4. Spring Cloud Contract Verifier Setup

In order to use Spring Cloud Contract Verifier with WireMock, you muse use either a Gradle or a Maven plugin.

	Warning
	If you want to use Spock in your projects, you must add separately the spock-core and spock-spring modules. Check Spock docs for more information

To add a Gradle plugin with dependencies, use code similar to this:

buildscript {
	repositories {
		mavenCentral()
	}
	dependencies {
	    classpath "org.springframework.boot:spring-boot-gradle-plugin:${springboot_version}"
		classpath "org.springframework.cloud:spring-cloud-contract-gradle-plugin:${verifier_version}"
	}
}

apply plugin: 'groovy'
apply plugin: 'spring-cloud-contract'

dependencyManagement {
	imports {
		mavenBom "org.springframework.cloud:spring-cloud-contract-dependencies:${verifier_version}"
	}
}

dependencies {
	testCompile 'org.codehaus.groovy:groovy-all:2.4.6'
	// example with adding Spock core and Spock Spring
	testCompile 'org.spockframework:spock-core:1.0-groovy-2.4'
	testCompile 'org.spockframework:spock-spring:1.0-groovy-2.4'
	testCompile 'org.springframework.cloud:spring-cloud-starter-contract-verifier'
}

By default, Rest Assured 3.x is added to the classpath. However, to use Rest Assured 2.x you can add it to the plugins classpath, as shown here:

buildscript {
	repositories {
		mavenCentral()
	}
	dependencies {
	    classpath "org.springframework.boot:spring-boot-gradle-plugin:${springboot_version}"
		classpath "org.springframework.cloud:spring-cloud-contract-gradle-plugin:${verifier_version}"
		classpath "com.jayway.restassured:rest-assured:2.5.0"
		classpath "com.jayway.restassured:spring-mock-mvc:2.5.0"
	}
}

depenendencies {
    // all dependencies
    // you can exclude rest-assured from spring-cloud-contract-verifier
    testCompile "com.jayway.restassured:rest-assured:2.5.0"
    testCompile "com.jayway.restassured:spring-mock-mvc:2.5.0"
}

That way, the plugin automatically sees that Rest Assured 2.x is present on the classpath and modifies the imports accordingly.

Add the additional snapshot repository to your build.gradle to use snapshot versions, which are automatically uploaded after every successful build, as shown here:

buildscript {
	repositories {
		mavenCentral()
		mavenLocal()
		maven { url "https://repo.spring.io/snapshot" }
		maven { url "https://repo.spring.io/milestone" }
		maven { url "https://repo.spring.io/release" }
	}
}

By default, Spring Cloud Contract Verifier is looking for stubs in the src/test/resources/contracts directory.

The directory containing stub definitions is treated as a class name, and each stub definition is treated as a single test. Spring Cloud Contract Verifier assumes that it contains at least one level of directories that are to be used as the test class name. If more than one level of nested directories is present, all except the last one is used as the package name. For example, with following structure:

src/test/resources/contracts/myservice/shouldCreateUser.groovy
src/test/resources/contracts/myservice/shouldReturnUser.groovy

Spring Cloud Contract Verifier creates a test class named defaultBasePackage.MyService with two methods:

The plugin registers itself to be invoked before a check task. If you want it to be part of your build process, you need to do nothing more. If you just want to generate tests, invoke the generateContractTests task.

The default Gradle Plugin setup creates the following Gradle part of the build (in pseudocode):

contracts {
    targetFramework = 'JUNIT'
    testMode = 'MockMvc'
    generatedTestSourcesDir = project.file("${project.buildDir}/generated-test-sources/contracts")
    contractsDslDir = "${project.rootDir}/src/test/resources/contracts"
    basePackageForTests = 'org.springframework.cloud.verifier.tests'
    stubsOutputDir = project.file("${project.buildDir}/stubs")

