Spring Cloud学习笔记—网关Spring Cloud Gateway动态路由实操练习

柔光的暖阳◎ 2022-12-29 04:54 157阅读 0赞

### Spring Cloud学习笔记—网关Spring Cloud Gateway动态路由实操练习 ###

Spring Cloud Gateway的路由规则不管是卸载yml配置文件，还是写代码里，这两种方式都是不支持动态配置的，Spring Cloud Gateway启动时候，就将路由配置和规则加载到内存里，无法做到不重启网关就可以识别yml配置文件和代码配置的变化。下面就详细介绍如何实现Spring Cloud Gateway的动态路由（即不重启网关就能改变路由规则）。

> 本文练习是在《[Spring Cloud学习笔记—Spring Cloud Gateway官网教程实操练习][Spring Cloud_Spring Cloud Gateway]》基础上扩展。

1、在pom.xml中增加spring-boot-starter-actuator依赖（actuator是实现对springboot监控的功能），完整的pom.xml代码如下：

<?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>2.4.2-SNAPSHOT</version>
    		<relativePath/> 
    	</parent>
    	<groupId>wongoing</groupId>
    	<artifactId>ms</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<name>Gateway</name>
    	<description>Demo project for Spring Boot</description>
    
    	<properties>
    		<java.version>1.8</java.version>
    		<spring-cloud.version>2020.0.0-SNAPSHOT</spring-cloud.version>
    	</properties>
    
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-gateway</artifactId>
    		</dependency>
    
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-actuator</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-test</artifactId>
    			<scope>test</scope>
    		</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>
    
    	<repositories>
    		<repository>
    			<id>spring-milestones</id>
    			<name>Spring Milestones</name>
    			<url>https://repo.spring.io/milestone</url>
    		</repository>
    		<repository>
    			<id>spring-snapshots</id>
    			<name>Spring Snapshots</name>
    			<url>https://repo.spring.io/snapshot</url>
    			<snapshots>
    				<enabled>true</enabled>
    			</snapshots>
    		</repository>
    	</repositories>
    	<pluginRepositories>
    		<pluginRepository>
    			<id>spring-milestones</id>
    			<name>Spring Milestones</name>
    			<url>https://repo.spring.io/milestone</url>
    		</pluginRepository>
    		<pluginRepository>
    			<id>spring-snapshots</id>
    			<name>Spring Snapshots</name>
    			<url>https://repo.spring.io/snapshot</url>
    			<snapshots>
    				<enabled>true</enabled>
    			</snapshots>
    		</pluginRepository>
    	</pluginRepositories>
    </project>

2、修改resources/application.yml，增加暴露端点的配置。完整内容如下：

server:
      port: 8080 #指定当前服务的端口号
    
    #暴露端点
    management:
      endpoints:
        web:
          exposure:
            include: '*'
      endpoint:
        health:
          show-details: always
          
    spring:
      application:
        name: gateway
      cloud:
        gateway:
          discovery:
            locator:
              enabled: true #是否适用默认路由（通过gatewayUri:port/服务名/path直接访问服务接口）
              lower-case-service-id: true #是否忽略服务名大小写
          routes:                               #gateway配置多条路由规则时注意顺序问题
          
          - id: service0                        #路由规则ID在上下文中唯一
            uri: http://httpbin.org:80 #路由目标服务地址
            predicates:                         #路由条件:请求的路径为http://localhost:8080/get则自动转发至目标服务
            - Path=/get
            filters:                            #过滤器链
            - AddRequestHeader=Hello, World     #添加请求头
            
          - id: service1
            uri: http://localhost:8090
            predicates:
            - Path=/test
            filters:
            - AddRequestHeader=Author, CodingPioneer

3、在Gateway工程下创建一个包com.wongoing.route存放动态路由的相关类。  
4、在com.wongoing.route包下创建路由断言模型类GatewayPredicateDefinition.java，代码如下：

package com.wongoing.route;
    
    import java.util.LinkedHashMap;
    import java.util.Map;
    
