[Boston ACM] - Avoiding common pitfalls with modern microservices testing

From https://www.meetup.com/nejug1/events/294642505/

Have you ever wondered why your microservices break in production after all the tests have passed during CI/CD? Have you ever wondered if you’re testing too much or too little? If you want to learn about common pitfalls and how to catch them at build time rather than at runtime, this session is for you!

In this session we’ll share some common battle scars from our experiences in the field. Additionally, we will introduce the testing pyramid and explain why it is important in helping to continuously deploy microservices independently without fear. We will demonstrate, through a test-driven development approach, how the combination of Pact contract testing combined with Quarkus developer joy can help prevent your microservices from breaking in production.

Transcript

1. Eric Deandrea Sr. Principal Developer Advocate Red Hat @edeandrea Avoiding common pitfalls with modern microservices testing Drawings by Holly Cummins
2. @edeandrea #RedHat
3. @edeandrea #RedHat “Every time we touch one microservice, all the others break.”
4. @edeandrea #RedHat
5. @edeandrea #RedHat “My end-to-end test environment is only up the third weekend every month.”
6. #RedHat @edeandrea Disclaimer!
7. #RedHat @edeandrea Disclaimer! I am not a tester. (or even test expert)
8. #RedHat @edeandrea Disclaimer! I am not a tester. (or even test expert) That’s ok– testing is every developer’s job!
9. @edeandrea #RedHat Why is testing microservices so hard?
10. @edeandrea #RedHat Netflix microservice architecture
11. @edeandrea #RedHat Death star “That’s no moon. It’s our architecture.”
12. @edeandrea #RedHat Do microservices solve all problems?
13. @edeandrea #RedHat A microservice system: a portrait
16. @edeandrea #RedHat Netflix microservice architecture
17. @edeandrea #RedHat Netflix microservice architecture Testing with microservices is easy!
18. @edeandrea #RedHat Netflix microservice architecture Testing with microservices is easy! My services are so small! Everything is decoupled!
19. @edeandrea #RedHat Netflix microservice architecture Testing with microservices is easy! My services are so small! Everything is decoupled! But….. If you only test the points, And not the lines…. Does the thing actually work?
20. @edeandrea #RedHat distributed != decoupled
21. @edeandrea #RedHat Understand the coupling
22. #RedHat @edeandrea “It is all that is left unsaid upon which tragedies are built.” - Kreia, Star Wars Knights of the Old Republic II: The Sith Lords
23. #RedHat @edeandrea
24. #RedHat @edeandrea This is not the answer.
25. #RedHat @edeandrea “You lied to me. How many other lies have I been told by the Council? And how do you know that you even have the truth?” – Anakin Skywalker
26. #RedHat @edeandrea “Many of the truths that we cling to depend on our viewpoint.” — Obi-Wan Kenobi, Return of the Jedi
27. #RedHat @edeandrea “In my book, experience outranks everything.” — Captain Rex, The Clone Wars
28. @edeandrea #RedHat Ok, so how do we try these out?
29. #RedHat @edeandrea Get good at testing.
30. #RedHat @edeandrea Get good at testing. And automation.
32. end-to-end tests high realism high value
33. end-to-end tests unit tests low effort high realism high value
34. end-to-end tests unit tests integration tests low effort high realism high value
35. end-to-end tests unit tests integration tests low effort high realism
36. end-to-end tests unit tests integration tests low effort high realism tests with application server test REST endpoints tests with a database
37. #RedHat @edeandrea their code our code Why mocks aren’t enough
38. #RedHat @edeandrea our mock our code Why mocks aren’t enough
39. #RedHat @edeandrea our mock our code ✔ tests Why mocks aren’t enough
40. #RedHat @edeandrea our mock our code Why mocks aren’t enough
41. #RedHat @edeandrea our mock our code ✔ tests ✘ reality our code their actual code Why mocks aren’t enough
42. @edeandrea #RedHat a mock stormtrooper
43. @edeandrea #RedHat a mock stormtrooper “Aren’t you a little short for a stormtrooper?” – Princess Leia