    // the following properties are used when you want to provide where the JAR with contract lays
    contractDependency {
        stringNotation = ''
    }
    contractsPath = ''
    contractsWorkOffline = false
    contractRepository {
        cacheDownloadedContracts(true)
    }
}

tasks.create(type: Jar, name: 'verifierStubsJar', dependsOn: 'generateClientStubs') {
    baseName = project.name
    classifier = contracts.stubsSuffix
    from contractVerifier.stubsOutputDir
}

project.artifacts {
    archives task
}

tasks.create(type: Copy, name: 'copyContracts') {
    from contracts.contractsDslDir
    into contracts.stubsOutputDir
}

verifierStubsJar.dependsOn 'copyContracts'

publishing {
    publications {
        stubs(MavenPublication) {
            artifactId project.name
            artifact verifierStubsJar
        }
    }
}

To change the default configuration, add a contracts snippet to your Gradle config, as shown here:

contracts {
	testMode = 'MockMvc'
	baseClassForTests = 'org.mycompany.tests'
	generatedTestSourcesDir = project.file('src/generatedContract')
}

The following properties are used when you want to specify the location of the JAR containing the contracts: * contractDependency: Specifies the Dependency that provides groupid:artifactid:version:classifier coordinates. You can use the contractDependency closure to set it up. * contractsPath: Specifies the path to the jar. If contract dependencies are downloaded, the path defaults to groupid/artifactid where groupid is slash separated. Otherwise, it scans contracts under the provided directory. * contractsMode: Specifies the mode of downloading contracts (whether the JAR is available offline, remotely etc.) * contractsSnapshotCheckSkip: If set to true will not assert whether the downloaded stubs / contract JAR was downloaded from a remote location or a local one(only applicable to Maven repos, not Git or Pact). * deleteStubsAfterTest: If set to false will not remove any downloaded contracts from temporary directories

When using Spring Cloud Contract Verifier in default MockMvc, you need to create a base specification for all generated acceptance tests. In this class, you need to point to an endpoint, which should be verified.

abstract class BaseMockMvcSpec extends Specification {

	def setup() {
		RestAssuredMockMvc.standaloneSetup(new PairIdController())
	}

	void isProperCorrelationId(Integer correlationId) {
		assert correlationId == 123456
	}

	void isEmpty(String value) {
		assert value == null
	}

}

If you use Explicit mode, you can use a base class to initialize the whole tested app as you might see in regular integration tests. If you use the JAXRSCLIENT mode, this base class should also contain a protected WebTarget webTarget field. Right now, the only option to test the JAX-RS API is to start a web server.

If your base classes differ between contracts, you can tell the Spring Cloud Contract plugin which class should get extended by the autogenerated tests. You have two options:

By Convention

The convention is such that if you have a contract under (for example) src/test/resources/contract/foo/bar/baz/ and set the value of the packageWithBaseClasses property to com.example.base, then Spring Cloud Contract Verifier assumes that there is a BarBazBase class under the com.example.base package. In other words, the system takes the last two parts of the package, if they exist, and forms a class with a Base suffix. This rule takes precedence over baseClassForTests. Here is an example of how it works in the contracts closure:

packageWithBaseClasses = 'com.example.base'

By Mapping

You can manually map a regular expression of the contract’s package to fully qualified name of the base class for the matched contract. You have to provide a list called baseClassMappings that consists baseClassMapping objects that takes a contractPackageRegex to baseClassFQN mapping. Consider the following example:

baseClassForTests = "com.example.FooBase"
baseClassMappings {
	baseClassMapping('.*/com/.*', 'com.example.ComBase')
	baseClassMapping('.*/bar/.*':'com.example.BarBase')
}

Let’s assume that you have contracts under - src/test/resources/contract/com/ - src/test/resources/contract/foo/

By providing the baseClassForTests, we have a fallback in case mapping did not succeed. (You could also provide the packageWithBaseClasses as a fallback.) That way, the tests generated from src/test/resources/contract/com/ contracts extend the com.example.ComBase, whereas the rest of the tests extend com.example.FooBase.

To ensure that the provider side is compliant with defined contracts, you need to invoke:

./gradlew generateContractTests test

If you’re using the SCM repository to keep the contracts and stubs, you might want to automate the step of pushing stubs to the repository. To do that, it’s enough to call the pushStubsToScm task. Example:

$ ./gradlew pushStubsToScm

Under Section 10.6, “Using the SCM Stub Downloader” you can find all possible configuration options that you can pass either via the contractsProperties field e.g. contracts { contractsProperties = [foo:"bar"] }, via contractsProperties method e.g. contracts { contractsProperties([foo:"bar"]) }, a system property or an environment variable.

