apidays LIVE Paris 2021 - APIs and the Future of Software December 7, 8 & 9, 2021 Using OpenAPI to configure your API Gateway Ole Lensmar, CTO at Kubeshop

1. Using OpenAPI to configure
your API Gateway
Ole Lensmar, CTO, Kubeshop
github.com/kubeshop/kusk

2. OpenAPI driving the API Lifecycle

3. OpenAPI driving the API Lifecycle

4. Recap - what does an API Gateway do?
● Basic functionality
○ Routing / mapping
○ Rate-limiting / timeouts
○ Authentication / CORS
● Advanced
○ Security (intrusion detection, etc)
○ Orchestration/Aggregation
○ Transformation
○ Validation
○ etc.
github.com/kubeshop/kusk
Kusk

5. Potential overlap with OpenAPI
● An OpenAPI definition contains metadata on:
○ Operations / paths / methods / parameters
○ Message format (JSON Schema)
○ Security Schemes
● OpenAPI Extensions can be used/defined for adding arbitrary metadata
○ Additional security
○ SLAs (SLA4OAS)
○ Rate-limits, timeouts
○ etc
github.com/kubeshop/kusk
Kusk

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7. Wouldn’t it be great if you could use your OpenAPI
definition to configure your API Gateway?
github.com/kubeshop/kusk
Kusk

8. OpenAPI driving your API Gateway - why?
● One source of truth→ the OpenAPI definition defines both functional and
operational aspects of an API
● Ease collaboration
for involved stakeholders (dev, test, ops, doc, etc)
● “DevOps” automation→ use GitOps/CI/CD to configure your API
-Gateway
○ Ensure that runtime configuration is in sync with the actual API
○ Empower dev teams to iterate rapidly without DevOps involvement
○ Configure adjacent infrastructure; monitoring, analytics, security, etc.
github.com/kubeshop/kusk
Kusk

9. Approaches to using OpenAPI for Gateway Configuration
1. Import OpenAPI and refine with gateway
-specific configuration/UI
with/without gateway-specific OpenAPI Extensions
1. Generate standalone gateway configuration from OpenAPI
with/without gateway-specific OpenAPI Extensions
1. Gateway uses OpenAPI natively for configuration
with gateway-specific OpenAPI Extensions
github.com/kubeshop/kusk
Kusk

10. ● Pros:
○ Easy to get started with gateway from OpenAPI
○ Access to all gateway features
● Cons
○ Doesn’t always work with iterative/automated workflow
○ OpenAPI is not the source
-of-truth
● Very common approach
○ AWS
○ Azure
○ Google
○ Tyk.io
○ Gloo
○ and many more...
Import OpenAPI and Refine..
github.com/kubeshop/kusk
Kusk

11. Generate Gateway configuration from OpenAPI
● Pros:
○ Makes OpenAPI definition the source of truth
○ Automatable / iterative development
○ GitOps compatible in Kubernetes context
● Cons:
○ Needs extensions for Gateway functionality
○ Extra step to generate and apply configuration
● Generator frameworks
○ Swagger
-codegen
○ OpenAPI
-generator
● Let’s get back to this...
github.com/kubeshop/kusk
Kusk

12. Gateway uses OpenAPI natively for configuration
● Pros:
○ OpenAPI is the source of truth
○ Harness OpenAPI metadata for QoS functionality
○ Supports automated/iterative workflows
○ GitOps compatible in Kubernetes context
● Cons
○ Needs extensions for Gateway functionality
○ “Shoehorning”- should all configuration really be in the OpenAPI definition?
● Examples? Let’s get back to this one..
github.com/kubeshop/kusk
Kusk

13. API Gateways and Kubernetes
github.com/kubeshop/kusk
Kusk

14. API Gateways and Kubernetes
● Kubernetes generally requires an
Ingressto
expose an API outside a cluster
● An Ingress Controllerprovides the actual
Ingress implementation; Nginx-Ingress is the
most common, others are Ambassador,
Traefik, etc.
● API Gateways for K8s are usually Ingress
Controllers also
github.com/kubeshop/kusk
Kusk

15. Challenges specific to Ingress Controllers
● The Ingress specificationlacks many features often needed to expose APIs
in
production (being complemented/replaced by the Gateway API)
● Each Ingress controller has their own configuration file(s) / format(s) /
approaches to provide extra/unique functionality
● Due to the nature of Kubernetes and adoption of GitOps
, Ingress controllers are
generally CRD/configuration driven
-> Configuring Ingress Controllers is often done by Ops- while evolving the API
is done by Dev -> workflow contention
github.com/kubeshop/kusk
Kusk

16. Wouldn’t it be great if you could use OpenAPI
to configure your Ingress Controller?
1. One source
-of-truth!
2. No new configuration files!
3. Less YAML!
github.com/kubeshop/kusk
Kusk

17. Introducing Kusk!
● Kusk generates Ingress Controller configurations from OpenAPI/Swagger definitions
● Kusk makes your
OpenAPI definition the source of truth
for configuring:
○ Operation routing and availability
○ Rate-limiting
○ CORS
○ Timouts
○ And more...
● Kusksupports multiple Ingress controllers
: Ambassador 1.x / 2.x, Linkerd, Ingress
-
Nginx, Traefik, <your favorite here>
github.com/kubeshop/kusk
Kusk

18. Kusk Extension
● OpenAPI Extension
for:
○ Rate-limiting
○ Timeouts
○ CORS
○ Disable individual paths/operations
○ Cluster-specific properties
● Applies across all supported
Ingress Controllers- as applicable
github.com/kubeshop/kusk
Kusk

19. Why use Kusk?
● Configuring / changing Ingress Controllers is tedious
○ Different formats
○ Multiple files
○ Inconsistent feature-sets
○ More people- More YAML!
● Kusk only requires you to extend your OpenAPI definition with additional metadata
○ No new configuration files to learn
○ Keep all API
-metadata in one place
○ Consistent approach to configuring QoS features for supported Ingress Controllers
● Kusk enables an iterative GitOps/CI/CD workflow for (Open)API development
github.com/kubeshop/kusk
Kusk

20. Kusk + OpenAPI -> GitOps
github.com/kubeshop/kusk
Kusk

21. Short Demo!
github.com/kubeshop/kusk

22. Introducing: Kusk Gateway
● An OpenAPI
-first Ingress Controller / API Gateway
● Built on Envoy, a battle-tested, and production-ready proxy
● Works both standalone for local development and as Ingress Controller
under Kubernetes
● Alpha-version available on GitHub
: github.com/kubeshop/kusk -gateway
github.com/kubeshop/kusk
Kusk

23. Kusk Gateway - Why?
● Your OpenAPI definition becomes the source
-of-truth for both functional and
QoS/deployment aspects of your API
● You canrapidly iterate on your APIwithout having to require DevOps resources
● You won’t have to write boilerplate code for functionality that Kusk Gateway can
provide out-of-the-box based on the OpenAPI definition:
request-validation,
mocking, metrics/analytics, security
, etc.
github.com/kubeshop/kusk
Kusk

24. Thank You!
Github: github.com/kubeshop/kusk
Discord:bit.ly/kubeshop-discord
Kubeshop:kubeshop.io
Presenter: Ole Lensmar
Come to our virtual booth to learn more - and get a demo!

25. 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