Spring Cloud Contract Car Rental

car-rental (consumer)

Sends an HTTP request to fraud detection from a test Gets a Stream message from fraud detection

fraud-detection (producer)

Producer of the HTTP api and messages

Presentation steps

Before

Start Rabbit & Eureka

$ docker-compose up -d
$ spring cloud eureka

Start.spring.io

car-rental

web, stubrunner, stream rabbit, wiremock, Eureka Discovery

and stream-test-support for Contract & Stream

		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-stream-test-support</artifactId>
			<scope>test</scope>
		</dependency>

fraud-detection

web, stream rabbit, verifier, REST Docs, wiremock, Eureka Discovery

and stream-test-support for Contract & Stream

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-test-support</artifactId>
    <scope>test</scope>
</dependency>

and plugin - REMEMBER ABOUT EXTENSIONS

<!-- ADD A PLUGIN -->
<plugin>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
    <version>${spring-cloud-contract.version}</version>
    <!-- REMEMBER ABOUT THIS LINE -->
    <extensions>true</extensions>
    <configuration>
        <baseClassForTests>com.example.frauddetection.BaseClass</baseClassForTests>
    </configuration>
</plugin>

Code

HTTP

CONSUMER

Generate consumer from start.spring.io
Add the missing dependencies
Start with a test on the consumer side
Write a not passing test to reach the /fraud endpoint of the producer
Add the WireMock stub to make the test pass (port 6543)

PRODUCER

Generate producer from start.spring.io
Add the missing dependencies
Write a contract for the /frauds endpoint (the typo is deliberate)
Configure the plugin with baseClassForTests
Run ./mvnw clean install - show breaking tests
Write the controller
Write missing base class setup
Rerun the ./mvnw clean install - things pass
Run the app at port 6544

CONSUMER

Write a new test that will reach the producer application directly (port 6544)
The previous test with a stub passes, the new one fails (oops)
Write a new test with StubRunnerRule com.example:fraud-detection at (port 6545)
The test fails cause first we’ll shoot at /fraud
The test passes once we shoot at /frauds

Messaging

CONSUMER

Enable binding for Sink
In application.properties
- set the port to 9876
- spring.cloud.stream.bindings.input.destination=fraud
- on the producer side it will be frauds
Add a Fraud pojo with a name
Add a FraudListener @Component
- with a method fraud that has @StreamListener(Sink.class)
- let it print a message out
- and store the name
Let’s write a FraudTests class
- we want to see if our listener will work fine if we send it our POJO
- let’s write a test should_store_info_about_fraud
- make it a SpringBoot test
- @Autowired FraudListener
- @Autowired Sink
- given: a new Fraud("marcin")
- when: sink.input().send(MessageBuilder.withPayload(fraud).build());
- then: fraudListener.name == "marcin"
The test passes - let’s go to the producer

PRODUCER

EnableBinding(Source.class)
Set properties
- spring.cloud.stream.bindings.output.destination=frauds
- Yup, that’s a typo over there ^^
- spring.cloud.stream.bindings.output.contentType=application/json
- server.port=6544
Let’s write a contract for messaging
- label trigger_a_fraud
- input method triggerMethod()
- output to destination frauds
- body surname: "Long"
Create a Fraud pojo in the FraudController
FraudController will need a @PostMapping("/message") method called message that will use Source to send a message with new Fraud("Long")
Let’s run ./mvnw clean install and generate tests
- they will fail cause we have a missing triggerMethod()
Let’s create the triggerMethod() in the BaseClass
- Also we need to add the Spring context with @AutoConfigureMessageVerifier
- @Autowired FraudController
- call in the triggerMethod() the fraudController.message()

Let’s try to make both apps work! Let’s run them together

curl -X POST http://localhost:6544/message

Nothing happens… Even though the tests passed. That’s for 2 reasons

the destination is wrong. One is sending to frauds the other listening to fraud
the POJO is wrong. Once expects name the other surname

Time to fix the consumer

CONSUMER

Let’s use Stub Runner
@AutoConfigureStubRunner(workOffline = true, ids = "com.example:fraud-detection")
@Autowired StubTrigger
stubTrigger.trigger("trigger_a_fraud");
- the test won’t pass - let’s update the destination
spring.cloud.stream.bindings.input.destination=frauds
- let’s run again the tests - still they don’t pass cause the name is wrong
let’s change Fraud to use surname
- now if we rerun the tests they pass

Let’s run both apps again, send the CURL - now they should work

REST Docs

PRODUCER

We need to write a test for the message endpoint
We’ll write a test called FraudControllerTests

Use the test slices AutoConfigureMockMvc and @AutoConfigureRestDocs(outputDir = "target/snippets")

@RunWith(SpringRunner.class)
@SpringBootTest(classes = FraudDetectionApplication.class)
@AutoConfigureRestDocs(outputDir = "target/snippets")
@AutoConfigureMockMvc

Write a simple test to see if status OK happens when you send a POST to /message/

@Autowired private MockMvc mockMvc;

	@Test
	public void should_accept_a_post_message() throws Exception {
		mockMvc.perform(MockMvcRequestBuilders.post("/message"))
				.andExpect(MockMvcResultMatchers.status().isOk())
				.andDo(MockMvcRestDocumentation.document("message"));
	}

Time to configure the build to package stuff properly
We want to disable the default Spring Cloud Contract packaging approach
- You can do it by setting <spring.cloud.contract.verifier.jar.skip>true</spring.cloud.contract.verifier.jar.skip> property

