Workshop - Mocks as Code. Modeling services in Config Management integration tests

When managing service configurations at scale, we often need to automate testing of these configurations. In software integration testing, we can use Testcontainers - a popular framework for Docker and other container engines. For public cloud environments, there is LocalStack. And for API service providers, we have WireMock. Can we use the same toolchain for configuration management? If you use modern Infrastructure-as-Code tools like Pulumi, yes!

In this edition, we will use Java or Kotlin for EVERYTHING, from the application itself and all the way up to Infrastructure as Code definitions and tests.

In this workshop, we will go through the following topics:
1. Containerizing Spring app development
2. Integration testing with Testcontainers and LocalStack
3. Mocking APIs with WireMock
4. Infrastructure as Code (IaC) with Pulumi and Pulumi for Java
5. Testing IaC locally, with all tools above combined

See https://github.com/oleg-nenashev/mocks-as-code-demo for the demo repository we will be using in this workshop. It also contains all the links to the used tools and additional learning materials.

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Transcript

1. Oleg Nenashev, @oleg_nenashev CNCF Ambassador
2. > whoami @oleg_nenashev oleg-nenashev Dr. Nenashev / Mr. Jenkins Community builder Developer Tools Hacker #RussiansAgainstPutin #StandWithUkraine
3. Async Q&A: Testcontainers Slack speakerdeck.com/onenashev
4. 5 Staging & QA Tests Build Integration tests Build Tests Gaining confidence in you software “Shift Left” with modern tools
5. “Shift Left”, they said? YAML, they gave? 6
6. 7 Java All the Way Down Up Application Unit Tests Build Definition and Pipelines Integration Tests Infrastructure-as-Code Deployment Pipelines Deployment Tests Production Health Checks Java the stack up all the way
7. Today 8 1. Containerizing Spring App Development 2. Integration testing with Testcontainers and LocalStack 3. Mocking APIs with WireMock 4. Infrastructure as Code (IaC) with Pulumi 5. Testing IaC locally 6. Advanced Troubleshooting Localstack
8. Our Repository github.com/oleg-nenashev/mocks-as-code-demo git clone it
9. Workshop Prerequisites • Internet :( • Java 17 & your favorite IDE • Testcontainers-compatible Docker environment ◦ Tested on: Docker Desktop ◦ You can use: Podman, Colima, Rancher Desktop (list) ◦ OR: Testcontainers Cloud • Pulumi CLI + registration ◦ Guide: www.pulumi.com/docs/install/ 10
10. Our Application 11
11. 12 AWS S3 SQS External API Our Application
12. Credits 13 • Siva Prasad Reddy and Oleg Shelajev, Docker • The demos are based on: ◦ github.com/testcontainers/tc-guide-testing-aws-service-integrations-using-loca lstack ◦ github.com/testcontainers-community/testcontainers-wiremock-demo
13. Integration Testing? 14 github.com/oleg-nenashev/mocks-as-code-demo/ tree/main/2_api_mocking
17. Ways to do API integration testing 1. Testing against Production/Staging servers 2. Testing against a simplified/containerized instance (e.g. Testcontainers) 3. Modeling (aka Mocking) at the API provider level (e.g. WireMock or Microcks) 4. Mocking at the code level Slow Fast Nope Accu- rate * For Testcontainers, see the slides
18. 19 https://martinfowler.com/articles/ mocksArentStubs.html
20. 21 SDKs testcontainers.org … and
21. 22 github.com/testcontainers/ testcontainers-go
22. Example - Java 23
23. 24 LOCAL STACK LocalStack Module K3s Module
24. 25 Localstack www.localstack.cloud
25. LocalStack • Local AWS Services emulation OR mocking • “awslocal” CLI utility • SDKs for languages and test frameworks 26 docs.localstack.cloud/
