Spring Cloud Gateway + Nacos 灰度发布

前言

本文将会使用 SpringCloud Gateway 网关组件配合 Nacos 实现灰度发布(金丝雀发布)

环境搭建

创建子模块服务提供者 provider,网关模块 gateway

父项目

pom.xml 配置

  4.0.0 com.example spring-gateway-demo 0.0.1-SNAPSHOT pom spring-gateway-demo spring-gateway-demo  11 11 11 3.8.1 2.3.7.RELEASE 2.2.2.RELEASE Hoxton.SR9 2.2.0.RELEASE   provider gateway    com.alibaba.cloud spring-cloud-starter-alibaba-nacos-config   com.alibaba.cloud spring-cloud-starter-alibaba-nacos-discovery      org.springframework.cloud spring-cloud-dependencies ${spring-cloud.version} pom import   org.springframework.boot spring-boot-dependencies ${spring-boot.version} pom import   com.alibaba.cloud spring-cloud-alibaba-dependencies ${spring-cloud-alibaba.version} pom import    

服务提供者 provider

这里我们计划引入 nacos, 所以先创建一个 nacos 配置文件 dataId 为 provider.properties, 这里用默认的命名空间 public, 默认分组 DEFAULT_GROUP

version=2

provider 的 pom 配置依赖

  org.springframework.boot spring-boot-starter-web   org.springframework.boot spring-boot-starter-test test   org.junit.vintage junit-vintage-engine    

application.yml

server:  
  port: 9001  
spring:  
  application:  
    name: provider  
  cloud:  
    nacos:  
      config:  
        server-addr: 127.0.0.1:8848  
      discovery:  
        server-addr: 127.0.0.1:8848

启动类上添加 @EnableDiscoveryClient 注解

@EnableDiscoveryClient
@SpringBootApplication
public class ProviderApplication { public static void main(String[] args) { SpringApplication.run(ProviderApplication.class, args);
    }
}

然后添加测试 controller

@RefreshScope
@RestController
@RequestMapping("/test")
public class TestController { @Autowired
    private Environment env;
    @Value("${version:0}")
    private String version;
    /**
     * http://localhost:9001/test/port
     * @return
     */
    @GetMapping("/port")
    public Object port() { return String.format("port=%s, version=%s", env.getProperty("local.server.port"), version);
    }
}

注意,这里配置 nacos 的时候需要配置下面两个文件 provider.properties 和 provider,然后实际配置最终 nacos 是采用的 provider 文件,否则后端控制台就会持续输出 400 错误,可能是新版本问题,其他版本暂时不清楚(后面网关配置也是同理)

后端控制台输出,也可以看出需要两个

[fixed-localhost_8848] [subscribe] provider.properties+DEFAULT_GROUP
[fixed-localhost_8848] [add-listener] ok, tenant=, dataId=provider.properties, group=DEFAULT_GROUP, cnt=1
[fixed-localhost_8848] [subscribe] provider+DEFAULT_GROUP
[fixed-localhost_8848] [add-listener] ok, tenant=, dataId=provider, group=DEFAULT_GROUP, cnt=1

Nacos 版本:2.3.0-BETA

网关 gateway

gateway 服务的 pom 依赖配置如下:

   org.springframework.cloud spring-cloud-starter-gateway   org.projectlombok lombok true   org.springframework.boot spring-boot-starter-test test   org.junit.vintage junit-vintage-engine     org.springframework.boot spring-boot-starter-actuator   

application.yml

# 应用服务 WEB 访问端口  
server:  
  port: 9000  
# 应用名称  
spring:  
  application:  
    name: gateway  
  cloud:  
    nacos:  
      config:  
        server-addr: 127.0.0.1:8848  
      discovery:  
        server-addr: 127.0.0.1:8848  
    gateway:  
      routes: # http://127.0.0.1:9000/actuator/gateway/routes  
        - id: provider  # 路由 ID,保持唯一  
          uri: lb://provider # uri指目标服务地址,lb代表从注册中心获取服务  
          predicates:  
            - Path=/provider/**  # http://127.0.0.1:9000/provider/port 会转发到 http://localhost:9001/provider/port, 和预期不符合, 需要StripPrefix来处理  
          filters:  
            - StripPrefix=1 # StripPrefix=1就代表截取路径的个数为1, 这样请求 http://127.0.0.1:9000/provider/test/port 会转发到 http://localhost:9001/test/port  
management:  
  endpoint:  
    gateway:  
      enabled: true  
  endpoints:  
    web:  
      exposure:  
        include: gateway

