Confidently Releasing Microservices With Consumer Driven Contracts

Many teams working with microservices need confidence they don't break functionality when making changes. System integration tests, functional tests, and sometimes manual tests are older ways to obtain that confidence. These processes may take more than 1 day or even more if different teams or a different company own the services.

To ensure the same level of confidence and speed up delivery, we can create Contracts for integrations between consumers and providers. Contracts created by consumer services need to pass with every build going in production to guarantee the integrations between systems/services work fine. Checking these contracts in a CI/CD pipeline makes feedback loops even faster.

A Contract is a collection of agreements between a Consumer and a Provider that describes the interactions that can take place between them. Consumer Driven Contracts (CDCs) is a pattern that drives the development of the Providers from its Consumer's point of view. It is TDD for microservices.

This talk covers an end to end demo of contract testing between two microservices to show how to release microservices with confidence, get early feedback, speed up delivery, and comparison with other testing strategies.

Transcript

1. GopinathLangote Confidently Releasing Microservices With Consumer Driven Contracts Software Engineer
2. Confidently Releasing Microservices With Consumer Driven Contracts
3. Confidently Releasing Microservices With Consumer Driven Contracts
4. Confidently Releasing Microservices With Consumer Driven Contracts
5. Confidently Releasing Microservices With Consumer Driven Contracts Client / Consumer Server / Provider
6. Confidently Releasing Microservices With Consumer Driven Contracts
7. Payments Team Growth Team Problem Statement
8. Refactoring
9. Unit Tests Mocked Integration Tests Functional Tests Manual Tests Test Pyramid
10. Unit Test Limited to method level Not aware of other service Trustworthy
11. Mocked Integration Test
12. Mocked User Service Not aware of other service Changes No Feedback Loop Trustworthy Mocked Integration Test
13. Real User Service Time Consuming Longer Feedback Loop Trustworthy Functional Test
14. Manual Test
15. Unit Tests Contract Test Functional Manual Tests Test Pyramid
16. Account Service Consumer Service Contract Test User Service Producer Service Payments Team Growth Team
17. Consumer Contract Test Register expectation Request Account Service User Service Mock Contract Server TEST Response Contract File
18. User Service Get the contracts Assert the expectations from consumer Consumer Provider Mock Contract Server Account Service Provider Verification
19. Initialize Mock Server
20. Setup Expectations
21. Running Test
22. Demo Consumer Contract Test
23. Get the contracts Assert the expectations from consumer Provider Service Provider Verification
24. Provider Verification
25. Demo Provider Verification
26. Provider State
27. Setup Provider State
28. CDC In Action
29. Test As Part Of Source Code Separate Contract Test Code Consumer Test
30. Cloud Storage Contract Brokers Contract Sharing
31. Contract Verification Test External tools Provider Verification
32. Against Current Build Provider Verification In CI Against Stable Build
33. Tools
34. 1. JVM 2. .Net 3. Ruby 4. Go 5. JavaScript 6. Python 7. Php 8. Swift You can implement you own https://pact.io Pact
35. Other Tool janus VCR PACTO
36. Convince Me https://docs.pact.io/faq/convinceme
37. Resources https://github.com/gopinath-langote/Pact-JVM-Implementation https://pact.io https://martinfowler.com/articles/microservice-testing/ https://www.martinfowler.com/articles/consumerDrivenContracts.html
38. Questions?
39. Thank You GopinathLangote