Add the src/assembly/stub.xml

<assembly
        xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.3"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.3 https://maven.apache.org/xsd/assembly-1.1.3.xsd">
    <id>stubs</id>
    <formats>
        <format>jar</format>
    </formats>
    <includeBaseDirectory>false</includeBaseDirectory>
    <fileSets>
        <fileSet>
            <directory>${project.build.directory}/snippets/stubs</directory>
            <outputDirectory>META-INF/${project.groupId}/${project.artifactId}/${project.version}/mappings</outputDirectory>
            <includes>
                <include>**/*</include>
            </includes>
        </fileSet>
        <fileSet>
            <directory>${project.build.directory}/stubs/META-INF/${project.groupId}/${project.artifactId}/${project.version}/mappings</directory>
            <outputDirectory>META-INF/${project.groupId}/${project.artifactId}/${project.version}/mappings</outputDirectory>
            <includes>
                <include>**/*</include>
            </includes>
        </fileSet>
        <fileSet>
            <directory>${basedir}/src/test/resources/contracts</directory>
            <outputDirectory>META-INF/${project.groupId}/${project.artifactId}/${project.version}/contracts</outputDirectory>
            <includes>
                <include>**/*.groovy</include>
            </includes>
        </fileSet>
    </fileSets>
</assembly>

Add the assembly plugin setup

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <executions>
        <execution>
            <id>stub</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>single</goal>
            </goals>
            <inherited>false</inherited>
            <configuration>
                <attach>true</attach>
                <descriptor>${basedir}/src/assembly/stub.xml</descriptor>
            </configuration>
        </execution>
    </executions>
</plugin>

Run ./mvnw clean install

CONSUMER

Reuse the previously created setup and just send a post method to /messages. Expect status 200

Discovery

CONSUMER

Add @EnableDiscoveryClient
Add @Bean @LoadBalanced for RestTemplate
Add spring.application.name=car-rental
In FraudTests we’ll add another test (we need @AutoConfigureStubRunner)
- @Autowired RestTemplate
- Use the RestTemplate to call "http://fraud-detection/frauds"
- The test passes cause SC-Contract redirects the calls via artifact id

Stub Runner Boot with Eureka and Rabbit (optional)

Clone Stub Runner for Eureka & Rabbit from https://github.com/spring-cloud-samples/github-analytics-stub-runner-boot
Build it locally
java -jar target/github-analytics-stub-runner-boot-0.0.1.M1.jar --stubrunner.workoffline=true --stubrunner.ids=com.example:fraud-detection
Show http://localhost:8083/stubs
Show http://localhost:8083/triggers
Show http://localhost:8761 with registered apps
Run car-rental
curl -X POST http://localhost:8083/triggers/trigger_a_fraud
Check that in the logs we see that a message was received
Write a test that isn’t annotated with @AutoConfigureStubRunner and inject RestTemplate - you can shoot a request to fraud-detection and a stub will respond
- or write a POST endpoint to /rent that will receive a {"name":"marcin"} and then it will call fraud-detection/frauds to retrieve a list of frauds. If that string contains the name then set status code 406 and text NO. Otherwise 200 and yes and run a curl curl -X POST -d '{"name":"marcin"}' http://localhost:8765

Stub Runner Boot with a NodeJs app

Install npm
Install the request module npm install request
Ensure that Stub Runner Boot is not running
Go to nodejs folder and execute
```
$ node app.js
```
You will get sth like this
```
ERROR - status [404]
```

Next run stub runner boot and show how easy it is to start a stub (this assumes that fraud-detection stubs were installed locally)

$ mkdir -p target
$ wget -O target/stub-runner.jar 'https://search.maven.org/remote_content?g=org.springframework.cloud&a=spring-cloud-contract-stub-runner-boot&v=1.2.3.RELEASE'
$ java -jar target/stub-runner.jar --stubrunner.workOffline=true --stubrunner.ids="com.example:fraud-detection:+:9876"

or use docker (we’re mounting your local .m2 to the docker’s .m2)

#!/bin/bash
# Provide the Spring Cloud Contract Docker version
SC_CONTRACT_DOCKER_VERSION="1.2.4.BUILD-SNAPSHOT"
# Spring Cloud Contract Stub Runner properties
STUBRUNNER_PORT="8083"
# Stub coordinates 'groupId:artifactId:version:classifier:port'
STUBRUNNER_IDS="com.example:fraud-detection:0.0.1-SNAPSHOT:stubs:9876"
# Run the docker with Stub Runner Boot
docker run  --rm -e "STUBRUNNER_IDS=${STUBRUNNER_IDS}" -e "STUBRUNNER_WORK_OFFLINE=true" -p "${STUBRUNNER_PORT}:${STUBRUNNER_PORT}" -p "9876:9876"  -v "${HOME}/.m2/:/root/.m2:ro" springcloud/spring-cloud-contract-stub-runner:"${SC_CONTRACT_DOCKER_VERSION}"

or use Spring Cloud CLI

$ spring cloud stubrunner

You will get sth like this
```
["marcin","josh"]
```

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README.adoc

README.adoc

Spring Cloud Contract Car Rental

car-rental (consumer)

fraud-detection (producer)

Presentation steps

Before

Start.spring.io

car-rental

fraud-detection

Code

HTTP

Messaging

REST Docs

Discovery

Stub Runner Boot with Eureka and Rabbit (optional)

Stub Runner Boot with a NodeJs app

Files

README.adoc

Latest commit

History

README.adoc

File metadata and controls

Spring Cloud Contract Car Rental

car-rental (consumer)

fraud-detection (producer)

Presentation steps

Before

Start.spring.io

car-rental

fraud-detection

Code

HTTP

Messaging

REST Docs

Discovery

Stub Runner Boot with Eureka and Rabbit (optional)

Stub Runner Boot with a NodeJs app