同样启动类上添加 @EnableDiscoveryClient 注解

查看所有路由:/actuator/gateway/routes

查看指定路由(GET):/actuator/gateway/routes/{id}

查看全局过滤器:/actuator/gateway/globalfilters

查看路由过滤器:/actuator/gateway/routefilters

POST 方式刷新路由缓存:/actuator/gateway/refresh

测试

curl http://127.0.0.1:9001/test/port
port=9001, version=2
curl http://127.0.0.1:9000/provider/test/port
port=9001, version=2

动态路由

实现动态路由有两种方式,一个是改写 RouteDefinitionRepository(实测失败),一个是基于 nacos 的监听器给 RouteDefinitionRepository 动态更新值。实现逻辑大同小异

Spring Cloud Gateway 中加载路由信息分别由以下几个类负责

1、PropertiesRouteDefinitionLocator:从配置文件中读取路由信息 (如 YML、Properties 等)

2、RouteDefinitionRepository:从存储器中读取路由信息 (如内存、配置中心、Redis、MySQL 等)

3、DiscoveryClientRouteDefinitionLocator:从注册中心中读取路由信息(如 Nacos、Eurka、Zookeeper 等)

下面使用 RouteDefinitionRepository 配置动态路由

gateway-router.json

[{ "id": "provider",
    "predicates": [{ "name": "Path",
        "args": { "_genkey_0": "/provider/**"
        }
    }],
    "filters": [{ "name": "StripPrefix",
        "args": { "_genkey_0": "1"
        }
    }],
    "uri": "lb://provider",
    "order": 0
}]

NacosRouteDefinitionRepository 配置类

@Component  
public class NacosRouteDefinitionRepository implements RouteDefinitionRepository, ApplicationEventPublisherAware { private static final Logger log = LoggerFactory.getLogger(NacosRouteDefinitionRepository.class);  
  
    @Autowired  
    private NacosConfigManager nacosConfigManager;  
  
    // 更新路由信息需要的  
    private ApplicationEventPublisher applicationEventPublisher;  
  
    private String dataId = "gateway-router.json";  
  
    private String group = "DEFAULT_GROUP";  
  
    @Value("${spring.cloud.nacos.config.server-addr}")  
    private String serverAddr;  
  
    private ObjectMapper objectMapper = new ObjectMapper();  
  
    @PostConstruct  
    public void dynamicRouteByNacosListener() { try { nacosConfigManager.getConfigService().addListener(dataId, group, new Listener() { public void receiveConfigInfo(String configInfo) { log.info("自动更新配置...\r\n{}", configInfo);  
                    applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this));  
                }  
  
                public Executor getExecutor() { return null;  
                }  
            });  
        } catch (NacosException e) { e.printStackTrace();  
        }  
    }  
  
    @Override  
    public Flux getRouteDefinitions() { try { String configInfo = nacosConfigManager.getConfigService().getConfig(dataId, group, 5000);  
            List gatewayRouteDefinitions = objectMapper.readValue(configInfo, new TypeReference>() { });  
            return Flux.fromIterable(gatewayRouteDefinitions);  
        } catch (NacosException e) { e.printStackTrace();  
        } catch (JsonMappingException e) { e.printStackTrace();  
        } catch (JsonProcessingException e) { e.printStackTrace();  
        }  
        return Flux.fromIterable(Lists.newArrayList());  
    }  
  
