Docker Project

在本节中,我们发布 springcloud/spring-cloud-contract Docker 镜像,其中包含一个项目,该项目生成测试,并在 EXPLICIT 模式下针对正在运行的应用程序运行这些测试。

In this section, we publish a springcloud/spring-cloud-contract Docker image that contains a project that generates tests and runs them in EXPLICIT mode against a running application.

`EXPLICIT`模式意味着从合同生成的测试发送真实的请求,而不是模拟的请求。

The EXPLICIT mode means that the tests generated from contracts send real requests and not mocked ones.

我们还发布 spring-cloud/spring-cloud-contract-stub-runner Docker 镜像,它启动 Stub Runner 的独立版本。

We also publish a spring-cloud/spring-cloud-contract-stub-runner Docker image that starts the standalone version of Stub Runner.

A Short Introduction to Maven, JARs, and Binary Storage

由于非 JVM 项目可以使用 Docker 镜像,因此最好解释 Spring Cloud Contract 默认打包方式背后的基本概念。

Since non-JVM projects can use the Docker image, it is good to explain the basic terms behind Spring Cloud Contract packaging defaults.

下列部分的定义取自 Maven Glossary

Parts of the following definitions were taken from the Maven Glossary:

  • Project: Maven thinks in terms of projects. Projects are all you build. Those projects follow a well defined “Project Object Model”. Projects can depend on other projects — in that case, the latter are called “dependencies”. A project may consistent of several subprojects. However, these subprojects are still treated equally as projects.

  • Artifact: An artifact is something that is either produced or used by a project. Examples of artifacts produced by Maven for a project include JAR files and source and binary distributions. Each artifact is uniquely identified by a group ID and an artifact ID that is unique within a group.

  • JAR: JAR stands for Java ARchive. Its format is based on the ZIP file format. Spring Cloud Contract packages the contracts and generated stubs in a JAR file.

  • GroupId: A group ID is a universally unique identifier for a project. While this is often just the project name (for example, commons-collections), it is helpful to use a fully-qualified package name to distinguish it from other projects with a similar name (for example, org.apache.maven). Typically, when published to the Artifact Manager, the GroupId gets slash separated and forms part of the URL. For example, for a group ID of com.example and an artifact ID of application, the result would be /com/example/application/.

  • Classifier: The Maven dependency notation looks as follows: groupId:artifactId:version:classifier. The classifier is an additional suffix passed to the dependency — for example, stubs or sources. The same dependency (for example, com.example:application) can produce multiple artifacts that differ from each other with the classifier.

  • Artifact manager: When you generate binaries, sources, or packages, you would like them to be available for others to download, reference, or reuse. In the case of the JVM world, those artifacts are generally JARs. For Ruby, those artifacts are gems. For Docker, those artifacts are Docker images. You can store those artifacts in a manager. Examples of such managers include Artifactory and Nexus.

Generating Tests on the Producer Side

镜像在 /contracts 文件夹下搜索合约。测试运行结果可在 /spring-cloud-contract/build 文件夹中找到(这对调试很有用)。

The image searches for contracts under the /contracts folder. The output from running the tests is available in the /spring-cloud-contract/build folder (useful for debugging purposes).

您可以挂载合约并传递环境变量。然后镜像会执行以下操作:

You can mount your contracts and pass the environment variables. The image then:

  • Generates the contract tests

  • Runs the tests against the provided URL

  • Generates the WireMock stubs

  • Publishes the stubs to a Artifact Manager (optional — turned on by default)

Environment Variables

Docker 镜像要求一些环境变量指向您正在运行的应用程序、构件管理器实例等。以下列表描述了环境变量:

The Docker image requires some environment variables to point to your running application, to the Artifact manager instance, and so on. The following list describes the environment variables:

Table 1. Docker environment variables

Name

Description

Default

ADDITIONAL_FLAGS

(Docker Image only) Additional flags to be passed to the Gradle build

DEBUG

(Docker Image only) Applicable for Docker Image - turns on debug mode for the Gradle build

false

EXTERNAL_CONTRACTS_ARTIFACT_ID

Artifact ID of the project with contracts

EXTERNAL_CONTRACTS_CLASSIFIER

Classifier of the project with contracts

EXTERNAL_CONTRACTS_GROUP_ID

Group ID of the project with contracts

com.example

EXTERNAL_CONTRACTS_PATH

Path to contracts for the given project, inside the project with contracts. Defaults to slash-separated EXTERNAL_CONTRACTS_GROUP_ID concatenated with / and EXTERNAL_CONTRACTS_ARTIFACT_ID. For example, for group id `cat-server-side.dog and artifact ID fish, would result in cat/dog/fish for the contracts path.

