Once you have your Microservices setup, the most pertinent question is how to I test Microservices and ensure that all the moving parts of this distributed system stay in sync. The presentation provides testing strategies on how to test Microservices and provides focussed understanding of using Consumer Driven Contracts (CDC) to test Microservices API. Additionally it provides pointers around how to do debug Microservices and trace the performance of individual services. Please read the following presentations before referencing "Testing Microservices" 1. Introduction to Microservices - https://www.slideshare.net/anilallewar/introduction-to-microservices-78270318 2. Build the Microservices sample application - https://www.slideshare.net/anilallewar/building-microservices-sample-application

1. Testing Microservices

2. Types of Testing
API
Service
Persistence
Database
Client
Service
Stubs
External Service
Microservice
Microservice
Domain
Unit Test
Integration Test
Component Test
Contracts
Contracts
End-to-end Test

3. Test Pyramid
Exploratory
End to end
Component /
Contracts
Integration
Unit (Solitary / Sociable)
Manual
Selenium, Appium, Sikuli,
JBehave
Spring Cloud Contract, Pact,
Cucumber
Junit, SOAPUI
Junit, Nunit, Mockito, JMock,
Lambda Behave

4. Consumer Driven
Contracts

5. Testing Services
S1
S2 S3
S4
1. Deploy all Microservices and
perform end-to-end tests
Testing Approach
1. Simulates production
2. Real communication
1. Too cumbersome – deploy DB,
all services
2. Late feedback
3. Environment blocked
4. Very hard to debug

6. Testing Services
S1
2. Mocking other Microservices in
unit/integration tests
Testing Approach
1. Fast feedback
2. No infrastructure setup
1. Stubs might be different
than the real service
2. Tests will pass but the
application might fail in
production

7. What do we need?
Producer
•Define contract
•Verify that API implementation is per contract – server tests
•Publish stub versions to repo – changes visible to both sides
Consumer
•Mock producer based on stub definitions – client integration
tests
•ATDD – Acceptance TDD

8. Consumer Driven Contracts
Consumer
Producer Repository
Acceptance
Tests
Client Test
Integration Test

9. Spring Cloud Contract Verifier
Contract Definition Language (DSL)
• Definition either in groovy or pact format
Used to produce following resources
• JSON stub definitions
 Used by client side
 Test written by hand, test data provided by Spring
• Server tests
 Test generated by Spring

10. Build script – Consumer (task-webservice)
dependencies
• testCompile("org.springframework.security:spring-security-test")
• testCompile("org.springframework.cloud:spring-cloud-starter-
contract-stub-runner")

11. Client tests
Create integration test
• Annotations
@RunWith(SpringRunner.class) // 1
@SpringBootTest(webEnvironment = WebEnvironment.MOCK, properties = {
"spring.cloud.discovery.enabled=false",
"spring.cloud.config.enabled=false","stubrunner.idsToServiceIds.basic-comments-webservice-
stubs=comments-webservice" }). // 2
@Import(OAuth2ClientTestConfiguration.class). // 3
@AutoConfigureStubRunner(ids={"anilallewar:basic-comments-webservice-stubs:+:stubs:9083"},
workOffline=true) // 4
@DirtiesContext // 5

12. Client tests
Actual test
Fails for 2 reasons
• Call is secured though OAuth2 access token
• Stub definition not available
@Test
public void testGetCommentsForTask() {
CommentCollectionResource comments =
this.commentsService.getCommentsForTask(REQUEST_TASK_ID);
Assert.assertEquals(2, comments.getTaskComments().size());
Assert.assertTrue(comments.getTaskComments().get(0).getTaskId().equals(TEST_TASK_ID));
}

13. Mock OAuth2 token
Create SecurityContext holding the mock access token
• https://spring.io/blog/2014/05/07/preview-spring-security-test-
method-security#withsecuritycontext
Code
• https://github.com/anilallewar/microservices-basics-spring-
boot/tree/master/task-
webservice/src/test/java/com/anilallewar/microservices/task

14. Run tests
Once you have the MockOAuth2 token code
• Comment the @AutoConfigureStubRunner annotation
• Run the test with ./gradlew clean build
java.lang.AssertionError: expected:<2> but was:<1>
• Circuit breaker kicked in and provided default value
Uncomment @AutoConfigureStubRunner and run the test
• Error creating bean with name 'batchStubRunner'

