WireMock8s - Mocking your APIs in Kubernetes

Distributed and microservice architectures are all about APIs these days, whether you use gRPC, REST API, Websockets or any other interface. There are tools for integration testing that involve API providers, including mocking them based on OpenAPI specifications. There are even Kubernetes native tools like Microcks that are scalable and provide valuable features and observability out of the box. More classic tools, including my favorite WireMock, are available on Kubernetes too.

If you’ve ever developed for JVM or .NET stacks, most likely you’ve heard about WireMock. It is a popular open-source tool and framework for API mock testing, with over 5 million downloads per month. It has implementations and adapters for many languages.

In this talk, I will focus on using WireMock for testing Cloud Native applications in Kubernetes, including using it for common continuous delivery and deployment use-cases. We will see how to use WireMock as a standalone deployment, or as a part of Argo CD and Tekton pipelines. I’ll also show how these approaches can be integrated with WireMock Cloud for those who want to do distributed testing and chaos engineering.

Transcript

1. Oleg Nenashev, WireMock Inc. 1 WireMock8s Mocking your APIs in Kubernetes June 29, 2023 - Basel
2. > whoami @oleg_nenashev oleg-nenashev 2
3. WireMock Inc.? • Early stage startup • WireMock creator is a co-founder of the Inc. • WireMock Cloud - SaaS for end-to-end API mocking • Soon: K8s Edition for managed / on-premises • // We are hiring ;-) wiremock.io
4. Disclaimer • This is a talk about is NOT about “VERSUS” or “OR” • There’s comparison • Your mileage may vary
5. Outline • APIs in Cloud Native • Microcks and WireMock • Comparison • HOWTO: WireMock in Cloud Native app CI/CD These slides
6. Software ATE the world Source:developer.mercedes-benz.co m/products/vehicle_status/details
7. The new ecosystem is about APIs GROWTH IN WEB APIS SINCE 2005 Over 90% of developers use APIs. Skyrocket growth of APIs JANUARY 2006 JANUARY 2008 JANUARY 2010 JANUARY 2012 JANUARY 2014 JANUARY 2016 JANUARY 2018 MONTH The growth over time of the Programmable Web API API directory to more than 22,000 entries 22000 20000 18000 16000 14000 12000 10000 8000 6000 4000 2000 0 TOTAL API COUNT Programmable Web * Gartner Hype Cycle for APIs, 2022
8. APIs? Not just REST! • Any interface! • Async interfaces too • Binary interfaces too 8
9. Open Standards • Standard specifications for APIs • Developer tools for the specification • Ways to share specifications between teams at early stages • Tools for serving APIs based on specifications www.openapis.org www.asyncapi.com
10. Are there API Mocking tools? 10
11. 11 Of course! https://twitter.com/dastbe/statu s/1303858170155081728
12. API Mocking Landscape 12 en.wikipedia.org/wiki/Comparison_of_API_simulation_tools Kubernetes Native Not so Proprietary Open Source
13. 13 https://microcks.io
14. Microcks summary • “Open source Kubernetes Native tool for API Mocking and Testing” • Kubernetes native • Runs in Docker and OpenShift too 14 https://microcks.io
15. Congrats, Microcks!
16. Microcks in CI/CD • You provision test APIs in CI/CD on-demand • Plugins and environment wrappers • Contract testing for deployed APIs 16 https://microcks.io
17. https://wiremock.org
18. Website: wiremock.org
19. ~4M MONTHLY DOWNLOADS OF THE JAVA LIBRARY Downloads Over the Last 12 Months For com..github.tomakehurst WireMock 5K STARS IN GITHUB AND GROWING 4.0K 3.0K 2.0K 1.0K 2012 2014 2016 Date 2018 2020 2022 Star history Align timeline Start – history.com Tomakehurst/wiremock 5.0K 3,036 Used by 3,036 Open Source Projects >46M Pulls of WireMock Docker Image 181 Contributors >5M Downloads a month 1.3k Forks
20. Key features https://github.com/wiremock
22. Not just a Java tool github.com/wiremock/ecosystem
23. WireMock8s • wiremock/wiremock • wiremock/wiremock-docker • wiremock/helm-charts • wiremock/grpc-wiremock • wiremock/wiremock-testcontainers-go Full demo will be here: github.com/oleg-nenashev/wiremock8s 23
24. gRPC Adapter for WireMock 24
25. github.com/wiremock/wiremock-testcontainers-java