    /** * 功能说明：路由断言模型 * 修改说明： * @author zheng * @date 2020-12-18 13:26:44 * @version 0.1 */
    public class GatewayPredicateDefinition { 
    	//断言对应的Name
    	private String name;
    	//配置断言的规则
    	private Map<String, String> args = new LinkedHashMap<>();
    	
    	public String getName() { 
    		return name;
    	}
    	
    	public void setName(String name) { 
    		this.name = name;
    	}
    	
    	public Map<String, String> getArgs() { 
    		return args;
    	}
    	
    	public void setArgs(Map<String, String> args) { 
    		this.args = args;
    	}
    }

5、在com.wongoing.route包下创建路由过滤器模型类GatewayFilterDefinition.java，代码如下：

package com.wongoing.route;
    
    import java.util.LinkedHashMap;
    import java.util.Map;
    
    /** * 功能说明：路由过滤器模型 * 修改说明： * @author zheng * @date 2020-12-20 15:19:08 * @version 0.1 */
    public class GatewayFilterDefinition { 
    	//Filter Name
    	private String name;
    	//对应的路由规则
    	private Map<String, String> args = new LinkedHashMap<>();
    	
    	public String getName() { 
    		return name;
    	}
    	
    	public void setName(String name) { 
    		this.name = name;
    	}
    	
    	public Map<String, String> getArgs() { 
    		return args;
    	}
    	
    	public void setArgs(Map<String, String> args) { 
    		this.args = args;
    	}
    }

6、在com.wongoing.route包下创建路由模型类GatewayRouteDefinition.java，代码如下：

package com.wongoing.route;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /** * 功能说明：路由模型 * 修改说明： * @author zheng * @date 2020-12-18 13:23:25 * @version 0.1 */
    public class GatewayRouteDefinition { 
    	//路由的Id
    	private String id;
    	//路由断言集合配置
    	private List<GatewayPredicateDefinition> predicates = new ArrayList<>();
    	//路由过滤器集合配置
    	private List<GatewayFilterDefinition> filters = new ArrayList<>();
    	//路由规则转发的目标uri
    	private String uri;
    	//路由执行的顺序
    	private int order = 0;
    	
    	public String getId() { 
    		return id;
    	}
    	
    	public void setId(String id) { 
    		this.id = id;
    	}
    	
    	public List<GatewayPredicateDefinition> getPredicates() { 
    		return predicates;
    	}
    	
    	public void setPredicates(List<GatewayPredicateDefinition> predicates) { 
    		this.predicates = predicates;
    	}
    	
    	public List<GatewayFilterDefinition> getFilters() { 
    		return filters;
    	}
    	
    	public void setFilters(List<GatewayFilterDefinition> filters) { 
    		this.filters = filters;
    	}
    	
    	public String getUri() { 
    		return uri;
    	}
    	
    	public void setUri(String uri) { 
    		this.uri = uri;
    	}
    	
    	public int getOrder() { 
    		return order;
    	}
    	
    	public void setOrder(int order) { 
    		this.order = order;
    	}
    }

7、创建包com.wongoing.route.service，存放动态路由业务类。  
8、在com.wongoing.route.service包下创建动态路由业务实现类DynamicRouteServiceImpl.java，代码如下：

package com.wongoing.route.service;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
    import org.springframework.cloud.gateway.route.RouteDefinition;
    import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
    import org.springframework.cloud.gateway.support.NotFoundException;
    import org.springframework.context.ApplicationEventPublisher;
    import org.springframework.context.ApplicationEventPublisherAware;
    import org.springframework.http.ResponseEntity;
    import org.springframework.stereotype.Service;
    
    import reactor.core.publisher.Mono;
    
    /** * 功能说明：动态路由业务服务实现类 * 修改说明： * @author zheng * @date 2020-12-18 13:59:09 * @version 0.1 */
    @Service
    public class DynamicRouteServiceImpl implements ApplicationEventPublisherAware { 
    	@Autowired
    	private RouteDefinitionWriter routeDefinitionWriter;
    	private ApplicationEventPublisher publisher;
    	
    	
    	@Override
    	public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) { 
    		this.publisher = applicationEventPublisher;
    	}
    	
    	/** * 功能说明：增加路由 * 修改说明： * @author zheng * @date 2020-12-18 13:58:58 * @param definition * @return */
    	public String add(RouteDefinition definition) { 
    		this.routeDefinitionWriter.save(Mono.just(definition)).subscribe();
    		this.publisher.publishEvent(new RefreshRoutesEvent(this));
    		return "success";
    	}
    
