👊【SpringCloud技术专题】超级详细的Gateway网关的技术指南
SpringCloud Gateway简介
Gateway网关特性
统一入口所有请求通过网关路由到内部其他服务。 断言(Predicates)和过滤器(filters)特定路由。断言是根据具体的请求的规则由route去处理；过滤器用来对请求做各种判断和修改。 可集成熔断器:Hystrix 熔断机制。Hystrix是 spring cloud gateway中是以filter的形式使用的。 流量限速：请求限流防止大规模请求对业务数据造成破坏。 路径重写（rewrite）:路径重写自定义路由转发规则。 能够自由设置任何请求属性的路由 Spring Cloud DiscoveryClient原生支持
Gateway流程架构
静态路由
方法一 配置文件方式
spring:
cloud:
gateway:
routes:
- id: ingredients
uri: lb://ingredients
predicates:
- Path=//ingredients/**
filters:
- name: CircuitBreaker
args:
name: fetchIngredients
fallbackUri: forward:/fallback
- id: ingredients-fallback
uri: http://localhost:9994
predicates:
- Path=/fallback
filters:
- name: FallbackHeaders
args:
executionExceptionTypeHeaderName: Test-Header
- id: ijep-service-sys #基础服务
uri: lb://ijep-service-sys
predicates:
- Path=/api/sys/**
filters:
- StripPrefix=2方法二 代码构建路由
// static imports from GatewayFilters and RoutePredicates
@Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder, ThrottleGatewayFilterFactory throttle) {
return builder.routes()
.route(r -> r.host("**.abc.org").and().path("/image/png")
.filters(f ->
f.addResponseHeader("X-TestHeader", "foobar"))
.uri("http://httpbin.org:80")
)
.route(r -> r.path("/image/webp")
.filters(f ->
f.addResponseHeader("X-AnotherHeader", "baz"))
.uri("http://httpbin.org:80")
.metadata("key", "value")
)
.route(r -> r.order(-1)
.host("**.throttle.org").and().path("/get")
.filters(f -> f.filter(throttle.apply(1,
1,
10,
TimeUnit.SECONDS)))
.uri("http://httpbin.org:80")
.metadata("key", "value")
)
.build();
}断言(Predicates)
过滤器(Filter)
GlobalFilter 全局过滤器
CORS跨域处理
Gateway API
无论是哪一种，在启动网关后将无法修改路由配置，如有新服务要上线，则需要先把网关下线，修改 yml 配置后，再重启网关。
动态路由
package org.springframework.cloud.gateway.route;
@Validated
public class RouteDefinition {
@NotEmpty
private String id = UUID.randomUUID().toString();
@NotEmpty
@Valid
private List predicates = new ArrayList<>();
@Valid
private List filters = new ArrayList<>();
@NotNull
private URI uri;
private int order = 0;
public RouteDefinition() {}
.....此处省略......
} package org.springframework.cloud.gateway.route;
import reactor.core.publisher.Flux;
public interface RouteDefinitionLocator {
Flux getRouteDefinitions();
}
处。
Gateway Endpoint 端点
org.springframework.boot
spring-boot-starter-actuator
yml配置
# 暴露端点
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: always动态路由实现
创建路由模型
过滤器模型
public class GatewayFilterDefinition {
//Filter Name
private String name;
//对应的路由规则
private Map args = new LinkedHashMap<>();
......此处省略Get、Set方法......
} 路由断言模型
public class GatewayPredicateDefinition {
//断言对应的Name
private String name;
//配置的断言规则
private Map args = new LinkedHashMap<>();
......此处省略Get、Set方法......
} 路由模型
public class GatewayRouteDefinition {
//路由的Id
private String id;
//路由断言集合配置
private List predicates = new ArrayList<>();
//路由过滤器集合配置
private List 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;
......此处省略Get、Set方法......
