POM文件依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<!--gateway fhadmin.org-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
<version>3.0.2</version>
</dependency>
<!--spring-boot fhadmin.org-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
我在父组件中加入的nacos的相关依赖如下：
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
<version>${nacos.version}</version>
</dependency>
<!--alibaba fhadmin.org-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>${nacos.version}</version>
</dependency>
nacos的版本如下：
<properties>
<nacos.version>2021.1</nacos.version>
</properties>
gateway的application.yml文件配置如下：
#fhadmin.org
server:
port: 9040
spring:
application:
name: gateway
cloud:
gateway:
routes:
- id: consumer
uri: lb://consumer
# uri: http://localhost:9010
predicates:
- Path=/**
nacos:
discovery:
server-addr: localhost:8848
metadata:
preserved.heart.beat.interval: 3 #心跳间隔。时间单位:秒。心跳间隔
preserved.heart.beat.timeout: 6 #心跳暂停。时间单位:秒。 即服务端6秒收不到客户端心跳，会将该客户端注册的实例设为不健康：
preserved.ip.delete.timeout: 9 #Ip删除超时。时间单位:秒。即服务端9秒收不到客户端心跳，会将该客户端注册的实例删除：
当我通过uri: http://localhost:9010去调用服务时，是可以调用的，但是当我用uri lb://consumer时就无法调用服务，报错503.
解决办法是：
加入feign依赖。
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
<version>3.0.2</version>
</dependency>
<!--fegin组件 fhadmin.org-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>3.0.2</version>
</dependency>
<!-- Feign Client for loadBalancing -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-loadbalancer</artifactId>
<version>3.0.2</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
猜测原因：nacos兼容feign，feign集成ribbon，默认实现负载均衡；或许是nacos不兼容springcloud gateway自带的ribbon。