    @Override  
    public Mono save(Mono route) { return null;  
    }  
  
    @Override  
    public Mono delete(Mono routeId) { return null;  
    }  
  
    @Override  
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) { this.applicationEventPublisher = applicationEventPublisher;  
    }  
}

然后重启网关,访问 http://127.0.0.1:9000/actuator/gateway/routes ,查看是否生效

[
    { "predicate": "Paths: [/provider/**], match trailing slash: true",
        "route_id": "provider",
        "filters": [
            "[[StripPrefix parts = 1], order = 1]"
        ],
        "uri": "lb://provider",
        "order": 0
    }
]

灰度发布

首先需要明白灰度的场景, 因为有不同版本的服务需要共存, 所以新的节点升级的时候必然代码及配置会存在差别, 所以我们根据这种差别来判断服务版本是新版本还是线上稳定版本。这里我们用 prod 和 gray 来标识 2 个版本。

实现的整体思路:

  1. 编写带版本号的灰度路由(负载均衡策略)
  2. 编写自定义 filter
  3. nacos 服务配置需要灰度发布的服务的元数据信息以及权重(在服务 jar 中配置)

注意, 应该先修改 nacos 配置实现动态路由, 然后再升级灰度节点. 本案例只是简单示例灰度原理。

下面进行网关配置

依赖配置

首先排除掉默认的 ribbon 依赖

  com.alibaba.cloud spring-cloud-starter-alibaba-nacos-discovery   org.springframework.cloud spring-cloud-starter-netflix-ribbon   

引入官方新的负载均衡包

  org.springframework.cloud spring-cloud-starter-loadbalancer 

负载均衡策略

public class VersionGrayLoadBalancer implements ReactorServiceInstanceLoadBalancer { private ObjectProvider serviceInstanceListSupplierProvider;
    private String serviceId;
    private final AtomicInteger position;
    public VersionGrayLoadBalancer(ObjectProvider serviceInstanceListSupplierProvider, String serviceId) { this(serviceInstanceListSupplierProvider, serviceId, new Random().nextInt(1000));
    }
    public VersionGrayLoadBalancer(ObjectProvider serviceInstanceListSupplierProvider, String serviceId, int seedPosition) { this.serviceId = serviceId;
        this.serviceInstanceListSupplierProvider = serviceInstanceListSupplierProvider;
        this.position = new AtomicInteger(seedPosition);
    }
    @Override
    public Mono> choose(Request request) { HttpHeaders headers = (HttpHeaders) request.getContext();
        ServiceInstanceListSupplier supplier = this.serviceInstanceListSupplierProvider.getIfAvailable(NoopServiceInstanceListSupplier::new);
        return ((Flux) supplier.get()).next().map(list -> processInstanceResponse((List) list, headers));
    }
    private Response processInstanceResponse(List instances, HttpHeaders headers) { if (instances.isEmpty()) { return new EmptyResponse();
        } else { String reqVersion = headers.getFirst("version");
            if (StringUtils.isEmpty(reqVersion)) { return processRibbonInstanceResponse(instances);
            }
            List serviceInstances = instances.stream()
                    .filter(instance -> reqVersion.equals(instance.getMetadata().get("version")))
                    .collect(Collectors.toList());
            if (serviceInstances.size() > 0) { return processRibbonInstanceResponse(serviceInstances);
            } else { return processRibbonInstanceResponse(instances);
            }
        }
    }
    /**
     * 负载均衡器
     * 参考 org.springframework.cloud.loadbalancer.core.RoundRobinLoadBalancer#getInstanceResponse
     *
     * @author javadaily
     */
    private Response processRibbonInstanceResponse(List instances) { int pos = Math.abs(this.position.incrementAndGet());
        ServiceInstance instance = instances.get(pos % instances.size());
        return new DefaultResponse(instance);
    }
}

