The document discusses Spring Cloud Gateway and API gateways. It provides an overview of what an API gateway is and its responsibilities, including routing, security, monitoring, resiliency and more. It then details the basics of Spring Cloud Gateway, including its reactive foundation and gateway flow involving predicates, filters and handlers. Finally, it discusses design decisions and provides a demo of Spring Cloud Gateway routing requests between services and integrating with Cloud Foundry.

1. Living on the Edge
with Spring Cloud Gateway
By Ryan Baxter
@ryanjbaxter

2. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/

3. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/

4. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Gateway Basics

5. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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What Is An API Gateway?
Server Side
MVC App
Microservice A
JS or Mobile
App
Microservice B
Microservice C

6. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
What Is An API Gateway?
Server Side
MVC App
Microservice A
JS or Mobile
App
Microservice B
Microservice C
Gateway

7. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Gateway Responsibilities
● Routing
● Security
● Monitoring
● Canarying
● Monolith Strangling
● Resiliency

8. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Spring Cloud Gateway Basics

9. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Spring Cloud Gateway Foundations

10. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Reactive Gateway

11. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Gateway Flow
Client Predicates Pre-Filters Global Filters
Post-Filters
Downstream
Service
Gateway
Handler Mapping Web Handler

12. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Gateway
Gateway Flow
Client Predicates Pre-Filters Global Filters
Post-Filters
Downstream
Service
Handler Mapping Web Handler
Predicates
● Path
● Host
● Date/Time
● Method
● Headers
● Query Params
● Cookies
● Read Body
● Anything….

13. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Gateway
Gateway Flow
Client Predicates Pre-Filters Global Filters
Post-Filters
Downstream
Service
Handler Mapping Web Handler
Pre-Filters
● Headers
● Path
● Rate Limiting
● Cookies
● Hystrix
● Modify Body
● Anything

14. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Gateway
Gateway Flow
Client Predicates Pre-Filters Global Filters
Post-Filters
Downstream
Service
Handler Mapping Web Handler
Global Filters
● Netty Router
● Web Sockets
● Load Balancer
● Metrics

15. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Gateway
Gateway Flow
Client Predicates Pre-Filters Global Filters
Post-Filters
Downstream
Service
Handler Mapping Web Handler
Post Filters
● Set status
● Headers
● Cookies
● Anything...

16. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Design Decisions

17. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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App
Embedded
Gate
way
Sample Use Case
● When latency is essential - no added network hops

18. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Embedded
App
Sample Use Case
● Fine-grained access control for pay-per-use
service or fragile backing service
App
Gate
way App
Gate
way App
Gate
way
App

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Facade
Gateway AppClient
Sample Use Cases
● Prevent direct access to apps
● Polyglot compatible

20. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Facade
Gateway App BClient
Sample Use Cases
● Cross-cutting concerns
● Present common API to clients
● Shield clients from app refactoring
(monolith → microservices)
App C
App A

21. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Cross-Cutting + App-Specific
App-Specific
Gateway
App B
Client
Sample Use Cases
● Delegate cross-cutting concerns to a separate
common gateway (and a separate dev team!)
App C
App A
App-Specific
Gateway
App E
App F
App D
Common
Gateway

22. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Demo
Photo Credit: Aerosmith, Living On The Edge

23. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Demo Architecture
Gateway
Blue
Service
Green
Service
Frontend
App
Client
Service
Discovery
(Eureka)

24. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Demo Architecture
Gateway
Blue
Service
Green
Service
Frontend
App
Client
Service
Discovery
(Eureka)
Yellow
Service

25. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Demo Part II:
Gateway On Cloud Foundry

26. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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User Stories - Subscription SLA Management
● As a consumer, I want features in accordance with my subscription.
● As a developer, I want to focus on my app.
● As a product owner, I want to ensure a consistent and unified consumer experience.
● As an operator, I want the the solution to be resilient and scalable.

27. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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configs:
- name: trial
replenishRate: 2
burstCapacity: 2
- name: basic
replenishRate: 10
burstCapacity: 15
- name: premium
replenishRate: 50
burstCapacity: 100
Consumers… need subscriptions
Trial
Basic
Premium

28. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Developers want…
Aut t a n
Aut za
Rat i n
Req En i h t
Req For d
…as a service

29. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Product Owners want… consistency
Open Service
Broker API
Instances
Bindings
Catalog

30. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Operators want… resilience and scalability
3
0

Rate Limiters
(Redis)
Service
Instance Info
(MongoDB)
Service Broker + Gateway

31. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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To the demo...

32. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Thank You

33. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Feedback Please!

34. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
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Q&A
Spring Cloud Gateway: https://github.com/spring-cloud/spring-cloud-gateway
Session Code: https://github.com/MrBW/chaos-monkey-spring-boot-demo
Slides: https://speakerdeck.com/ryanjbaxter

35. > Stay Connected.
#springone@s1p

36. Unless otherwise indicated, these slides are © 2013-2018 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license:
http://creativecommons.org/licenses/by-nc/3.0/
Cross-Cutting + App-Specific
App-Specific
Gateway
App B
Client
App C
App A
App-Specific
Gateway
App E
App F
App DCommon
Gateway
Service Broker
(OSBAPI)
Cloud
Foundry
Service
Instance Info
Rate
Limiters
Sessions