work.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
3.2、zuul gateway工程启动类：
package cn.springcloud.book;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
@SpringBootApplication
@EnableZuulProxy
@EnableDiscoveryClient
public class ZuulGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(ZuulGatewayApplication.class, args);
}
}
3.3、zuul gateway工程配置文件，这里使用2个gateway实例来演示fallback到remote region的应用实例功能，配置文件一个属于region-east，一个属于region-west。
application.yml：
spring:
application:
name: zuul-gateway
management:
endpoints:
web:
exposure:
include: '*'
application-zone1.yml：
server:
port: 10001
eureka:
instance:
metadataMap.zone: zone1
client:
register-with-eureka: true
fetch-registry: true
region: region-east
service-url:
zone1: http://localhost:8761/eureka/
zone2: http://localhost:8762/eureka/
availability-zones:
region-east: zone1,zone2
application-zone3-region-west.yml：
server:
port: 10002
eureka:
instance:
metadataMap.zone: zone3
client:
register-with-eureka: true
fetch-registry: true
region: region-west
service-url:
zone3: http://localhost:8763/eureka/
zone4: http://localhost:8764/eureka/
availability-zones:
region-west: zone3,zone4
3.4、启动gateway工程，执行命令：
mvn spring-boot:run -Dspring.profiles.active=zone1
mvn spring-boot:run -Dspring.profiles.active=zone3-region-west
访问：localhost:10001/demo-client/actuator/env，结果如下：
访问：localhost:10002/demo-client/actuator/env，结果如下：
可以看到ZoneAffinity特性（上一篇文章有讲），zone1的gateway访问的是zone1的demo-client，zone3的gateway访问的是zone3的demo-client。
接下来，关闭eureka-client的zone1实例，继续访问 localhost:10001/demo-client/actuator/env，可以看到在经过几个错误之后，自动fallback到了remote-region的zone4实例上，实现了类似异地多活自动转移请求的效果。