In a consuming service, you need to configure the Spring Cloud Contract Verifier plugin in exactly the same way as in case of provider. If you do not want to use Stub Runner then you need to copy contracts stored in src/test/resources/contracts and generate WireMock JSON stubs using:

./gradlew generateClientStubs

	Note
	The stubsOutputDir option has to be set for stub generation to work.

When present, JSON stubs can be used in automated tests of consuming a service.

@ContextConfiguration(loader == SpringApplicationContextLoader, classes == Application)
class LoanApplicationServiceSpec extends Specification {

 @ClassRule
 @Shared
 WireMockClassRule wireMockRule == new WireMockClassRule()

 @Autowired
 LoanApplicationService sut

 def 'should successfully apply for loan'() {
   given:
 	LoanApplication application =
			new LoanApplication(client: new Client(clientPesel: '12345678901'), amount: 123.123)
   when:
	LoanApplicationResult loanApplication == sut.loanApplication(application)
   then:
	loanApplication.loanApplicationStatus == LoanApplicationStatus.LOAN_APPLIED
	loanApplication.rejectionReason == null
 }
}

LoanApplication makes a call to FraudDetection service. This request is handled by a WireMock server configured with stubs generated by Spring Cloud Contract Verifier.

Add the Spring Cloud Contract BOM in a fashion similar to this:

<dependencyManagement>
	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-dependencies</artifactId>
			<version>${spring-cloud-release.version}</version>
			<type>pom</type>
			<scope>import</scope>
		</dependency>
	</dependencies>
</dependencyManagement>

Next, add the Spring Cloud Contract Verifier Maven plugin:

<plugin>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-contract-maven-plugin</artifactId>
	<version>${spring-cloud-contract.version}</version>
	<extensions>true</extensions>
	<configuration>
		<packageWithBaseClasses>com.example.fraud</packageWithBaseClasses>
	</configuration>
</plugin>

You can read more in the Spring Cloud Contract Maven Plugin Documentation (example for 2.0.0.RELEASE version).

By default, Rest Assured 3.x is added to the classpath. However, you can use Rest Assured 2.x by adding it to the plugins classpath, as shown here:

<plugin>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
    <version>${spring-cloud-contract.version}</version>
    <extensions>true</extensions>
    <configuration>
        <packageWithBaseClasses>com.example</packageWithBaseClasses>
    </configuration>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-contract-verifier</artifactId>
            <version>${spring-cloud-contract.version}</version>
        </dependency>
        <dependency>
           <groupId>com.jayway.restassured</groupId>
           <artifactId>rest-assured</artifactId>
           <version>2.5.0</version>
           <scope>compile</scope>
        </dependency>
        <dependency>
           <groupId>com.jayway.restassured</groupId>
           <artifactId>spring-mock-mvc</artifactId>
           <version>2.5.0</version>
           <scope>compile</scope>
        </dependency>
    </dependencies>
</plugin>

<dependencies>
    <!-- all dependencies -->
    <!-- you can exclude rest-assured from spring-cloud-contract-verifier -->
    <dependency>
       <groupId>com.jayway.restassured</groupId>
       <artifactId>rest-assured</artifactId>
       <version>2.5.0</version>
       <scope>test</scope>
    </dependency>
    <dependency>
       <groupId>com.jayway.restassured</groupId>
       <artifactId>spring-mock-mvc</artifactId>
       <version>2.5.0</version>
       <scope>test</scope>
    </dependency>
</dependencies>

That way, the plugin automatically sees that Rest Assured 3.x is present on the classpath and modifies the imports accordingly.

