Getway网关管理ZUUL
1.ZUUL微服务网关
微服务架构体系中，通常一个业务系统会有很多的微服务，比如：OrderService、ProductService、UserService...，为了让调用更简单，一般会在这些服务前端再封装一层，类似下面这样：
image.png
这样做，当然能跑起来，但是维护量大，以后各个微服务增加了新方法，都需要在网关层手动增加相应的方法封装，而spring cloud 中的zuul很好的解决了这一问题，示意图如下：
image.png
Zuul做为网关层，自身也是一个微服务，跟其它服务Service-1，Service-2, ... Service-N一样，都注册在eureka server上，可以相互发现，zuul能感知到哪些服务在线，同时通过配置路由规则（后面会给出示例），可以将请求自动转发到指定的后端微服务上，对于一些公用的预处理（比如：权限认证，token合法性校验，灰度验证时部分流量引导之类）,可以放在所谓的过滤器(ZuulFilter)里处理，这样后端服务以后新增了服务，zuul层几乎不用修改。
2.代码实现:
代码的机构图如下:
image.png
pom.xml:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com</groupId>
<artifactId>stu-zuul</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>stu-zuul</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
<version>1.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
启动类:
StuZuulApplication:
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;
//启动类加上注解@EnableZuulProxy
//它默认加上了@EnableCircuitBreaker和@EnableDiscoveryClient
@SpringBootApplication
@EnableZuulProxy
public class StuZuulApplication {
public static void main(String[] args) {
SpringApplication.run(StuZuulApplication.class, args);
}
}
熔断器:
这个地方我用的springboot版本比较高,网上大部分是之前的版本的熔断器的配置,如果产生冲突可以看下是否有哦依赖版本冲突的问题:
MyFallbackProvider
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import com.netflix.hystrix.exception.HystrixTimeoutException;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;
@Component
public class MyFallbackProvider implements FallbackProvider {
@Override
public String getRoute() {
// 表明是为哪个微服务提供回退，*表示为所有微服务提供回退
return "*";
}
@Override
public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
return null;
}
public ClientHttpResponse fallbackResponse(Throwable cause) {
if (cause instanceof HystrixTimeoutException) {
return response(HttpStatus.GATEWAY_TIMEOUT);
} else {
return this.fallbackResponse();
}
}
public ClientHttpResponse fallbackResponse() {
return this.response(HttpStatus.INTERNAL_SERVER_ERROR);
}
private ClientHttpResponse response(final HttpStatus status) {
return new ClientHttpResponse() {
@Override
public HttpStatus getStatusCode() throws IOException {
return status;
}
@Override
public int getRawStatusCode() throws IOException {
return status.value();
}
@Override
public String getStatusText() throws IOException {
return status.getReasonPhrase();
}
@Override
public void close() {
}
@Override
public InputStream getBody() throws IOException {
return new ByteArrayInputStream("服务不可用，请稍后再试。".getBytes());
}
@Override
public HttpHeaders getHeaders() {
// headers设定
HttpHeaders headers = new HttpHeaders();
MediaType mt = new MediaType("application", "json", Charset.forName("UTF-8"));
headers.setContentType(mt);
return headers;
}
};
}
}
bootstrap.yml:
server:
port: 8040
spring:
application:
name: stu-zuul
eureka:
client:
service-url:
defaultZone: http://user:password123@localhost:8761/eureka
instance:
prefer-ip-address: true
instance-id: ${spring.application.name}:${spring.cloud.client.ipAddress}:${spring.application.instance_id:${server.port}}
hostname: localhost
ip-address: localhost
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds: 60000
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RoundRobinRule #配置规则 轮询
ConnectTimeout: 3000
ReadTimeout: 60000
zuul:
routes:
api-a:
path: /api-provider/**
service-id: stu-provide
sensitive-headers:
api-b:
path: /api-consumer/**
service-id: stu-consumer,stu-consumer-feign-hytrix
上面已经讲到注解了@EnableZuulProxy后,它默认加上了@EnableCircuitBreaker和@EnableDiscoveryClient,
另外他是整合了ribbon的,不需要加额外的注解,但是可以配置相关的负载均衡的规则,下面的配置需要额外注意:
zuul:
routes:
#配置服务提供者的前缀,替代服务注册名,访问的时候就为http://localhost:8040/api-provider/**
api-a:
path: /api-provider/**
service-id: stu-provide
sensitive-headers:
#配置消费者的前缀,替代服务注册名,访问的时候就为http://localhost:8040/api-consumer/**
api-b:
path: /api-consumer/**
service-id: stu-consumer,stu-consumer-feign-hytrix
启动后进行访问,会得到相关提供者的信息.
