The document discusses the evolution of cloud-native API gateways, emphasizing the impact of microservices, Kubernetes, and changing workflows on API management. It outlines the historical changes from hardware to software load balancers and the shift from centralized to decentralized management approaches. The future challenges include scaling edge management and supporting diverse requirements, along with strategies to address these challenges in Kubernetes environments.

1. The Past, Present, and Future of
Cloud Native API Gateways
Daniel Bryant

2. tl;dr
• Edge and API gateways have undergone a series of evolutions,
driven by architecture and technology
• Adopting microservices, Kubernetes, and cloud changes the workflow
• Chose your Kubernetes API gateway (and platform) intentionally
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3. @danielbryantuk
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4. 4
Edge: The boundary between your
data center and your user(s)

5. 5
Thesis:
The evolution of the edge has been driven by
application architecture and technology

6. 6
~1995

7. Application Architecture in the ‘90s
7

8. Hardware Load Balancer
8
User Systems administrators
Purpose High availability / scalability
Key Features
Load balancing
(round robin, sticky sessions)
Health checks

9. 9
~2000

10. Similar application architecture
10

11. 11
20022001

12. Software Load Balancer
12
User
Systems administrators
(“pre DevOps”)
Purpose High availability / scalability
Key Features
Load balancing
Health checks
Observability

13. 13
~2005

14. 14

15. 15
Ecommerce
0
75
150
225
300
2000 2005 2010 2015 2019
Amazon Revenue,
Billions

16. 16

17. The Application Delivery Controller (ADC)
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18. Application Delivery Controllers (ADCs)
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User Systems administrators
Purpose
High availability and
application acceleration
Key Features
SSL offload, caching,
compression + load balancing

19. 19
https://www.flickr.com/photos/pchow98/5518600886

20. 20
~2010

21. The proliferation of APIs
21
2005: API launched 2008 2009

22. API Gateway (1st Gen)
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User
Systems administrators &
API developers
Purpose
Expose business APIs to broader
ecosystem (“API management”)
Key Features
L7 routing (e.g., throttling),
Publishing, Dev Portal, Analytics,
Monetization

23. 23
~2015

24. 24

25. Mini-services
25

26. API Gateway (2nd Generation)
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27. API Gateway (2nd Generation)
27
User
Systems administrators &
API developers
Purpose
Centralize cross-cutting app
concerns
Key Features
Authentication, rate limiting,
monitoring + routing

28. 28
Cloud-native
applications

29. Cloud-Native Microservices
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• Modularisation (“microservices”)
• Built, released, & operated by
independent application teams
• Scaled independently

30. App Architecture: A Spectrum of Services
• Different locations (K8s, VMs, FaaS)
• Different protocols (gRPC, HTTP, WebSockets, TCP)
• Different load balancing requirements
(sticky sessions, round robin)
• Different authentication requirements
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31. Cloud Gateway
31
Real-time Service
Discovery
Need ADC-like traffic management
capabilities: timeouts, retries, rate
limiting, load balancing, caching, …
Need API Gateway-type
management capabilities:
authentication, developer
portal, metrics, …
1
2
3

32. Microservices lead to an even bigger change.
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33. 33
“You build it, you run it”
- Werner Vogels, CTO Amazon
i.e. you own what you code,
from idea to production

34. Workflow: Full Cycle Development
34
• App teams have full responsibility (and authority) for
delivering a service, and ultimately, value to users
• Increase agility by accelerating the feedback loop
• https://netflixtechblog.com/full-cycle-developers-at-netflix-a08c31f83249

35. 35
This is a change in workflow.

36. 36
Thesis:
The future evolution of the edge will be driven by
application architecture, technology, and workflow

37. 37
Two biggest
challenges with
k8s & the edge

38. Challenge #1: Scaling Edge Management
38
Development
Team
Operations / Platform Team

39. Challenge #1: Scaling Edge Management

40. Challenge #2: Supporting Diverse Edge Requirements
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41. 41
Three Strategies

42. Three Strategies for the Edge with Kubernetes
#1: Deploy an Additional Kubernetes API Gateway
#2: Extend Existing API Gateway
#3: Deploy an in-Cluster Edge Stack
42
https://www.getambassador.io/resources/strategies-managing-apis-edge-kubernetes/

43. #1 Deploy an Additional Kubernetes API Gateway
• Simply deploy an additional “in-cluster” gateway
• Below the existing gateway
• Below the load balancer
• Management
• Development teams responsible
• OR existing ops team manages this
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44. #1 Deploy an Additional Kubernetes API Gateway
• Pros
• There is minimal change to the core edge infrastructure.
• Incremental migration easily
• Cons
• Increased management overhead of working with
different components
• Challenging to expose the functionality to each
independent microservice teams
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45. #2 Extend Existing API Gateway
• Implemented by modifying or augmenting the existing API
gateway solution
• Enable synchronization between the API endpoints and
location of k8s services
• Custom ingress controller for the existing API Gateway or
load balancer
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46. #2 Extend Existing API Gateway
• Pros
• Reuse the existing tried and trusted API gateway
• Leverage existing integrations with on-premises
infrastructure and services
• Cons
• Workflows must change to preserve a single source of
truth for the API gateway configuration.
• Limited amount of configuration parameters via
Kubernetes annotations
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47. #3 Deploy an In-Cluster Edge Stack
• Deploy Kubernetes-native API gateway with
integrated supporting edge components
• Installed in each of the new Kubernetes clusters,
replacing existing edge
• Ops team own, and provide sane defaults
• Dev teams responsible for configuring the edge
stack as part of their normal workflow
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48. #3 Deploy an In-Cluster Edge Stack
• Pros
• Edge management is simplified into a single stack
• Supports cloud native best practices: “single
source of truth”, GitOps etc
• Cons
• Potentially a large architectural/responsibility shift
• Platform team must learn about new proxy
technologies and edge components
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49. 49
Wrapping Up

50. In Conclusion
• Edge/API gateways have undergone a series of evolutions, driven by architecture and tech
• Hardware -> software
• Networking Layer 4 -> Layer 7
• Centralized management -> decentralised
• Adopting microservices/Kubernetes changes workflow
• Scale edge management
• Support multi-protocol and cross-functional requirements
• Chose your cloud API gateway (and platform components in general) intentionally
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51. app.getambassador.io
thenewstack.io/learning-kubernetes-the-need-for-a-realistic-playground

52. Many thanks!
• Learn more:
• www.getambassador.io/learn/building-kubernetes-platform
• www.getambassador.io/podcasts
• www.infoq.com/profile/Daniel-Bryant
• Find me in:
• Datawire OSS Slack: d6e.co/slack
• Twitter @danielbryantuk
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