For Snapshot and Milestone versions, you have to add the following section to your pom.xml, as shown here:

<repositories>
	<repository>
		<id>spring-snapshots</id>
		<name>Spring Snapshots</name>
		<url>https://repo.spring.io/snapshot</url>
		<snapshots>
			<enabled>true</enabled>
		</snapshots>
	</repository>
	<repository>
		<id>spring-milestones</id>
		<name>Spring Milestones</name>
		<url>https://repo.spring.io/milestone</url>
		<snapshots>
			<enabled>false</enabled>
		</snapshots>
	</repository>
	<repository>
		<id>spring-releases</id>
		<name>Spring Releases</name>
		<url>https://repo.spring.io/release</url>
		<snapshots>
			<enabled>false</enabled>
		</snapshots>
	</repository>
</repositories>
<pluginRepositories>
	<pluginRepository>
		<id>spring-snapshots</id>
		<name>Spring Snapshots</name>
		<url>https://repo.spring.io/snapshot</url>
		<snapshots>
			<enabled>true</enabled>
		</snapshots>
	</pluginRepository>
	<pluginRepository>
		<id>spring-milestones</id>
		<name>Spring Milestones</name>
		<url>https://repo.spring.io/milestone</url>
		<snapshots>
			<enabled>false</enabled>
		</snapshots>
	</pluginRepository>
	<pluginRepository>
		<id>spring-releases</id>
		<name>Spring Releases</name>
		<url>https://repo.spring.io/release</url>
		<snapshots>
			<enabled>false</enabled>
		</snapshots>
	</pluginRepository>
</pluginRepositories>

By default, Spring Cloud Contract Verifier is looking for stubs in the src/test/resources/contracts directory. The directory containing stub definitions is treated as a class name, and each stub definition is treated as a single test. We assume that it contains at least one directory to be used as test class name. If there is more than one level of nested directories, all except the last one is used as package name. For example, with following structure:

src/test/resources/contracts/myservice/shouldCreateUser.groovy
src/test/resources/contracts/myservice/shouldReturnUser.groovy

Spring Cloud Contract Verifier creates a test class named defaultBasePackage.MyService with two methods

The plugin goal generateTests is assigned to be invoked in the phase called generate-test-sources. If you want it to be part of your build process, you need not do anything. If you just want to generate tests, invoke the generateTests goal.

To change the default configuration, just add a configuration section to the plugin definition or the execution definition, as shown here:

<plugin>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>convert</goal>
                <goal>generateStubs</goal>
                <goal>generateTests</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <basePackageForTests>org.springframework.cloud.verifier.twitter.place</basePackageForTests>
        <baseClassForTests>org.springframework.cloud.verifier.twitter.place.BaseMockMvcSpec</baseClassForTests>
    </configuration>
</plugin>

If you want to download your contract definitions from a Maven repository, you can use the following options:

We cache only non-snapshot, explicitly provided versions (for example + or 1.0.0.BUILD-SNAPSHOT won’t get cached). By default, this feature is turned on.

When using Spring Cloud Contract Verifier in default MockMvc, you need to create a base specification for all generated acceptance tests. In this class, you need to point to an endpoint, which should be verified.

package org.mycompany.tests

import org.mycompany.ExampleSpringController
import com.jayway.restassured.module.mockmvc.RestAssuredMockMvc
import spock.lang.Specification

class MvcSpec extends Specification {
  def setup() {
   RestAssuredMockMvc.standaloneSetup(new ExampleSpringController())
  }
}

You can also setup the whole context if necessary.

import io.restassured.module.mockmvc.RestAssuredMockMvc;
import org.junit.Before;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.web.context.WebApplicationContext;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT, classes = SomeConfig.class, properties="some=property")
public abstract class BaseTestClass {

	@Autowired
	WebApplicationContext context;

	@Before
	public void setup() {
		RestAssuredMockMvc.webAppContextSetup(this.context);
	}
}

If you use EXPLICIT mode, you can use a base class to initialize the whole tested app similarly, as you might find in regular integration tests.

import io.restassured.RestAssured;
import org.junit.Before;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.web.server.LocalServerPort
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.web.context.WebApplicationContext;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT, classes = SomeConfig.class, properties="some=property")
public abstract class BaseTestClass {

	@LocalServerPort
	int port;

	@Before
	public void setup() {
		RestAssured.baseURI = "http://localhost:" + this.port;
	}
}

If you use the JAXRSCLIENT mode, this base class should also contain a protected WebTarget webTarget field. Right now, the only option to test the JAX-RS API is to start a web server.

