API Athens Meetup - Foss Edition

1. API-led DesignMichael Petychakis, The APILama
@mpetyx.
API Athens Meetup: Foss Edition

2. Why? Avoid fail. Move fast.

3. What are APIs?
• When we talk about APIs we are talking about “Web” APIs.
• Bits of logic that encapsulate the data they operate on and provide an interface
as the only way to access their functionality.
API-led design means:
1. Starting the solution design process with APIs and
2. Crafting APIs rather than throwing them up.
Back up a bit

4. API rock-stars

5. • Increase Agility
• Consume rather than build.
• New business models
• Self-service IT
• Composable Enterprise
• Mobile enablement
• Parallel development
• Governance & Control
Why APIs?

6. What is Design?
• ‘Making things better for people' - Richard Seymour, Design Council 2002
• Design is a work process which has a user perspective and drives development based on
your specific customers’ needs
Who is the API Customer?
Developers? The Business? Both?
Back up a bit more

7. We all like good design

8. Good design:
1. Is innovative
2. Makes a product useful
3. Is aesthetic
4. Makes a product
understandable
5. Is unobtrusive
1. Is honest
2. Is long-lasting
3. Is thorough down to the last
detail
4. Is environmentally friendly(?)
5. Is as little design as possible
10 Commandments of good design
- Dieter Rams. Design legend.

9. • Alignment between Business, Stakeholders & IT
• APIs are crafted in response to a customer need rather than generated from a developers
code (hide your complexity).
• Quicker and cheaper to make change during design phase.
• Once it’s code it takes longer (even if you have great DevOps)
• Allows engagement with Customers in the creation of the API.
• Prototyping.
• Enables parallel development of front-end and back-end.
• Self-documenting.
Why lead with API Design?

10. •Typically code your web services and pull them up into an API
specification.
•Focus is on the service developer not on the API consumer.
•Result is an API that shows all of the complexity in your
codebase and domain.
•Result is nasty APIs. Poor engagement. Fail.
What’s the alternative?

11. 5 steps:
1. Create high-level domain model (get the language right).
2. Model the state (get the actions right).
3. Create the API outline in an API specification language.
4. Verify that the specification conforms to domain. Update if needed.
5. Flesh out the specification with low-level “developer” detail.
API Design methodology

12. • Avoid dumping the whole Domain into the API.
• Avoid “Fat” APIs that cover too many Domains
 eg. /flights, /employees, /invoices all in the one API
 Fat APIs change too frequently. Favour multiple smaller APIs with
fewer owners.
• Avoid inconsistent naming
 eg. resourcename not resourceName, resource-name, resource_name.
 eg. passenger, pax, customer, cust – pick one. “Ubiquitous language”
API Design anti-patterns
12

13. • RAML stands for RESTful API Modeling Language.
• Based on YAML, so if you like tabs….
• Open specification created by MuleSoft
• Alternatives: Swagger, API Blueprint, WADL(?)…etc
• Mule Anypoint API Designer (free) has great RAML editor.
• Can mock out API once specified.
• Can generate code (eg. JAX-RS, Go) from RAML.
• Generates excellent documentation with live interaction.
RAML

14. •API-led design isn’t about adding roadblocks.
•It’s about crafting something that will have value.
Conclusion

15. First Steps

16. What’s Docker?
• API to provide lightweight containers
• Opensource platform
• Run process isolated in the same host
• It helps to deploy, ship, test, etc. in a fast way

17. How it works

18. How it works

19. How it works
• Dockerfile: set of instructions to build a docker image. Every instructions
creates a new layer and it is assigned to a hash, like a git commit
• Docker Hub: Central repository where docker images are stored

20. Docker is NOT a Virtual Machine

21. Docker vs. Virtual Machines
Virtual Machine

22. Docker vs. Virtual Machines
Docker containers

23. Advantages
• High level abstraction for containers
• Fast to create images
• Fast to deploy
• Reduce time between development and deployment
• Possible to have several environments isolated in the same host

24. Example

25. So… Docker is AWESOME!!!!!!!!!

26. Well… Not that awesome…

27. Disadvantages
• Networking limitations
• No support for IPv6
• Uses NAT
• Insecure (Trust Docker Hub)
• No support for old kernels
• Not easy to debug
And more… http://www.boycottdocker.org

28. Docker in Production

29. Tools
• CoreOS, RancherOS, boot2docker
• Kubernetes
• Docker Machine
• Docker Compose
• Kitematic

30. Questions?

31. Thank you!
Michael Petychakis
@mpetyx
hello@apilama.com
http://apilama.com/