26. 27 x.com/dastbe/status/1303858170155081728
27. Some of Them 28 • Emulated: S3, SQS, … • Mocked: EC2 (in the FOSS lib) • Thoughts & Prayers: AWS GreenShift ;) • …
28. Demo Time 29 github.com/oleg-nenashev/mocks-as-code-demo/ tree/main/1_application
29. No Implementation? 30 Fake it until you “$ make it”
30. Ways to do API integration testing 1. Testing against Production/Staging servers 2. Testing against a simplified/containerized instance (e.g. Testcontainers) 3. Modeling (aka Mocking) at the API provider level (e.g. WireMock or Microcks) 4. Mocking at the code level Slow Fast Nope Accu- rate * For Testcontainers, see the slides
31. wiremock.org/docs/stubbing IF (request_url) THEN (response) * * it gets MUCH more complex WireMock Config JSON: Client library response request Client App Mock API Server HTTP/2 API Mocking 101
32. API Mocking Tools Main implementation in Java Native lib, Docker images and Testcontainers modules Support for GraalVM Rich Ecosystem Sandbox CNCF Project Golang / Microservice arch Docker image, Testcontainers module, All-in K8s Charts Less Rich Ecosystem
33. WireMock Ecosystem & Features wiremock.org/docs
34. WireMock Ecosystem wiremock.org/docs
35. WireMock in Java wiremock.org/docs/stubbing
36. WireMock Ecosystem / Java • Java • Kotlin • Scala • Groovy • Clojure • (?)Android 37 • JUnit 4/5 • Testcontainers • Sprint Boot • Spring Cloud Contract • Quarkus • Maven / Gradle Build Tool • Spock • Pact
37. Example - JUnit 5 38
38. 39 WireMock has an official Testcontainers module! testcontainers.com/modules/wiremock
39. Demo Time 40 github.com/oleg-nenashev/mocks-as-code-demo
40. 41 Infrastructure-as-Code, for real
42. 43 And more constructive!
43. HOWTO: JavaDev-Ops 44
44. Enter -as-Code Tools! • Infrastructure as Real Code • SDKs for programming languages • Standard IDEs • Standard Developer Tools • Extensibility via libraries 45
45. • Open-Ecosystem Tool for Infra-as-Code • Open Source SDKs 46
46. • Multiple destinations 47 www.pulumi.com
47. • 120+ extensions: www.pulumi.com/registry/ 48 www.pulumi.com
48. Pulumi for Java 49 pulumi.com/docs/languages-sdks/java/
49. build.gradle 50
50. 51 Java All the Way Down Up Application Unit Tests Build Definition and Pipelines Integration Tests Infrastructure-as-Code Deployment Pipelines Deployment Tests Production Health Checks Java the stack up all the way
51. 52 Localstack
52. Pulumi Local • github.com/localstack/pulumi-local • Setting the environment and the configuration right • Just a script 53 Localstack
55. Hacking Time! 56 github.com/oleg-nenashev/mocks-as-code-demo/ tree/main/3_deployment
56. When it Goes wrong 57
60. Demo Time 61 github.com/oleg-nenashev/mocks-as-code-demo
61. Lessons Learned 62
62. Beware Pulumi for AWS Native • AWS Native configuration is not applied for endpoints • APIs are slightly different in the package 63
67. 68 Java All the Way Down Up Application Unit Tests Build Definition and Pipelines Integration Tests Infrastructure-as-Code Deployment Pipelines Deployment Tests Production Health Checks Java the stack up all the way
68. What I’m looking forward to? • Feedback from Java developers • Is Infra-as-Code with Java interesting to you? • Do you want Pulumi-LocalStack for Java productization? • Any other feedback on dev tools :)
69. References • Main Demo: github.com/oleg-nenashev/mocks-as-code-demo • This presentation: speakerdeck.com/onenashev/ workshop-mocks-as-code-in-cfg-mgmt
70. Keep Learning Tools 71 * AKA: Burning Out 101
72. It’s [always] a great time to contribute! testcontainers.org/contributing wiremock.org/participate 73
73. GitHub: oleg-nenashev Twitter: @oleg_nenashev Questions? 74