44. #RedHat @edeandrea https://www.flickr.com/photos/jdhancock/4811282106 Source: https://medium.com/jung-skywalker/star-wars-symbology-luke-han-and-how-to-face-the-abyss-e9fa966319b5
45. @edeandrea #RedHat Demo The limitations of unit tests https://github.com/edeandrea/pact-quarkus-wookie-carpet-demo
46. @edeandrea #RedHat “Will someone get this big walking carpet out of my way?” – Princess Leia Demo The limitations of unit tests https://github.com/edeandrea/pact-quarkus-wookie-carpet-demo
47. @edeandrea #RedHat “Will someone get this big walking carpet out of my way?” – Princess Leia Demo The limitations of unit tests https://github.com/edeandrea/pact-quarkus-wookie-carpet-demo
48. @edeandrea #RedHat A potential solution
49. @edeandrea #RedHat How to test a fire alarm?
50. @edeandrea #RedHat
51. @edeandrea #RedHat How NOT to test a fire alarm!
52. @edeandrea #RedHat
54. Unit testing a fire alarm
55. @edeandrea #RedHat uh … is that enough?
56. @edeandrea #RedHat
57. @edeandrea #RedHat contract testing a fire alarm
58. Photo: https://www.westcoastfirepits.com/shop/death-star
59. Photo: https://www.westcoastfirepits.com/shop/death-star How to SAFELY burn a Death Star!
60. end-to-end tests unit tests integration tests low effort high realism high value
61. end-to-end tests unit tests integration tests low effort high realism high value contract tests
62. #RedHat @edeandrea our code their code A better mock
63. #RedHat @edeandrea our code their code contract test mock functional test A better mock
64. #RedHat @edeandrea ✔ our tests ✔ their tests ✔ reality our code their code contract test mock functional test A better mock
65. #RedHat @edeandrea our code their code A better mock
66. #RedHat @edeandrea our code their code contract test mock functional test A better mock
67. #RedHat @edeandrea ✔ our tests ✘ their tests ✘ reality our code their code contract test mock functional test A better mock
68. #RedHat @edeandrea A better mock our code their code
69. #RedHat @edeandrea A better mock our code their code contract test mock functional test
70. #RedHat @edeandrea ✘ our tests ✔ their tests ✘ reality A better mock our code their code contract test mock functional test
71. @edeandrea #RedHat Pact Contract Testing
72. @edeandrea #RedHat Demo
73. @edeandrea #RedHat “Help me, Pact! You’re my only hope!” – Princess Leia (almost) Demo
74. @edeandrea #RedHat “Uh, you’re telling me that consumers can break a provider’s tests?”
76. #RedHat @edeandrea Consumer-driven contract testing
77. #RedHat @edeandrea consumer Consumer-driven contract testing
78. #RedHat @edeandrea contract consumer tests mock declare (Pact) Pact file Consumer-driven contract testing Spring Cloud Contract Pact
79. #RedHat @edeandrea contract consumer tests provider mock declare (Pact) contract tests verify Pact file Consumer-driven contract testing Spring Cloud Contract Pact Pact
80. #RedHat @edeandrea contract consumer tests provider mock declare (Pact) contract tests verify Pact file Consumer-driven contract testing ☑ rich semantic testing Spring Cloud Contract Pact Pact
81. #RedHat @edeandrea contract consumer tests provider mock declare (Pact) contract tests verify Pact file Consumer-driven contract testing ☑ rich semantic testing ☑ provider can ‘develop to the contract’ instead of developing speculatively (TDD) Spring Cloud Contract Pact Pact
82. #RedHat @edeandrea contract consumer tests provider mock declare (Pact) contract tests verify Pact file Consumer-driven contract testing ☑ rich semantic testing ☑ provider can ‘develop to the contract’ instead of developing speculatively (TDD) ⛔ existing spec assets cannot be re-purposed Spring Cloud Contract Pact Pact
83. #RedHat @edeandrea contract consumer tests provider mock declare (Pact) contract tests verify Pact file Consumer-driven contract testing ☑ rich semantic testing ☑ provider can ‘develop to the contract’ instead of developing speculatively (TDD) ⛔ existing spec assets cannot be re-purposed ⛔ provider needs to know who consumers are Spring Cloud Contract Pact Pact
84. #RedHat @edeandrea contract consumer tests provider mock declare (Pact) contract tests verify Pact file Consumer-driven contract testing ☑ rich semantic testing ☑ provider can ‘develop to the contract’ instead of developing speculatively (TDD) ⛔ existing spec assets cannot be re-purposed ⛔ provider needs to know who consumers are ⛔ consumers can break provider CI Spring Cloud Contract Pact Pact
