Confidently Releasing Microservices With Consumer Driven Contract Testing

“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.

Happy CDC!

Transcript

1. GopinathLangote Confidently Releasing Microservices With Consumer Driven Contract Testing Gopinath Langote
2. Confidently Releasing Microservices With Consumer Driven Contract Testing @GopinathLangote Confidence has a common meaning of a certainty about handling something, such as work, family, social events, or relationships. - Wikipedia
3. Confidently Releasing Microservices With Consumer Driven Contract Testing @GopinathLangote Ability of going to production
4. Confidently Releasing Microservices With Consumer Driven Contract Testing @GopinathLangote A particular way of designing software applications as suites of independently deployable services. - Martin Fowler
5. Confidently Releasing Microservices With Consumer Driven Contract testing Client / Consumer Server / Provider @GopinathLangote Offerings, plans, or strategies motivated by customer demand or expectations.
6. Confidently Releasing Microservices With Consumer Driven Contracts testing @GopinathLangote A contract is a legally binding agreement which recognises and governs the rights and duties of the parties to the agreement. - Wikipedia
7. Payments Team Growth Team Problem Statement @GopinathLangote
8. Refactoring @GopinathLangote
9. Unit Tests Mocked Integration Tests Functional Tests Manual Tests Test Pyramid @GopinathLangote
10. Unit Test Limited to method level Not aware of other service Trustworthy @GopinathLangote
11. Mocked Integratio n Test @GopinathLangote
12. Mocked User Service Not aware of other service Changes No Feedback Loop Trustworthy Mocked Integration Test @GopinathLangote
13. Real User Service Time Consuming Longer Feedback Loop Trustworthy Functional Test @GopinathLangote
14. Manual Test @GopinathLangote
15. Unit Tests Contract Test Functional Manual Tests Test Pyramid @GopinathLangote
16. Account Service Consumer Service Contract Test User Service Producer Service Payments Team Growth Team @GopinathLangote
17. Consumer Contract Test Register expectation Request Account Service User Service Mock Contract Server TEST Response Contract File @GopinathLangote
18. User Service Get the contracts Assert the expectations from consumer Consumer Provider Mock Contract Server Account Service Provider Verification @GopinathLangote
19. 1. Setup Expectations @GopinathLangote
20. Contract @GopinathLangote
21. 2. Running Test @GopinathLangote
22. 3. Provider Verification @GopinathLangote
23. Demo Consumer Contract Test @GopinathLangote
24. CDC In Action @GopinathLangote
25. Cloud Storage Contract Brokers Contract Sharing @GopinathLangote
26. Against Current Build Provider Verification In CI Against Stable Build @GopinathLangote
27. Microservices Architecture When services are handled by multiple teams/companies When to do CDC? @GopinathLangote
28. Manually talk to concerned team/partner What if contract fails - Communication Automate communication 1. Automatic email 2. Automatic Jira tickets 3. Send alerts to slack @GopinathLangote
29. Tools @GopinathLangote
30. 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 @GopinathLangote
31. Other Tool janus VCR PACTO @GopinathLangote
32. Convince Me https://docs.pact.io/faq/convinceme @GopinathLangote
33. 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 @GopinathLangote
34. Thank You GopinathLangote