If your base classes differ between contracts, you can tell the Spring Cloud Contract plugin which class should get extended by the autogenerated tests. You have two options:

By Convention

The convention is such that if you have a contract under (for example) src/test/resources/contract/foo/bar/baz/ and set the value of the packageWithBaseClasses property to com.example.base, then Spring Cloud Contract Verifier assumes that there is a BarBazBase class under the com.example.base package. In other words, the system takes the last two parts of the package, if they exist, and forms a class with a Base suffix. This rule takes precedence over baseClassForTests. Here is an example of how it works in the contracts closure:

<plugin>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-contract-maven-plugin</artifactId>
	<configuration>
		<packageWithBaseClasses>hello</packageWithBaseClasses>
	</configuration>
</plugin>

By Mapping

You can manually map a regular expression of the contract’s package to fully qualified name of the base class for the matched contract. You have to provide a list called baseClassMappings that consists baseClassMapping objects that takes a contractPackageRegex to baseClassFQN mapping. Consider the following example:

<plugin>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-contract-maven-plugin</artifactId>
	<configuration>
		<baseClassForTests>com.example.FooBase</baseClassForTests>
		<baseClassMappings>
			<baseClassMapping>
				<contractPackageRegex>.*com.*</contractPackageRegex>
				<baseClassFQN>com.example.TestBase</baseClassFQN>
			</baseClassMapping>
		</baseClassMappings>
	</configuration>
</plugin>

Assume that you have contracts under these two locations: * src/test/resources/contract/com/ * src/test/resources/contract/foo/

By providing the baseClassForTests, we have a fallback in case mapping did not succeed. (You can also provide the packageWithBaseClasses as a fallback.) That way, the tests generated from src/test/resources/contract/com/ contracts extend the com.example.ComBase, whereas the rest of the tests extend com.example.FooBase.

The Spring Cloud Contract Maven Plugin generates verification code in a directory called /generated-test-sources/contractVerifier and attaches this directory to testCompile goal.

For Groovy Spock code, use the following:

<plugin>
	<groupId>org.codehaus.gmavenplus</groupId>
	<artifactId>gmavenplus-plugin</artifactId>
	<version>1.5</version>
	<executions>
		<execution>
			<goals>
				<goal>testCompile</goal>
			</goals>
		</execution>
	</executions>
	<configuration>
		<testSources>
			<testSource>
				<directory>${project.basedir}/src/test/groovy</directory>
				<includes>
					<include>**/*.groovy</include>
				</includes>
			</testSource>
			<testSource>
				<directory>${project.build.directory}/generated-test-sources/contractVerifier</directory>
				<includes>
					<include>**/*.groovy</include>
				</includes>
			</testSource>
		</testSources>
	</configuration>
</plugin>

To ensure that provider side is compliant with defined contracts, you need to invoke mvn generateTest test.

If you’re using the SCM repository to keep the contracts and stubs, you might want to automate the step of pushing stubs to the repository. To do that, it’s enough to add the pushStubsToScm goal. Example:

<plugin>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
    <version>${spring-cloud-contract.version}</version>
    <extensions>true</extensions>
    <configuration>
        <!-- Base class mappings etc. -->

        <!-- We want to pick contracts from a Git repository -->
        <contractsRepositoryUrl>git://https://github.com/spring-cloud-samples/spring-cloud-contract-nodejs-contracts-git.git</contractsRepositoryUrl>

        <!-- We reuse the contract dependency section to set up the path
        to the folder that contains the contract definitions. In our case the
        path will be /groupId/artifactId/version/contracts -->
        <contractDependency>
            <groupId>${project.groupId}</groupId>
            <artifactId>${project.artifactId}</artifactId>
            <version>${project.version}</version>
        </contractDependency>

        <!-- The contracts mode can't be classpath -->
        <contractsMode>REMOTE</contractsMode>
    </configuration>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <!-- By default we will not push the stubs back to SCM,
                you have to explicitly add it as a goal -->
                <goal>pushStubsToScm</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Under Section 10.6, “Using the SCM Stub Downloader” you can find all possible configuration options that you can pass either via the <configuration><contractProperties> map, a system property or an environment variable.