26. Example - JUnit 5
27. Example - Golang https://github.com/oleg-nenashev/ wiremock-testcontainers-go/
28. WireMock as a Proxy Tests Real API Provider OR
29. WireMock Proxy? Why? • Record & Playback for Request sequences • Reverse engineering of legacy undocumented APIs • Emulating complex cases ◦ Overriding particular responses ◦ Emulating response sequences / Stateful behavior ◦ Failure Injection
30. Two tools. What's the difference? 30
31. Reminder
32. 32 Deployment / Project WireMock Microcks “Baremetal” “External” projects * No JVM Yes No Docker / Container Runtimes Yes Yes K8s / Helm Yes Yes K8s Operator DIY Yes K8s / Cloud Native Scaling DIY Yes Testcontainers Yes DIY SaaS WireMock Cloud N/A Deployment * Rust implementation, .NET Core, Quarkus Native, GraalVM DIY - Do it yourself
33. Operations / Cloud Native Experience 33 Features / Project WireMock Microcks CLI Yes Yes Platform SDKs Yes Code-Generated Scale to Zero DIY Yes (operator) Horizontal scaling DIY Yes (operator) OpenTelemetry integration No Yes Configuration as Code Yes Yes
34. Features 34 Features / Project WireMock Microcks Request Matching* Yes Yes Response templating* Yes Yes Record & Playback Yes No (playback is on the roadmap) Stateful Behavior Yes No Async Behavior DIY (extension) Yes Fault Injection Yes DIY (hook) Chaos Engineering Yes (WireMock Cloud) DIY (hook) * WireMock is more powerful for HTTP(s), but less - for gRPC
35. Protocols 35 Features / Project WireMock Microcks HTTP / REST API * Yes Yes HTTPs / SSL Yes Yes gRPC Adapter Yes GraphQL Yes (extension) Yes Async API Adapter => AWS SNS/SQS, Kafka, RabbitMQ, NATS, PubSub, MQTT No Yes CloudEvents PoC Yes (blog) Websockets No Yes * WireMock is more powerful for HTTP(s), but less - for gRPC
36. Add more Chaos… Engineering! * Available in WireMock Cloud
37. Developer Experience 37 Features / Project WireMock Microcks Web UI WireMock UI*, WireMock.NET, WireMock Cloud Yes Editor / IDE integrations WireMocha for IDEA, VSCode plugins, OpenAPI Tooling Async API and OpenAPI tooling Reusable Templates Repo Yes Yes (Just Starting) REST API and OpenAPI Reverse Engineering WireMock Cloud No * Unofficial
38. There’s no silver bullet 38
39. Comparison - TL;DR • Microcks is cloud native and K8s native • Microcks supports more protocols OOTB • Microcks implements Async API events • WireMock can be used in a cloud native way • WireMock is more powerful as Mocking tool ◦ Better form matching ◦ Record & Playback capabilities ◦ Stateful behavior • WireMock embeds in Unit/Integration tests 39
40. WireMock in K8s App CI/CD? 40
41. 41 Testcontainers + WireMock (Docker engine is needed) My approach - Choosing Deployment I. Tests inside Java / JVM? II. Other stack? Use WireMock classic (WireMock Java) III. Single team / workspace? IV. Bigger setups? Use WireMock Standalone With Helm / Crossplane / etc.
42. 42 Demo time!
43. Repeat after me? 43 • WireMock Cloud - Free Tier available, use it ◦ https://www.wiremock.io/product • Demo repository: TODO
44. WireMock8s. What’s next? 44
45. Public Roadmap https://github.com/orgs/wiremock/projects/4
46. WireMock8s initiatives 46 • Testcontainers Go module 1.0 • Helm Chart 1.0 • Better extensions support • Better observability / sub-events • Native gRPC and CloudEvents mocking • (?) OpenFeature adoption
47. WireMock Cloud. K8s Edition 47 Coming Soon! Subscribe - https://share-eu1.hsforms.com/1YS KnSP93Tsig1JoO3lXSawfbdiq
48. Takeaways • API Mocking/Abstraction are great • There is no silver bullet • There are tools for Kubernetes! • If you need a cloud native tool OOTB - Microcks • WireMock can be made cloud native too • WireMock Cloud if you need SaaS
49. References WireMock • Website: wiremock.org • Docs: wiremock.org/docs • WireMock on K8s: wiremock.org/docs/solutions/kubernetes/ • WireMock Cloud: www.wiremock.io/product • WireMock and Testcontainers Microcks • Website: microcks.io • Docs: microcks.io/documentation 49
50. It’s [always] a great time to contribute! wiremock.org/participate
51. THANK YOU Contacts: E-mail: oleg@wiremock.org GitHub: oleg-nenashev Twitter: @oleg_nenashev QUESTIONS?