EXTERNAL_CONTRACTS_REPO_WITH_BINARIES_PASSWORD

(optional) Password if the EXTERNAL_CONTRACTS_REPO_WITH_BINARIES_URL requires authentication. It defaults to `REPO_WITH_BINARIES_PASSWORD, If that is not set, it defaults to `password

EXTERNAL_CONTRACTS_REPO_WITH_BINARIES_URL

URL of your Artifact Manager. It defaults to the value of REPO_WITH_BINARIES_URL environment variable and if that is not set, it defaults to http://localhost:8081/artifactory/libs-release-local

EXTERNAL_CONTRACTS_REPO_WITH_BINARIES_USERNAME

(optional) Username if the EXTERNAL_CONTRACTS_REPO_WITH_BINARIES_URL requires authentication. It defaults to REPO_WITH_BINARIES_USERNAME. If that is not set, it defaults to `admin

EXTERNAL_CONTRACTS_VERSION

Version of the project with contracts. Defautls to an equivalent of picking the latest

+

EXTERNAL_CONTRACTS_WORK_OFFLINE

If set to true, retrieves the artifact with contracts from the container’s .m2. Mount your local .m2 as a volume available at the container’s /root/.m2 path

false

FAIL_ON_NO_CONTRACTS

Should the build fail if there are no contracts present?

false

MESSAGING_TYPE

Type of messaging. Can be either [rabbit] or [kafka].

PRODUCER_STUBS_CLASSIFIER

Archive classifier used for generated producer stubs

stubs

PROJECT_GROUP

Your project’s group ID

com.example

PROJECT_NAME

Your project’s artifact id

example

PROJECT_VERSION

Your project’s version

0.0.1-SNAPSHOT

PUBLISH_ARTIFACTS

If set to true, publishes the artifact to binary storage

true

PUBLISH_ARTIFACTS_OFFLINE

If set to true, publishes the artifacts to local m2

false

PUBLISH_STUBS_TO_SCM

If set to true will run the task to publish stubs to scm

false

REPO_ALLOW_INSECURE_PROTOCOL

(optional) If <true> allows to publish artifacts to Artifact Manager over insecure HTTP

false

REPO_WITH_BINARIES_PASSWORD

(optional) Password when the Artifact Manager is secured

password

REPO_WITH_BINARIES_URL

URL of your Artifact Manager (defaults to the default URL of Artifactory when running locally)

[role="bare"]http://localhost:8081/artifactory/libs-release-local

REPO_WITH_BINARIES_USERNAME

(optional) Username when the Artifact Manager is secured

admin

STANDALONE_PROTOCOL

For standalone version, which additional protocol should be added

在运行测试时使用以下环境变量:

The following environment variables are used when tests are run:

本文概述了用于连接到应用程序以触发消息的配置设置。它定义了必需的配置参数,如连接和读取超时以及消息传递类型,并提供了每种配置的示例值。这些设置允许应用程序集成到消息传递系统中,以实现事件驱动的通信。

Table 2. Docker environment variables - read at runtime

Name

Description

Default

APPLICATION_BASE_URL

URL at which the application is running.

APPLICATION_PASSWORD

Optional password to access the application.

APPLICATION_USERNAME

Optional username to access the application.

MESSAGING_TRIGGER_CONNECT_TIMEOUT

Timeout to connect to the application to trigger a message.

5000

MESSAGING_TRIGGER_READ_TIMEOUT

Timeout to read the response from the application to trigger a message.

5000

MESSAGING_TYPE

Defines the messaging type when dealing with message based contracts.

MESSAGING_TYPE

Type of messaging. Can be either [rabbit] or [kafka].

SPRING_KAFKA_BOOTSTRAP_SERVERS

For Kafka - brokers addresses.

SPRING_RABBITMQ_ADDRESSES

For RabbitMQ - brokers addresses.