    	/** * 功能说明：更新路由 * 修改说明： * @author zheng * @date 2020-12-18 13:36:23 * @param definition * @return */
    	public String update(RouteDefinition definition) { 
    		try { 
    			this.delete(definition.getId());
    		} catch(Exception ex) { 
    			return "update route fail, not find route routeId: " + definition.getId();
    		}
    		try { 
    			this.routeDefinitionWriter.save(Mono.just(definition)).subscribe();
    			this.publisher.publishEvent(new RefreshRoutesEvent(this));
    			return "success";
    		} catch(Exception e) { 
    			return "update route fail";
    		}
    	}
    	
    	/** * 功能说明：删除路由 * 修改说明： * @author zheng * @date 2020-12-18 13:37:05 * @param id * @return */
    	public Mono<ResponseEntity<Object>> delete(String id) { 
    		return this.routeDefinitionWriter.delete(Mono.just(id)).then(Mono.defer(() -> {  
    			this.publisher.publishEvent(new RefreshRoutesEvent(this));
    			ResponseEntity<Object> result = ResponseEntity.ok().build();
    			return Mono.just(result);
    		})).onErrorResume((t) -> { 
    			return t instanceof NotFoundException;
    		}, (t) -> { 
    			return Mono.just(ResponseEntity.notFound().build());
    		});
    	}
    }

9、创建包com.wongoing.rute.controller，存放动态路由控制器类。  
10、在com.wongoing.rute.controller包下创建控制器类RouteController.java，代码如下：

package com.wongoing.route.controller;
    
    import java.net.URI;
    import java.util.ArrayList;
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cloud.gateway.filter.FilterDefinition;
    import org.springframework.cloud.gateway.handler.predicate.PredicateDefinition;
    import org.springframework.cloud.gateway.route.RouteDefinition;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.bind.annotation.DeleteMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.util.UriComponentsBuilder;
    
    import com.wongoing.route.GatewayFilterDefinition;
    import com.wongoing.route.GatewayPredicateDefinition;
    import com.wongoing.route.GatewayRouteDefinition;
    import com.wongoing.route.service.DynamicRouteServiceImpl;
    
    import reactor.core.publisher.Mono;
    
    /** * 功能说明：路由控制器类 * 修改说明： * @author zheng * @date 2020-12-18 13:59:31 * @version 0.1 */
    @RestController
    @RequestMapping("/route")
    public class RouteController { 
    	
    	@Autowired
    	private DynamicRouteServiceImpl dynamicRouteService;
    	
    	/** * 功能说明：增加路由 * 修改说明： * @author zheng * @date 2020-12-18 13:45:33 * @param gwdefinition * @return */
    	@PostMapping("/add")
    	public String add(@RequestBody GatewayRouteDefinition gwdefinition) { 
    		String flag = "fail";
    		try { 
    			RouteDefinition definition = assembleRouteDefinition(gwdefinition);
    			flag = this.dynamicRouteService.add(definition);
    		} catch (Exception e) { 
    			e.printStackTrace();
    		}
    		return flag;
    	}
    	
    	/** * 功能说明：删除路由 * 修改说明： * @author zheng * @date 2020-12-18 14:08:45 * @param id * @return */
    	@DeleteMapping("/routes/{id}")
    	public Mono<ResponseEntity<Object>> delete(@PathVariable String id) { 
    		try { 
    			System.out.println("This delete id is : " + id);
    			return this.dynamicRouteService.delete(id);
    		} catch (Exception e) { 
    			e.printStackTrace();
    		}
    		return null;
    	}
    	
    	/** * 功能说明：更新路由 * 修改说明： * @author zheng * @date 2020-12-18 14:11:35 * @param gwdefinition * @return */
    	@PostMapping("/update")
    	public String update(@RequestBody GatewayRouteDefinition gwdefinition) { 
    		RouteDefinition definition = assembleRouteDefinition(gwdefinition);
    		return this.dynamicRouteService.update(definition);
    	}
    	
    	/** * 功能说明：把传递进来的参数转换成路由对象 * 修改说明： * @author zheng * @date 2020-12-18 13:47:29 * @param gwdefinition * @return */
    	private RouteDefinition assembleRouteDefinition(GatewayRouteDefinition gwdefinition) { 
    		RouteDefinition definition = new RouteDefinition();
    		definition.setId(gwdefinition.getId());
    		definition.setOrder(gwdefinition.getOrder());
    		