85. #RedHat @edeandrea …but I want to just use Swagger/OpenAPI
86. @edeandrea #RedHat Is Pact always the best choice?
87. #RedHat @edeandrea Provider-driven contract testing
88. #RedHat @edeandrea consumer provider Provider-driven contract testing
89. #RedHat @edeandrea contract consumer provider OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs
90. #RedHat @edeandrea contract consumer provider contract tests verify OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs Schemathesis Microcks
91. #RedHat @edeandrea contract consumer tests provider mock contract tests verify OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs Prism Microcks Schemathesis Microcks
92. #RedHat @edeandrea contract consumer tests provider mock contract tests verify OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs ☑ familiar contract format Prism Microcks Schemathesis Microcks
93. #RedHat @edeandrea contract consumer tests provider mock contract tests verify OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs ☑ familiar contract format ☑ provider does not need comms with consumers Prism Microcks Schemathesis Microcks
94. #RedHat @edeandrea contract consumer tests provider mock contract tests verify OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs ☑ familiar contract format ☑ provider does not need comms with consumers ⛔ provider does not get insight into how API is being used (deprecation is harder) Prism Microcks Schemathesis Microcks
95. #RedHat @edeandrea contract consumer tests provider mock contract tests verify OpenAPI Provider-driven contract testing generate (OpenAPI snapshot of current implementation) other protocol specs ☑ familiar contract format ☑ provider does not need comms with consumers ⛔ provider does not get insight into how API is being used (deprecation is harder) ⛔ spec-based tests lack functional depth Prism Microcks Schemathesis Microcks
96. #RedHat @edeandrea Is OpenAPI enough? It has the same syntax, but the semantics are different.
97. #RedHat @edeandrea Is OpenAPI enough? It has the same syntax, but the semantics are different. It looks the same, but the behaviour is different.
98. #RedHat @edeandrea Is OpenAPI enough? It has the same syntax, but the semantics are different. It looks the same, but the behaviour is different. Looks like a storm trooper. Behaves like Luke. (because it it is Luke)
99. @edeandrea #RedHat Demo: Semantic testing with Pact
100. #RedHat @edeandrea how annoying, the provider is returning 204. the contract expects 404, so my test is broken. quarkus will return 204 by default. 204 vs 404 - it’s more about the theory behind REST...if a caller asks for a resource the server doesn't have, it should be a 404 - same way if a user types in an invalid URL into the browser ugh, it’s too late at night to care about REST theory. I’m just going to update the expectations in the test to match reality. what?! why is my other contract test broken now? 
 oh … because what I’m changing is a mock…. Based on a true story….
101. @edeandrea #RedHat
102. @edeandrea #RedHat soo … microservices testing is hard limit end-to-end testing mocks will not be enough contract testing can rescue you
103. @edeandrea #RedHat ® Thank you! @edeandrea
104. @edeandrea #RedHat Additional Resources
105. #RedHat @edeandrea https://github.com/quarkusio/quarkus-super-heroes More realistic sample application (fewer wookies)
106. #RedHat @edeandrea Kubernetes Native Java with Quarkus Deployment Developer Joy • Quickly & easily build Kubernetes-Native Java applications • Industry leader in startup time and memory utilization for native and JVM applications • One step native executable generation • Leverage existing Java, Jakarta, MicroProfile, & Spring expertise • Imperative & reactive APIs side-by-side • Live coding with zero config https://www.infoq.com/articles/native-java-quarkus
107. #RedHat @edeandrea https://www.oreilly.com/library/view/reactive-systems-in/9781492091714 https://developers.redhat.com/e-books/understanding-quarkus https://developers.redhat.com/e-books/practising-quarkus