Customizing the gradle build

通过在运行容器时将自定义构建文件挂载为卷,您可以提供一个定制的 gradle.build 在容器中运行:

You can provide a customized gradle.build to be run in the container by mounting your customized build file as a volume when running the container:

$ docker run -v <absolute-path-of-your-custom-file>:/spring-cloud-contract/build.gradle springcloud/spring-cloud-contract:<version>

Example of Usage via HTTP

本节中,我们将探讨一个简单的 MVC 应用。为了开始,请克隆以下 git 存储库,并通过运行以下命令 cd 到结果目录:

In this section, we explore a simple MVC application. To get started, clone the following git repository and cd to the resulting directory, by running the following commands:

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

合同在 /contracts 文件夹中。

The contracts are available in the /contracts folder.

由于我们要运行测试,因此,我们可以运行以下命令:

Since we want to run tests, we can run the following command:

$ npm test

但是,出于学习目的,我们将它分成如下部分:

However, for learning purposes, we split it into pieces, as follows:

# 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"

# Run 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"

通过 bash 脚本,将发生以下情况:

Through bash scripts, the following happens:

  • The infrastructure (MongoDb and Artifactory) is set up. In a real-life scenario, you would run the NodeJS application with a mocked database. In this example, we want to show how we can benefit from Spring Cloud Contract in very little time.

  • Due to those constraints, the contracts also represent the stateful situation.

    • The first request is a POST that causes data to get inserted into the database.

    • The second request is a GET that returns a list of data with 1 previously inserted element.

  • The NodeJS application is started (on port 3000).

  • The contract tests are generated through Docker, and tests are run against the running application.

    • The contracts are taken from /contracts folder.

    • The output of the test is available under node_modules/spring-cloud-contract/output.

  • The stubs are uploaded to Artifactory. You can find them in [role="bare"]http://localhost:8081/artifactory/libs-release-local/com/example/bookstore/0.0.1.RELEASE/. The stubs are at [role="bare"]http://localhost:8081/artifactory/libs-release-local/com/example/bookstore/0.0.1.RELEASE/bookstore-0.0.1.RELEASE-stubs.jar.

Example of Usage via Messaging

如果您想通过Docker 镜像 (例如,对于混合语言应用程序) 将 Spring Cloud Contract 与消息传递一起使用,那么您必须满足以下先决条件:

If you want to use Spring Cloud Contract with messaging via the Docker images (e.g. in case of polyglot applications) then you’ll have to have the following prerequisites met:

  • Middleware (e.g. RabbitMQ or Kafka) must be running before generating tests

  • Your contract needs to call a method triggerMessage(…​) with a String parameter that is equal to the contract’s label.

  • Your application needs to have a HTTP endpoint via which we can trigger a message

    • That endpoint should not be available on production (could be enabled via an environment variable)

Example of a Messaging Contract

合同需要调用 triggerMessage(…​) 方法。对于 Docker 镜像中所有测试的基本类中已提供了该方法,它会向生产者的 HTTP 端点发送请求。在下面您可以找到此类合同的示例。

The contract needs to call a triggerMessage(…​) method. That method is already provided in the base class for all tests in the docker image and will send out a request to the HTTP endpoint on the producer side. Below you can find examples of such contracts.

  • Groovy

  • YAML

import org.springframework.cloud.contract.spec.Contract

Contract.make {
    description 'Send a pong message in response to a ping message'
    label 'ping_pong'
    input {
        // You have to provide the `triggerMessage` method with the `label`
        // as a String parameter of the method
        triggeredBy('triggerMessage("ping_pong")')
    }
    outputMessage {
        sentTo('output')
        body([
            message: 'pong'
        ])
    }
    metadata(
        [amqp:
         [
           outputMessage: [
               connectToBroker: [
                   declareQueueWithName: "queue"
               ],
                messageProperties: [
                    receivedRoutingKey: '#'
                ]
           ]
         ]
        ])
}
description: 'Send a pong message in response to a ping message'
label: 'ping_pong'
input:
    # You have to provide the `triggerMessage` method with the `label`
    # as a String parameter of the method
    triggeredBy: 'triggerMessage("ping_pong")'
outputMessage:
    sentTo: 'output'
    body:
        message: 'pong'
metadata:
    amqp:
        outputMessage:
            connectToBroker:
                declareQueueWithName: "queue"
            messageProperties:
                receivedRoutingKey: '#'