If you see the following exception while using STS:

When you click on the error marker you should see something like this:

 plugin:1.1.0.M1:convert:default-convert:process-test-resources) org.apache.maven.plugin.PluginExecutionException: Execution default-convert of goal org.springframework.cloud:spring-
 cloud-contract-maven-plugin:1.1.0.M1:convert failed. at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:145) at
 org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:331) at org.eclipse.m2e.core.internal.embedder.MavenImpl$11.call(MavenImpl.java:1362) at
...
 org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) Caused by: java.lang.NullPointerException at
 org.eclipse.m2e.core.internal.builder.plexusbuildapi.EclipseIncrementalBuildContext.hasDelta(EclipseIncrementalBuildContext.java:53) at
 org.sonatype.plexus.build.incremental.ThreadBuildContext.hasDelta(ThreadBuildContext.java:59) at

In order to fix this issue, provide the following section in your pom.xml:

<build>
    <pluginManagement>
        <plugins>
            <!--This plugin's configuration is used to store Eclipse m2e settings
                only. It has no influence on the Maven build itself. -->
            <plugin>
                <groupId>org.eclipse.m2e</groupId>
                <artifactId>lifecycle-mapping</artifactId>
                <version>1.0.0</version>
                <configuration>
                    <lifecycleMappingMetadata>
                        <pluginExecutions>
                             <pluginExecution>
                                <pluginExecutionFilter>
                                    <groupId>org.springframework.cloud</groupId>
                                    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
                                    <versionRange>[1.0,)</versionRange>
                                    <goals>
                                        <goal>convert</goal>
                                    </goals>
                                </pluginExecutionFilter>
                                <action>
                                    <execute />
                                </action>
                             </pluginExecution>
                        </pluginExecutions>
                    </lifecycleMappingMetadata>
                </configuration>
            </plugin>
        </plugins>
    </pluginManagement>
</build>

Since the Docker image can be used by non JVM projects, it’s good to explain the basic terms behind Spring Cloud Contract packaging defaults.

Part of the following definitions were taken from the Maven Glossary

The image searches for contracts under the /contracts folder. The output from running the tests will be available under /spring-cloud-contract/build folder (it’s useful for debugging purposes).

It’s enough for you to mount your contracts, pass the environment variables and the image will:

Let’s take a look at a simple MVC application

$ git clone https://github.com/spring-cloud-samples/spring-cloud-contract-nodejs
$ cd bookstore

The contracts are available under /contracts folder.

Since we want to run tests, we could just execute:

$ npm test

however, for learning purposes, let’s split it into pieces:

# Stop docker infra (nodejs, artifactory)
$ ./stop_infra.sh
# Start docker infra (nodejs, artifactory)
$ ./setup_infra.sh

# Kill & Run app
$ pkill -f "node app"
$ nohup node app &

# Prepare environment variables
$ SC_CONTRACT_DOCKER_VERSION="..."
$ APP_IP="192.168.0.100"
$ APP_PORT="3000"
$ ARTIFACTORY_PORT="8081"
$ APPLICATION_BASE_URL="http://${APP_IP}:${APP_PORT}"
$ ARTIFACTORY_URL="http://${APP_IP}:${ARTIFACTORY_PORT}/artifactory/libs-release-local"
$ CURRENT_DIR="$( pwd )"
$ CURRENT_FOLDER_NAME=${PWD##*/}
$ PROJECT_VERSION="0.0.1.RELEASE"

# Execute contract tests
$ docker run  --rm -e "APPLICATION_BASE_URL=${APPLICATION_BASE_URL}" -e "PUBLISH_ARTIFACTS=true" -e "PROJECT_NAME=${CURRENT_FOLDER_NAME}" -e "REPO_WITH_BINARIES_URL=${ARTIFACTORY_URL}" -e "PROJECT_VERSION=${PROJECT_VERSION}" -v "${CURRENT_DIR}/contracts/:/contracts:ro" -v "${CURRENT_DIR}/node_modules/spring-cloud-contract/output:/spring-cloud-contract-output/" springcloud/spring-cloud-contract:"${SC_CONTRACT_DOCKER_VERSION}"

# Kill app
$ pkill -f "node app"

What will happen is that via bash scripts:

To see how the client side looks like check out the Section 6.9, “Stub Runner Docker” section.