CTO of Smart Gamma will talk In this speech about the problems that arise when testing applications built on a microservices architecture. We will conduct a brief overview of how to test the interaction between microservices. We will also talk in details about Consumer-Driven Contract Testing with an example of using the pact.io

1. Contract testing. Isolated testing of microservices with pact.io
Evgeniy Kuzmin,CTO at Smart Gamma

2. Product Quality
- How we can measure product quality?
- Which metrics can describe product quality?

3. Bugs
- What is main reason of bugs?

4. Complexity
- How to control complexity?

5. Do microservices resolve complexity problem?

6. Integration Hell - how to avoid it?

8. Project V1 - monolith version
- Fuel control / GPS position system
- in-house fuel control hardware
- TomTom GPS position system as data gateway
- Monolith architecture for data processing via
WebFleet API
- UI customers area

9. Classic monolith testing
- Stable 3rd party API
- Classic testing requirements and approaches
- Data flows modeling before hardware is functional

10. Project’s evolution V2
- New 2nd sub-system for agriculture
- Extendable to 3rd sub-system for industry
- Own data processing system via GSM instead of
TomTom
- Universal hardware for all sub-
systems
- Hardware shop

11. End-2-end testing for data routing feature
- Mock entry point API with emulated flow
- Required etalon data fixtures preload or setup via QA API
- Setup test infrastructure with all services deployed
- Execute test
- Assert all expected behavior

12. End-2-end testing pros and cons
Trustfull
Create
Execute
Assert
Support
Detect reasons

13. Testing triangle problem
- Goal: keep time of feedback from test suite fast

14. Integration testing
- Narrow execution area
- Narrow assertion area

15. Integration testing

16. Mock testing
- Fast
- Easy to create
- Environment independent

17. Mock testing problems
- Control mock “expiration”

18. Mock Device Registry v 1.0

19. Mock testing problems

20. What is a solution?
- Consumer-driven contracts
- Provider-driven contracts

21. https://docs.pact.io
“Do you set your house on fire
to test your smoke alarm?”
Pact PHP: https://github.com/pact-foundation/pact-php

22. Each consumer captures their expectations of the provider in a separate contract
Consumer-Driven Contracts

23. Pact framework
- Pact is contract testing framework
- Contract is a collection of
interactions.
- Each interaction consist of
expected request and minimal
expected response.

24. Pact framework
- Pact is contract testing framework
- Contract is a collection of
interactions.
- Each interaction consist of
expected request and minimal
expected response.

25. Pact framework
- Pact is contract testing framework
- Contract is a collection of
interactions.
- Each interaction consist of
expected request and minimal
expected response.

26. Pact framework
- Pact is contract testing framework
- Contract is a collection of
interactions.
- Each interaction consist of
expected request and minimal
expected response.

27. Pact framework
- Pact is contract testing framework
- Contract is a collection of
interactions.
- Each interaction consist of
expected request and minimal
expected response.

28. https://gist.github.com/Evgenas/ef21e19cfa894507d091985c45bddf12

29. https://gist.github.com/Evgenas/ef21e19cfa894507d091985c45bddf12

30. Pact Response Matchers

31. Matchers force to keep the proper schema

32. Matchers force to keep the proper schema

33. https://gist.github.com/Evgenas/ef21e19cfa894507d091985c45bddf12

34. https://gist.github.com/Evgenas/ef21e19cfa894507d091985c45bddf12

35. Mock server

36. Result of interaction builder at Pact contract file

37. https://gist.github.com/Evgenas/ef21e19cfa894507d091985c45bddf12

38. https://gist.github.com/Evgenas/ef21e19cfa894507d091985c45bddf12

39. Verify interaction on the consumer
Verify interaction

40. Pact on Behat Scenario https://github.com/smart-gamma/pact-behat-extension

41. Pact on Behat Scenario https://github.com/smart-gamma/pact-behat-extension

42. Pact on Behat Scenario https://github.com/smart-gamma/pact-behat-extension

43. Pact on Behat Scenario https://github.com/smart-gamma/pact-behat-extension

44. Pact on Behat Scenario https://github.com/smart-gamma/pact-behat-extension

45. Pact on Behat Scenario https://github.com/smart-gamma/pact-behat-extension

46. Writing Pact json file locally

47. Needs to define BROKER_URI

48. Pact Broker Service

49. Brocker Web UI
Docker image: https://github.com/DiUS/pact_broker-docker

50. Browse Pact file

51. Provider verification

52. Provider verification
- PACT verifier, and source of contract
- Requests replay

53. Verify provider - Phpunit test on provider side

54. Required data on the provider
- Needs to define provider state per test case

55. Required data on provider

56. Given - Pact State(QA API)

57. Given - Pact State(QA API)

58. Provider state
State API

59. Pact State Manager implementation on the provider side

60. Broker - result of verification
- Сonditions for passing the all test
- Services tested without real interaction

61. CI / Jenkins - Consumer flow

62. CI / Jenkins - consumer contract test

63. CI / Jenkins - trigger downstream provider job
https://gist.github.com/Evgenas/98a1a0f5d2f7665d36e430f687fbf4de

64. CI / Jenkins - Provider verify contract

65. CI / Jenkins - Resolve branches for the provider repo

66. CI / Jenkins - Resolve branches for the provider repo
https://gist.github.com/Evgenas/e9aed2460c7ba24f93c69884df9cc01a
c

67. CI / Jenkins - Provider flow

68. CI / Jenkins - Control backward compatibility by versions and tags
New consumer 1.0.2 changed schema expectation
New provider 1.0.2 changed provided schema
Provider 1.0.2 and Consumer 1.0.2 should be deployed simultaneously only!

69. https://gist.github.com/Evgenas/61ac7b6efb999896df9017194158cb4c

70. CI / Jenkins - deploy “can-i-deploy”
PACT Broker client: https://github.com/pact-foundation/pact_broker-client#can-i-deploy

71. - Replacement for functional tests of providers
- Replacement for OpenAPI/Swagger
- API for public consumers vs private consumers
What PACT is NOT:

72. evgeniy.k@smart-gamma.com
https://www.linkedin.com/in/evgeniy-kuzmin-03816a52/