HTTP Endpoint to Trigger a Message

为什么需要开发这样的端点?Spring Cloud Contract 需要生成各种语言的代码 (正如它在 Java 中所做的那样) 以便能够触发生产代码,该代码会向代理发送消息。如果未生成此类代码,那么无论如何,我们都需要能够触发消息,而实现它的方法是提供一个用户将使用他们选择的语言准备的 HTTP 端点。

Why is there need to develop such an endpoint? Spring Cloud Contract would have to generate code in various languages (as it does in Java) to make it possible to trigger production code that sends a message to a broker. If such code is not generated then we need to be able to trigger the message anyways, and the way to do it is to provide an HTTP endpoint that the user will prepare in the language of their choosing.

端点必须具有以下配置:

The endpoint must have the following configuration:

  • URL: /springcloudcontract/{label} where label can be any text

  • Method: POST

  • Basing on the label will generate a message that will be sent to a given destination according to the contract definition

ниже представлен пример такой конечной точки. Если вы заинтересованы в предоставлении примера на своем языке, не стесняйтесь создать проблему в Spring Cloud Contract repository at Github.

Below you have an example of such an endpoint. If you’re interested in providing an example in your language don’t hesitate to file an issue in the Spring Cloud Contract repository at Github.

Python
#!/usr/bin/env python

from flask import Flask
from flask import jsonify
import pika
import os

app = Flask(__name__)

# Production code that sends a message to RabbitMQ
def send_message(cmd):
    connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
    channel = connection.channel()
    channel.basic_publish(
        exchange='output',
        routing_key='#',
        body=cmd,
        properties=pika.BasicProperties(
            delivery_mode=2,  # make message persistent
        ))
    connection.close()
    return " [x] Sent via Rabbit: %s" % cmd

# This should be ran in tests (shouldn't be publicly available)
if 'CONTRACT_TEST' in os.environ:
    @app.route('/springcloudcontract/<label>', methods=['POST'])
    def springcloudcontract(label):
        if label == "ping_pong":
            return send_message('{"message":"pong"}')
        else:
            raise ValueError('No such label expected.')

Running Message Tests on the Producer Side

现在,让我们根据合同生成测试来测试生产者端。我们将运行 bash 代码以启动带有附加合同的 Docker 镜像,但我们还将添加变量以使消息传递代码工作。在这种情况,让我们假设这些合同存储在 Git 存储库中。

Now, let’s generate tests from contracts to test the producer side. We will run bash code to start the Docker image with attached contracts, however we will also add variables for the messaging code to work. In this case let’s assume that the contracts are being stored in a Git repository.

#!/bin/bash
set -x

CURRENT_DIR="$( pwd )"

export SC_CONTRACT_DOCKER_VERSION="${SC_CONTRACT_DOCKER_VERSION:-4.0.1-SNAPSHOT}"
export APP_IP="$( ./whats_my_ip.sh )"
export APP_PORT="${APP_PORT:-8000}"
export APPLICATION_BASE_URL="http://${APP_IP}:${APP_PORT}"
export PROJECT_GROUP="${PROJECT_GROUP:-group}"
export PROJECT_NAME="${PROJECT_NAME:-application}"
export PROJECT_VERSION="${PROJECT_VERSION:-0.0.1-SNAPSHOT}"
export PRODUCER_STUBS_CLASSIFIER="${PRODUCER_STUBS_CLASSIFIER:-stubs}"
export FAIL_ON_NO_CONTRACTS="${FAIL_ON_NO_CONTRACTS:-false}"
# In our Python app we want to enable the HTTP endpoint
export CONTRACT_TEST="true"
# In the Verifier docker container we want to add support for RabbitMQ
export MESSAGING_TYPE="rabbit"

# Let's start the infrastructure (e.g. via Docker Compose)
yes | docker-compose kill || echo "Nothing running"
docker-compose up -d

echo "SC Contract Version [${SC_CONTRACT_DOCKER_VERSION}]"
echo "Application URL [${APPLICATION_BASE_URL}]"
echo "Project Version [${PROJECT_VERSION}]"