    		//设置断言
    		List<PredicateDefinition> pdList = new ArrayList<>();
    		List<GatewayPredicateDefinition> gatewayPredicateDefinitionList = gwdefinition.getPredicates();
    		for (GatewayPredicateDefinition gpDefinition : gatewayPredicateDefinitionList) { 
    			PredicateDefinition predicate = new PredicateDefinition();
    			predicate.setArgs(gpDefinition.getArgs());
    			predicate.setName(gpDefinition.getName());
    			pdList.add(predicate);
    		}
    		definition.setPredicates(pdList);
    		
    		//设置过滤器
    		List<FilterDefinition> filters = new ArrayList<>();
    		List<GatewayFilterDefinition> gatewayFilters = gwdefinition.getFilters();
    		for(GatewayFilterDefinition filterDefinition : gatewayFilters) { 
    			FilterDefinition filter = new FilterDefinition();
    			filter.setName(filterDefinition.getName());
    			filter.setArgs(filterDefinition.getArgs());
    			filters.add(filter);
    		}
    		definition.setFilters(filters);
    		
    		URI uri = null;
    		if (gwdefinition.getUri().startsWith("http")) { 
    			uri = UriComponentsBuilder.fromHttpUrl(gwdefinition.getUri()).build().toUri();
    		} else {  
    			//uri为 lb://consumer-service 时使用下面的方法
    			uri = URI.create(gwdefinition.getUri());
    		}
    		definition.setUri(uri);
    		return definition;
    	}
    }

11、启动Gateway项目，使用Postman进行测试。  
12、通过actuator查看已有的路由配置。  
在Postman中建立一个GET请求，地址是：http://localhost:8080/actuator/gateway/routes，执行结果如下图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3psYmRtbQ_size_16_color_FFFFFF_t_70]  
这里列出的是resources/application.yml中配置的路由规则。  
13、测试新增一个路由。  
在Postman中新增一个POST请求，请求地址是：http://localhost:8080/route/update，在请求的Body选项中选择raw，数据类别选择JSON，然后在请求的内容部分输入以下内容：

{ 
        "id":"service3",
        "uri":"http://www.coding123.cn:80",
        "order":1,
        "predicates":[{ "name":"Path", "args":{ "pattern":"/demo/threejs/threejs_demo1.html"}}],
        "filters":[{ "name":"AddRequestHeader", "args":{ "_genkey_0":"test", "_genkey_1":"testValue"}}]
    }

执行结果，如下图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3psYmRtbQ_size_16_color_FFFFFF_t_70 1]  
14、重新执行第12步，看看执行结果中有没有新增路由，执行结果如下图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3psYmRtbQ_size_16_color_FFFFFF_t_70 2]  
当然也可以通过在浏览器地址栏中输入：http://localhost:8080/demo/threejs/threejs\_demo1.html测试路由是否生效，我测试是通过的。  
15、删除刚刚添加的那个路由规则。  
在Postman中新增一个DELETE请求，在地址栏中输入：http://localhost:8080/route/routes/service3，执行结果如下图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3psYmRtbQ_size_16_color_FFFFFF_t_70 3]  
16、重新执行第12步验证相应的路由规则是否已删除，执行结果如下图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3psYmRtbQ_size_16_color_FFFFFF_t_70 4]  
在浏览器地址栏中输入http://localhost:8080/demo/threejs/threejs\_demo1.html发现已无法正常显示。  
17、总结  
通过上面的过程我们已经实现了动态增删路由规则的功能。也有一些注意点：

>  *  application.yml中配置的路由和初始化代码中编写的路由是不能删除和修改的。
>  *  动态增删路由是操作的org.springframework.cloud.gateway.route.RouteDefinitionRepository中的路由信息。
>  *  application.yml中配置的路由和初始化代码中的路由是在org.springframework.cloud.gateway.route.RouteDefinitionLocator中的。
>  *  而/actuator/gateway/routes中监控的是所有的路由信息。

[Spring Cloud_Spring Cloud Gateway]: https://coding123.blog.csdn.net/article/details/111317440
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