Maven构建服务器未部署Consul时如何测试Consul DiscoveryClient功能

你遇到的报错是测试运行时没有可用的Consul服务导致连接失败，可以根据测试需求选择以下任意一种方案解决：

方案1：使用Testcontainers启动临时Consul实例（集成测试推荐） #

该方案会在测试执行时自动拉起轻量Consul容器，测试结束后自动销毁，完全不依赖服务器预装Consul。
操作步骤：

• 首先在pom.xml中添加Testcontainers相关依赖：

<dependency>
    <groupId>org.testcontainers</groupId>
    <artifactId>junit-jupiter</artifactId>
    <version>1.17.6</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.testcontainers</groupId>
    <artifactId>consul</artifactId>
    <version>1.17.6</version>
    <scope>test</scope>
</dependency>

• 修改测试类，将Testcontainers启动的Consul地址绑定到Spring配置：

package com.example.demo2;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.consul.discovery.ConsulDiscoveryClient;
import org.springframework.test.context.DynamicPropertyRegistry;
import org.springframework.test.context.DynamicPropertySource;
import org.testcontainers.consul.ConsulContainer;
import org.testcontainers.junit.jupiter.Container;
import org.testcontainers.junit.jupiter.Testcontainers;

import java.util.List;
import static org.assertj.core.api.Assertions.assertThat;
import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;

@Testcontainers
@SpringBootTest
class Demo2ApplicationTests {
    @Container
    static final ConsulContainer consulContainer = new ConsulContainer("hashicorp/consul:1.14");

    @DynamicPropertySource
    static void registerConsulProperties(DynamicPropertyRegistry registry) {
        registry.add("spring.cloud.consul.host", consulContainer::getHost);
        registry.add("spring.cloud.consul.port", consulContainer::getMappedPort);
        // 可在此处提前配置测试需要的服务注册、元数据等内容
    }

    @Autowired
    private ConsulDiscoveryClient discoveryClient;

    @Test
    void contextLoads() {
    }

    @Test
    public void testClient() {
        List<ServiceInstance> instances = this.discoveryClient.getInstances("testConsulDiscovery");
        assertThat(instances).as("instances was null").isNotNull();
        assertThat(instances.isEmpty()).as("instances was empty").isFalse();

        ServiceInstance instance = instances.get(0);
        assertThat(instance.isSecure()).as("instance was secure (https)").isFalse();
        assertIpAddress(instance);
        assertThat(instance.getMetadata()).containsEntry("foo", "bar");
    }
}

• 只需保证Maven构建服务器安装了Docker环境即可，无需单独配置Consul。

方案2：Mock ConsulDiscoveryClient（单元测试推荐） #

如果不需要测试和真实Consul的交互逻辑，只需要验证业务代码，可以直接Mock掉ConsulDiscoveryClient，不需要启动真实服务。
修改测试类如下：

package com.example.demo2;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.consul.discovery.ConsulDiscoveryClient;

import java.util.List;
import java.util.Map;
import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.Mockito.when;
import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;

@SpringBootTest
class Demo2ApplicationTests {
    @MockBean
    private ConsulDiscoveryClient discoveryClient;

    @Test
    void contextLoads() {
    }

    @Test
    public void testClient() {
        // 构造Mock返回数据
        ServiceInstance mockInstance = new ServiceInstance() {
            @Override
            public String getServiceId() { return "testConsulDiscovery"; }
            @Override
            public String getHost() { return "127.0.0.1"; }
            @Override
            public int getPort() { return 8080; }
            @Override
            public boolean isSecure() { return false; }
            @Override
            public Map<String, String> getMetadata() { return Map.of("foo","bar"); }
            @Override
            public URI getUri() { return URI.create("http://127.0.0.1:8080"); }
        };
        when(discoveryClient.getInstances("testConsulDiscovery")).thenReturn(List.of(mockInstance));

        List<ServiceInstance> instances = this.discoveryClient.getInstances("testConsulDiscovery");
        assertThat(instances).as("instances was null").isNotNull();
        assertThat(instances.isEmpty()).as("instances was empty").isFalse();

        ServiceInstance instance = instances.get(0);
        assertThat(instance.isSecure()).as("instance was secure (https)").isFalse();
        assertIpAddress(instance);
        assertThat(instance.getMetadata()).containsEntry("foo", "bar");
    }
}

方案3：配置Maven Profile跳过Consul相关测试 #

如果暂时不需要在构建服务器运行这部分测试，可以配置Profile在无Consul环境自动跳过对应测试：

• 在pom.xml中添加Profile配置：

<profiles>
    <profile>
        <id>no-consul</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <configuration>
                        <excludedTestClasses>
                            <exclude>com.example.demo2.Demo2ApplicationTests</exclude>
                        </excludedTestClasses>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </profile>
</profiles>

本地运行测试时指定其他Profile即可执行完整测试，构建服务器默认会跳过Consul相关测试。

内容的提问来源于stack exchange，提问作者Tom