# Let's run python app
gunicorn -w 4 --bind 0.0.0.0 main:app &
APP_PID=$!

# Generate and run tests
docker run  --rm \
                --name verifier \
                # For the image to find the RabbitMQ running in another container
                -e "SPRING_RABBITMQ_ADDRESSES=${APP_IP}:5672" \
                # We need to tell the container what messaging middleware we will use
                -e "MESSAGING_TYPE=${MESSAGING_TYPE}" \
                -e "PUBLISH_STUBS_TO_SCM=false" \
                -e "PUBLISH_ARTIFACTS=false" \
                -e "APPLICATION_BASE_URL=${APPLICATION_BASE_URL}" \
                -e "PROJECT_NAME=${PROJECT_NAME}" \
                -e "PROJECT_GROUP=${PROJECT_GROUP}" \
                -e "PROJECT_VERSION=${PROJECT_VERSION}" \
                -e "EXTERNAL_CONTRACTS_REPO_WITH_BINARIES_URL=git://https://github.com/marcingrzejszczak/cdct_python_contracts.git" \
                -e "EXTERNAL_CONTRACTS_ARTIFACT_ID=${PROJECT_NAME}" \
                -e "EXTERNAL_CONTRACTS_GROUP_ID=${PROJECT_GROUP}" \
                -e "EXTERNAL_CONTRACTS_VERSION=${PROJECT_VERSION}" \
                -v "${CURRENT_DIR}/build/spring-cloud-contract/output:/spring-cloud-contract-output/" \
                springcloud/spring-cloud-contract:"${SC_CONTRACT_DOCKER_VERSION}"

kill $APP_PID

yes | docker-compose kill

将发生以下情况:

What will happen is:

  • Tests will be generated from contracts taken from Git

  • In the contract we’ve provided an entry in metadata called declareQueueWithName that will lead to creation of a queue in RabbitMQ with the given name before the request to trigger the message is sent

  • Via the triggerMessage("ping_pong") method call a POST request to the Python application to the /springcloudcontract/ping_pong endpoint will be made

  • The Python application will generate and send a ’{"message":"pong"}'` JSON via RabbitMQ to an exchange called output

  • The generated test will poll for a message sent to the output exchange

  • Once the message was received will assert its contents

在测试通过后,我们知道消息是从 Python 应用正确发送到 RabbitMQ。

After the tests have passed we know that the message was properly sent from the Python app to RabbitMQ.

Running Stubs on the Consumer Side

本节介绍如何在使用者侧使用 Docker 来获取和运行存根。

This section describes how to use Docker on the consumer side to fetch and run stubs.

我们发布了一个 spring-cloud/spring-cloud-contract-stub-runner Docker 镜像,它启动独立版本的 Stub Runner。

We publish a spring-cloud/spring-cloud-contract-stub-runner Docker image that starts the standalone version of Stub Runner.

Security

Поскольку Docker-образ Spring Cloud Contract Stub Runner использует автономную версию Stub Runner, необходимо учитывать те же соображения безопасности. Дополнительные сведения об этом вы можете прочитать в in this section of the documentation.

Since the Spring Cloud Contract Stub Runner Docker Image uses the standalone version of Stub Runner the same security considerations need to be taken. You can read more about those in this section of the documentation.

Environment Variables

Вы можете запустить Docker-образ и передать любой из common properties for JUnit and Springв виде переменных окружения. В соответствии с соглашением все буквы должны быть заглавными. Точка (.) должна быть заменена символами подчеркивания (_). Например, свойство stubrunner.repositoryRoot должно быть представлено в виде переменной окружения STUBRUNNER_REPOSITORY_ROOT.

You can run the docker image and pass any of the common properties for JUnit and Spring as environment variables. The convention is that all the letters should be upper case. The dot (.) should be replaced with underscore (_) characters. For example, the stubrunner.repositoryRoot property should be represented as a STUBRUNNER_REPOSITORY_ROOT environment variable.