15. Build script – Producer (comments-webservice)
buildscript
• project.ext
 springCloudContractVesrion = '1.1.1.RELEASE'
• dependencies
 classpath "org.springframework.cloud:spring-cloud-contract-gradle-
plugin:${project.springCloudContractVesrion}”
dependencies
• testCompile('org.springframework.cloud:spring-cloud-starter-
contract-verifier')

16. Build script – Producer (comments-webservice)
// Setup the package which contains base classes that the spring cloud contract test case would extend
contracts {
packageWithBaseClasses = 'com.anilallewar.microservices.comments.contracts'
}
clean.doFirst {
delete "~/.m2/repository/anilallewar/basic-comments-webservice"
delete "~/.m2/repository/anilallewar/basic-comments-webservice-stubs"
}
// Setup the artifact id with which the stubs jar would be published, the group id comes from the 'group' attribute defined earlier
publishing {
publications {
mavenJava(MavenPublication) {
artifactId jar.baseName
version jar.version
from components.java
}
stubs(MavenPublication) {
artifactId "${jar.baseName}-stubs"
version jar.version
artifact verifierStubsJar
}
}
}

17. Contract DSL
Src/test/resources/contracts
request {
method 'GET'
url $(consumer(regex('/comments/([0-9a-
zA-z]+)')), producer('/comments/task11'))
headers {
accept(applicationJson())
}
}
response {
status 200
body( [
[
"taskId": "task11",
"comment": "comment on task11",
"posted": $(consumer('2015-04-
23'),producer(execute('convertTimeValueToDate($it)')))
]]
)
headers {
contentType('application/json')
}
}

18. Abstract Base Class
Generated test extends the defined base class
Since the package for base classes is defined
as com.anilallewar.microservices.comments.contracts and
the contract is defined under the task/comments folder
under test/resources/contracts, the base class name is
TaskCommentsBase
Add @Ignore annotation – not a test class

19. Abstract base class
Inject a WebApplicationContext so that Spring dependency is
initialized correctly.
Annotations
@RunWith(SpringRunner.class)
@SpringBootTest(classes = { CommentsApplication.class }, webEnvironment
= WebEnvironment.MOCK, properties = {
"spring.cloud.discovery.enabled=false", "spring.cloud.config.enabled=false"
})

20. Run tests
 Run the test with ./gradlew clean build
•This will generate the server tests under /comments-
webservice/build/generated-test-
sources/contracts/org/springframework/cloud/contract/verifier
/tests
 Publish the contract stub using ./gradlew
publishToMavenLocal
 Once the contract is published, go to the task-webservice
folder and run ./gradlew clean build
•This time around the test should pass

21. Distributed Tracing

22. Sleuth & Zipkin
Sleuth
• Attaches unique id to request as it passes through enabled services
• Logs can be mined using aggregation tools like ELK (ElasticSearch,
Logstash and Kibana)
Zipkin
• Distributed tracing system
• Gathers timing data across Microservices – collection and lookup

23. Dependencies
Create a new project by visiting https://start.spring.io/
• Gradle project –> with Java and Spring Boot 1.5.4
• Group -> com.<name>.microservices
• Artifact -> tracing
• Dependencies -> Zipkin UI, Zipkin Client
Additional dependency
• compile('io.zipkin.java:zipkin-server')
Run ./gradlew clean build eclipse

24. Code changes
Application.properties
• server.port=9411
Alternatively you can add configuration on the centralized
configuration server
Add @EnableZipkinServer annotation on the Spring boot
application class

25. Add Zipkin client properties
Check below properties exists in configuration files for “api-
gateway”, “comments-webservice”, “task-webservice” and
“user-webservice”
spring:
zipkin:
baseUrl: http://localhost:9411/
sleuth:
sampler:
percentage: 1.0
sample:
zipkin:
enabled: true

26. View Traces
Run all the Microservices and other servers (zipkin server,
web-portal etc)
Hit http://localhost:9411/ (Zipkin base url)
UI
• Find specific trace and timing information
• Service dependency graph
Trace id is added to logs – enables distributed log analysis

27. Sample Trace

28. Contact Me
anilallewar@yahoo.co.in
https://www.linkedin.com/in/anilallewar
https://github.com/anilallewar
http://www.slideshare.net/anilallewar
@anilallewar