Project structure
• OpenAPI Generator metadata
• README
• CI config
• Library dependencies
• Documentation
• Unit tests
• API client:
Clients, data models
• API server stubs:
Endpoints, controllers, payloads

21. Generated API clients
20
Python Ruby node.js

22. Generated API clients
21
Java

23. Example Ruby API client
22

24. Supported tech stacks
23

25. 3. My use case scenarios

26. SOA with custom ESB (mostly Java)
25
ESB
Identity
Service
Adapter
Service
Data
Service
Consolidation
Service
Routing
Service
Message
Service
Monitor
Service

27. SDK Clients for a REST API
26
API Gateway (OpenAPI)
node.js Python Go Java

28. Infrastructure as Code
27
Legacy
Enterprise
Application
CLI (node.js)
Ruby
API Client
Python
API Client
SpringBoot App
(Java)
Ansible Playbook
Puppet Module
InSpec Profile

29. Performance testing
28
Web
App
JMeter
JMX
CSV

30. Jenkins CI/CD
29
Swaggy-
Jenkins
CLI
Smart Light
Notifiers
Voice
App

31. Top three maintenance tips…
30
1. Integration testing
2. Integration testing
3. Integration testing

32. 31
OpenAPI Spec v2 OpenAPI Spec v3
OpenAPI Generator v2 OAG v3 v4 v5
Python 2 Python 3
Ruby 1.9 Ruby 2.3 Ruby 2.5 Ruby 2.6
My application changes
Dependency Vulnerabilities
Environment changes
Changes happen all the time!

33. 4. Wrap up + let’s contribute

34. Remember the Babel fish?
33
Ruby
Clojure
node.js Go
Python
Java
.NET

35. OpenAPI Generator
34
https://openapi-generator.tech
• Multi tech-stacks support
• Boilerplate code for free
• Massive time saver

36. My first contribution
35
I optimised file downloading
in Ruby API client’s

37. Failed to allocate memory at 2Gb

38. 100Mb+ memory consumption

39. Your contributions are welcomed!
https://github.com/OpenAPITools/
openapi-generator

40. Helping OpenAPI Generator
If you find OpenAPI Generator useful,
please consider becoming a sponsor.
https://opencollective.com/
openapi_generator

41. Thank you! Any questions?
cliff.subagio@shinesolutions.com
linkedin.com/in/cliffano/

42. Resources
https://openapi-generator.tech/
https://github.com/OpenAPITools/openapi-generator/
https://en.wikipedia.org/wiki/
The_Hitchhiker%27s_Guide_to_the_Galaxy#Future_predictions
https://www.youtube.com/watch?v=YWqHkYtREAE
https://www.youtube.com/watch?v=cbFLGv41vBA
https://www.youtube.com/watch?v=sns1DknIwhQ
https://opencollective.com/openapi_generator
https://en.wikipedia.org/wiki/OpenAPI_Specification
https://swagger.io/specification/
https://github.com/cliffano/openapi-ipify
https://github.com/cliffano/swaggy-jenkins
https://github.com/shinesolutions/swagger-aem
https://pixabay.com/photos/boat-shell-rowing-rowers-sport-3404551/

43. New York
JULY
Australia
SEPTEMBER
Singapore
APRIL
Helsinki & North
MARCH
Paris
DECEMBER
London
OCTOBER
Jakarta
FEBRUARY
Hong Kong
AUGUST
JUNE
India
MAY
Check out our API Conferences here
50+ events since 2012, 14 countries, 2,000+ speakers, 50,000+ attendees,
300k+ online community
Want to talk at one of our conferences?
Apply to speak here