除了那些变量外,您还可以设置以下变量:

In addition to those variables you can set the following ones:

  • MESSAGING_TYPE - what type of messaging system are you using (currently supported are rabbit, kafka)

  • ADDITIONAL_OPTS - any additional properties that you would like to pass to the application

Example of Usage

我们需要使用 [docker-server-side] 步骤中创建的存根。假设我们要在端口 9876 上运行存根。你可以克隆存储库并更改为以下命令中指示的目录,看到 NodeJS 代码:

We want to use the stubs created in this [docker-server-side] step. Assume that we want to run the stubs on port 9876. You can see the NodeJS code by cloning the repository and changing to the directory indicated in the following commands:

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

现在,我们可以通过运行以下命令,使用存根运行 Stub Runner 启动应用程序:

Now we can run the Stub Runner Boot application with the stubs, by running the following commands:

# Provide the Spring Cloud Contract Docker version
$ SC_CONTRACT_DOCKER_VERSION="..."
# The IP at which the app is running and Docker container can reach it
$ APP_IP="192.168.0.100"
# Spring Cloud Contract Stub Runner properties
$ STUBRUNNER_PORT="8083"
# Stub coordinates 'groupId:artifactId:version:classifier:port'
$ STUBRUNNER_IDS="com.example:bookstore:0.0.1.RELEASE:stubs:9876"
$ STUBRUNNER_REPOSITORY_ROOT="http://${APP_IP}:8081/artifactory/libs-release-local"
# Run the docker with Stub Runner Boot
$ docker run  --rm \
    -e "STUBRUNNER_IDS=${STUBRUNNER_IDS}" \
    -e "STUBRUNNER_REPOSITORY_ROOT=${STUBRUNNER_REPOSITORY_ROOT}" \
    -e "STUBRUNNER_STUBS_MODE=REMOTE" \
    -p "${STUBRUNNER_PORT}:${STUBRUNNER_PORT}" \
    -p "9876:9876" \
    springcloud/spring-cloud-contract-stub-runner:"${SC_CONTRACT_DOCKER_VERSION}"

在运行上述命令时,

When the preceding commands run,

  • A standalone Stub Runner application gets started.

  • It downloads the stub with coordinates com.example:bookstore:0.0.1.RELEASE:stubs on port 9876.

  • It gets downloads from Artifactory running at http://192.168.0.100:8081/artifactory/libs-release-local.

  • After a while, Stub Runner is running on port 8083.

  • The stubs are running at port 9876.

我们在服务器端构建了一个有状态存根。我们可以使用 curl 断言存根已经正确设置。为此,请运行以下命令:

On the server side, we built a stateful stub. We can use curl to assert that the stubs are setup properly. To do so, run the following commands:

# let's run the first request (no response is returned)
$ curl -H "Content-Type:application/json" -X POST --data '{ "title" : "Title", "genre" : "Genre", "description" : "Description", "author" : "Author", "publisher" : "Publisher", "pages" : 100, "image_url" : "https://d213dhlpdb53mu.cloudfront.net/assets/pivotal-square-logo-41418bd391196c3022f3cd9f3959b3f6d7764c47873d858583384e759c7db435.svg", "buy_url" : "https://pivotal.io" }' http://localhost:9876/api/books
# Now time for the second request
$ curl -X GET http://localhost:9876/api/books
# You will receive contents of the JSON

如果您要在主机上的本地环境中使用您已经构建的存根,则应设置`-e STUBRUNNER_STUBS_MODE=LOCAL`环境变量并挂载您本地 m2 的卷(-v "${HOME}/.m2/:/home/scc/.m2:ro")。

If you want use the stubs that you have built locally, on your host, you should set the -e STUBRUNNER_STUBS_MODE=LOCAL environment variable and mount the volume of your local m2 (-v "${HOME}/.m2/:/home/scc/.m2:ro").

Example of Usage with Messaging

要使消息传递正常工作,只需使用 kafkarabbit 值传递 MESSAGING_TYPE 环境变量即可。这会设置 Stub Runner Boot Docker 映像,其中包含连接到代理所需的依赖项。

In order to make messaging work it’s enough to pass the MESSAGING_TYPE environment variable with kafka or rabbit values. This will lead to setting up the Stub Runner Boot Docker image with dependencies required to connect to the broker.

要设置连接属性,你可以查看 Spring Cloud Stream 属性页面以设置正确的环境变量。

In order to set the connection properties you can check out Spring Cloud Stream properties page to set proper environment variables.

