问题背景

根据上一篇文章完成了 Gateway+FeignClient+Nacos 的初步搭建，这篇添加 Sleuth 链路追踪
注意事项：

可以根据文中的代码自己创建工程，也可以直接下载源码进行学习
默认已安装JDK
可以根据文章自检创建工程，也可以直接下载源码进行参考

Gateway+Nacos+Sleuth+Zipkin网关链路追踪（测试及源码），Gateway+FeignClient+Nacos通过网关远程调用微服务（一）

Gateway+Nacos+Sleuth+Zipkin网关链路追踪（测试及源码），Gateway+Nacos+Sleuth链路追踪（二）

Gateway+Nacos+Sleuth+Zipkin网关链路追踪（测试及源码），Gateway+Nacos+Zipkin安装部署可视化http方式链路追踪（三）

Gateway+Nacos+Sleuth+Zipkin网关链路追踪（测试及源码），Gateway+Nacos+Zipkin持久化mysql存储rabbitmq消息队列链路追踪（四）

项目搭建

1 sleuth链路追踪可以直接根据上一篇文章的代码，再添加一个sleuth依赖

<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-sleuth</artifactId>
</dependency>

整个pom如下，service公共pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.yg</groupId>
    <artifactId>sleuthTest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <modules>
        <module>service1</module>
        <module>service2</module>
    </modules>

    <name>sleuthTest</name>
    <description>sleuthTest</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>


        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<!--            <version>2.1.0.RELEASE</version>-->
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-sleuth</artifactId>
        </dependency>

    </dependencies>

    <dependencyManagement>
        <dependencies>
            <!--Spring Cloud-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

gateway服务的pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yg</groupId>
    <artifactId>gateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>gateway</name>
    <description>gateway</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
<!--            <version>2.1.0.RELEASE</version>-->
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
<!--            <scope>test</scope>-->
        </dependency>

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<!--            <version>2.1.0.RELEASE</version>-->
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-sleuth</artifactId>
        </dependency>

    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

2 其他东西都不用改，只需要引入依赖，现在新的版本logback都不用添加，默认会打印traceID和spanID

项目测试

1 启动nacos服务端，gateway，service1，service2

2 查看注册中心http://localhost:8848/nacos，密码和账号都为：nacos

3 使用网关路由调用service1微服务API，service1微服务调用service2

4 查看gateway的日志，可以看到红框，gateway是微服务名，后面接着是traceID和spanID

5 查看service1微服务的日志，service1微服务名，后面接着是traceID和spanID

6 可以从上两张图看到service1的traceID和gateway的traceID和spanID相同，gateway是起始调用，所以traceID和spanID相同
7 如果微服务过多，这种方式查看及其不方便，所以下一章介绍zipkin