} 编写态路由实现类，实现ApplicationEventPublisherAware接口
@Service
public class DynamicRouteServiceImpl implements ApplicationEventPublisherAware{
@Autowired
private RouteDefinitionWriter routeDefinitionWriter;
private ApplicationEventPublisher publisher;
@Override
public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
this.publisher = applicationEventPublisher;
}
/**
* 增加路由
* @param definition
* @return
*/
public String add(RouteDefinition definition) {
routeDefinitionWriter.save(Mono.just(definition)).subscribe();
this.publisher.publishEvent(new RefreshRoutesEvent(this));
return "success";
}
/**
* 更新路由
* @param definition
* @return
*/
public String update(RouteDefinition definition) {
try {
delete(definition.getId());
} catch (Exception e) {
return "update fail,not find route routeId: "+definition.getId();
}
try {
routeDefinitionWriter.save(Mono.just(definition)).subscribe();
this.publisher.publishEvent(new RefreshRoutesEvent(this));
return "success";
} catch (Exception e) {
return "update route fail";
}
}
/**
* 删除路由
* @param id
* @return
*/
public Mono> delete(String id) {
return this.routeDefinitionWriter.delete(Mono.just(id)).then(Mono.defer(() -> {
return Mono.just(ResponseEntity.ok().build());
})).onErrorResume((t) -> {
return t instanceof NotFoundException;
}, (t) -> {
return Mono.just(ResponseEntity.notFound().build());
});
}
} 编写API接口，实现动态路由功能
@RestController
@RequestMapping("/api/route")
public class RouteRestController {
@Autowired
private DynamicRouteServiceImpl dynamicRouteService;
/**
* 增加路由
* @param gatewayRouteDefinition 路由模型
* 报文:{"filters":[{"name":"StripPrefix","args":{"_genkey_0":"2"}}],"id":"ijep-service-sys-hyk11","uri":"lb://ijep-service-sys","order":2,"predicates":[{"name":"Path","args":{"_genkey_0":"/api/hyk11/**"}}]}
* @return
*/
@PostMapping("/add")
public RestResponse add(@RequestBody GatewayRouteDefinition gatewayRouteDefinition) {
String flag = "fail";
try
{
RouteDefinition definition = assembleRouteDefinition(gatewayRouteDefinition);
flag = this.dynamicRouteService.add(definition);
} catch (Exception e) {
e.printStackTrace();
}
return RestResponseBuilder.restResponse().data(flag).build();
}
/**
* 更新路由
* @param gatewayRouteDefinition 路由模型
* 报文:{"filters":[{"name":"StripPrefix","args":{"_genkey_0":"2"}}],"id":"ijep-service-sys-hyk11","uri":"lb://ijep-service-sys","order":2,"predicates":[{"name":"Path","args":{"_genkey_0":"/api/hyk11/**"}}]}
* @return
*/
@PostMapping("/update")
public RestResponse update(@RequestBody GatewayRouteDefinition gatewayRouteDefinition) {
RouteDefinition definition = assembleRouteDefinition(gatewayRouteDefinition);
String flag = this.dynamicRouteService.update(definition);
return RestResponseBuilder.restResponse().data(flag).build();
}
/**
* 删除路由
* @param id 路由Id
* @return
*/
@DeleteMapping("/routes/{id}")
public RestResponse delete(@PathVariable String id) {
Mono> responseEntityMono = this.dynamicRouteService.delete(id);
return RestResponseBuilder.restResponse().data(responseEntityMono).build();
}
/**
* 把传递进来的参数转换成路由对象
* @param gatewayRouteDefinition 路由模型
* @return
*/
private RouteDefinition assembleRouteDefinition(GatewayRouteDefinition gatewayRouteDefinition) {
RouteDefinition definition = new RouteDefinition();
definition.setId(gatewayRouteDefinition.getId());
definition.setOrder(gatewayRouteDefinition.getOrder());
//设置断言
List pdList = new ArrayList<>();
List gatewayPredicateDefinitionList = gatewayRouteDefinition.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 filters = new ArrayList();
List gatewayFilters = gatewayRouteDefinition.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(gatewayRouteDefinition.getUri().startsWith("http")){
uri = UriComponentsBuilder.fromHttpUrl(gatewayRouteDefinition.getUri()).build().toUri();
}else{
// uri为 lb://consumer-service 时使用下面的方法
uri = URI.create(gatewayRouteDefinition.getUri());
}
definition.setUri(uri);
return definition;
}
} 新增路由接口