你将设置的最常见的属性是运行中心件的位置。如果设置属性的属性称为 spring.rabbitmq.addressesspring.kafka.bootstrap-servers,则分别应将环境变量命名为 SPRING_RABBITMQ_ADDRESSESSPRING_KAFKA_BOOTSTRAP_SERVERS

The most common property you would set is the location of the running middlewara. If a property to set it is called spring.rabbitmq.addresses or spring.kafka.bootstrap-servers then you should name the environment variable SPRING_RABBITMQ_ADDRESSES and SPRING_KAFKA_BOOTSTRAP_SERVERS respectively.

Running Contract Tests against Existing Middleware

针对现有中心件运行你的契约测试是合情合理的。一些测试框架可能会给你错误的肯定结果——在你的构建中通过测试,而在生产中通信失败。

There is legitimate reason to run your contract tests against existing middleware. Some testing frameworks might give you false positive results - the test within your build passes whereas on production the communication fails.

在 Spring Cloud Contract Docker 映像中,我们提供了一个连接到现有中间件的选项。如前面对比部分所述,我们默认支持 Kafka 和 RabbitMQ。但是,我们可以通过 Apache Camel Components 来支持其他中间件。我们来看一下以下几个用例。

In Spring Cloud Contract docker images we give an option to connect to existing middleware. As presented in previous subsections we do support Kafka and RabbitMQ out of the box. However, via Apache Camel Components we can support other middleware too. Let’s take a look at the following examples of usage.

Spring Cloud Contract Docker and running Middleware

要连接到任意中心件,我们将在契约部分中利用 standalone 元数据项。

In order to connect to arbitrary middleware, we’ll leverage the standalone metadata entry in the contract section.

description: 'Send a pong message in response to a ping message'
label: 'standalone_ping_pong' 1
input:
  triggeredBy: 'triggerMessage("ping_pong")' 2
outputMessage:
  sentTo: 'rabbitmq:output' 3
  body: 4
    message: 'pong'
metadata:
  standalone: 5
    setup: 6
      options: rabbitmq:output?queue=output&routingKey=(7)
    outputMessage: 8
      additionalOptions: routingKey=#&queue=output 9
1 Label by which we’ll be able to trigger the message via Stub Runner
2 As in the previous messaging examples we’ll need to trigger the HTTP endpoint in the running application to make it send a message according to the provided protocol
3 protocol:destination as requested by Apache Camel
4 Output message body
5 Standalone metadata entry
6 Setup part will contain information about how to prepare for running contract tests before the actual call to HTTP endpoint of the running application is made
7 Apache Camel URI to be called in the setup phase. In this case we will try to poll for a message at the output exchange and due to to having the queue=output and routingKey= a queue with name output will be set and bound to the output exchange with routing key
8 Additional options (more technical ones) to be appended to the protocol:destination from point (3) - together will be combined in the following format rabbitmq:output?routingKey=#&queue=output.

对于契约测试的通过,在我们通常在多语言环境中传递消息、运行应用程序和运行中心件的情况下,我们需要它。这一次,我们将为 Spring Cloud Contract Docker 映像设置不同的环境变量。

For the contract tests to pass we will need as usual in case of messaging in polyglot environment a running application and running middleware. This time we will have different environment variables set for the Spring Cloud Contract Docker image.

#!/bin/bash
set -x

# Setup
# Run the middleware
docker-compose up -d rabbitmq 1

# Run the python application
gunicorn -w 4 --bind 0.0.0.0 main:app & 2
APP_PID=$!

docker run  --rm \
                --name verifier \
                -e "STANDALONE_PROTOCOL=rabbitmq" \ 3
                -e "CAMEL_COMPONENT_RABBITMQ_ADDRESSES=172.18.0.1:5672" \ 4
                -e "PUBLISH_STUBS_TO_SCM=false" \
                -e "PUBLISH_ARTIFACTS=false" \
                -e "APPLICATION_BASE_URL=172.18.0.1" \
                -e "PROJECT_NAME=application" \
                -e "PROJECT_GROUP=group" \
                -e "EXTERNAL_CONTRACTS_ARTIFACT_ID=application" \
                -e "EXTERNAL_CONTRACTS_GROUP_ID=group" \
                -e "EXTERNAL_CONTRACTS_VERSION=0.0.1-SNAPSHOT" \
                -v "${CURRENT_DIR}/build/spring-cloud-contract/output:/spring-cloud-contract-output/" \
                springcloud/spring-cloud-contract:"${SC_CONTRACT_DOCKER_VERSION}"


# Teardown
kill $APP_PID
yes | docker-compose kill
1 We need to have the middleware running first
2 The application needs to be up and running
3 Via the STANDALONE_PROTOCOL environment variable we will fetch a Apache Camel Component. The artifact that we will fetch is org.apache.camel.springboot:camel-${STANDALONE_PROTOCOL}-starter. In other words STANDALONE_PROTOCOL is matching Camel’s component.
4 We’re setting addresses (we could be setting credentials) via Camel’s Spring Boot Starter mechanisms. Example for Apache Camel’s RabbitMQ Spring Boot Auto-Configuration

Stub Runner Docker and running Middleware

要针对正在运行的中心件触发存根消息,我们可以以下面的方式运行 Stub Runner Docker 映像。

In order to trigger a stub message against running middleware, we can run Stub Runner Docker image in the following manner.

用法示例

Example of usage

$ docker run \
    -e "CAMEL_COMPONENT_RABBITMQ_ADDRESSES=172.18.0.1:5672" \ 1
    -e "STUBRUNNER_IDS=group:application:0.0.1-SNAPSHOT" \ 2
    -e "STUBRUNNER_REPOSITORY_ROOT=git://https://github.com/marcingrzejszczak/cdct_python_contracts.git" \ 3
    -e ADDITIONAL_OPTS="--thin.properties.dependencies.rabbitmq=org.apache.camel.springboot:camel-rabbitmq-starter:3.4.0" \ 4
    -e "STUBRUNNER_STUBS_MODE=REMOTE" \ 5
    -v "${HOME}/.m2/:/home/scc/.m2:ro" \ 6
    -p 8750:8750 \ 7
    springcloud/spring-cloud-contract-stub-runner:3.0.4-SNAPSHOT 8
1 We’re injecting the address of RabbitMQ via Apache Camel’s Spring Boot Auto-Configuration
2 We’re telling Stub Runner which stubs to download
3 We’re providing an external location for our stubs (Git repository)
4 Via the ADDITIONAL_OPTS=--thin.properties.dependencies.XXX=GROUP:ARTIFACT:VERSION property we’re telling Stub Runner which additional dependency to fetch at runtime. In this case we want to fetch camel-rabbitmq-starter so XXX is a random string and we want to fetch org.apache.camel.springboot:camel-rabbitmq-starter artifact in version 3.4.0.
5 Since we’re using Git, the remote option of fetching stubs needs to be set
6 So that we speed up launching of Stub Runner, we’re attaching our local Maven repository .m2 as a volume. If you don’t have it populated you can consider setting the write permissions via :rw instead read only :ro.
7 We expose the port 8750 at which Stub Runner is running.
8 Coordinates of the Stub Runner Docker image.

过了一会儿,你将在控制台中看到以下文本,这意味着 Stub Runner 已经准备好接受请求。

After a while you’ll notice the following text in your console, which means that Stub Runner is ready to accept requests.

o.a.c.impl.engine.AbstractCamelContext   : Apache Camel 3.4.3 (camel-1) started in 0.007 seconds
o.s.c.c.s.server.StubRunnerBoot          : Started StubRunnerBoot in 14.483 seconds (JVM running for 18.666)
o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
o.s.web.servlet.DispatcherServlet        : Completed initialization in 2 ms

要获取触发器列表,你可以向 localhost:8750/triggers 端点发送 HTTP GET 请求。要触发存根消息,你可以向 localhost:8750/triggers/standalone_ping_pong 发送 HTTP POST 请求。在控制台中,你将看到:

To get the list of triggers you can send an HTTP GET request to localhost:8750/triggers endpoint. To trigger a stub message, you can send a HTTP POST request to localhost:8750/triggers/standalone_ping_pong. In the console you’ll see:

o.s.c.c.v.m.camel.CamelStubMessages      : Will send a message to URI [rabbitmq:output?routingKey=#&queue=output]

如果你查看 RabbitMQ 管理控制台,你将看到 output 队列中有 1 条消息可用。

If you check the RabbitMQ management console, you’ll see that there’s 1 message available in the output queue.