过滤器加载负载均衡

public class GrayReactiveLoadBalancerClientFilter implements GlobalFilter, Ordered { private static final Log log = LogFactory.getLog(ReactiveLoadBalancerClientFilter.class);  
    private static final int LOAD_BALANCER_CLIENT_FILTER_ORDER = 10150;  
    private final LoadBalancerClientFactory clientFactory;  
    private LoadBalancerProperties properties;  
  
    public GrayReactiveLoadBalancerClientFilter(LoadBalancerClientFactory clientFactory, LoadBalancerProperties properties) { this.clientFactory = clientFactory;  
        this.properties = properties;  
    }  
  
    @Override  
    public int getOrder() { return LOAD_BALANCER_CLIENT_FILTER_ORDER;  
    }  
  
    @Override  
    public Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) { URI url = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);  
        String schemePrefix = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR);  
        if (url != null && ("grayLb".equals(url.getScheme()) || "grayLb".equals(schemePrefix))) { ServerWebExchangeUtils.addOriginalRequestUrl(exchange, url);  
            if (log.isTraceEnabled()) { log.trace(ReactiveLoadBalancerClientFilter.class.getSimpleName() + " url before: " + url);  
            }  
  
            return this.choose(exchange).doOnNext((response) -> { if (!response.hasServer()) { throw NotFoundException.create(this.properties.isUse404(), "Unable to find instance for " + url.getHost());  
                } else { URI uri = exchange.getRequest().getURI();  
                    String overrideScheme = null;  
                    if (schemePrefix != null) { overrideScheme = url.getScheme();  
                    }  
  
                    DelegatingServiceInstance serviceInstance = new DelegatingServiceInstance((ServiceInstance) response.getServer(), overrideScheme);  
                    URI requestUrl = this.reconstructURI(serviceInstance, uri);  
                    if (log.isTraceEnabled()) { log.trace("LoadBalancerClientFilter url chosen: " + requestUrl);  
                    }  
  
                    exchange.getAttributes().put(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR, requestUrl);  
                }  
            }).then(chain.filter(exchange));  
        } else { return chain.filter(exchange);  
        }  
    }  
  
    protected URI reconstructURI(ServiceInstance serviceInstance, URI original) { return LoadBalancerUriTools.reconstructURI(serviceInstance, original);  
    }  
  
    private Mono> choose(ServerWebExchange exchange) { URI uri = (URI) exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);  
        VersionGrayLoadBalancer loadBalancer = new VersionGrayLoadBalancer(clientFactory.getLazyProvider(uri.getHost(), ServiceInstanceListSupplier.class), uri.getHost());  
        if (loadBalancer == null) { throw new NotFoundException("No loadbalancer available for " + uri.getHost());  
        } else { return loadBalancer.choose(this.createRequest(exchange));  
        }  
    }  
  
    private Request createRequest(ServerWebExchange exchange) { HttpHeaders headers = exchange.getRequest().getHeaders();  
        Request request = new DefaultRequest<>(headers);  
        return request;  
    }  
}

注入过滤器

@Configuration
public class GrayGatewayReactiveLoadBalancerClientAutoConfiguration { @Bean
    @ConditionalOnMissingBean({GrayReactiveLoadBalancerClientFilter.class})
    public GrayReactiveLoadBalancerClientFilter grayReactiveLoadBalancerClientFilter(LoadBalancerClientFactory clientFactory, LoadBalancerProperties properties) { return new GrayReactiveLoadBalancerClientFilter(clientFactory, properties);
    }
}

发布灰度服务

生产环境配置文件 application-prod.yml

server:  
  port: 9002  
spring:  
  application:  
    name: provider  
  cloud:  
    nacos:  
      config:  
        server-addr: 127.0.0.1:8848  
      discovery:  
        metadata:  
          version: prod  
        server-addr: 127.0.0.1:8848

灰度环境配置文件 application-gray.yml

server:  
  port: 9003  
spring:  
  application:  
    name: provider  
  cloud:  
    nacos:  
      config:  
        server-addr: 127.0.0.1:8848  
      discovery:  
        metadata:  
          version: gray  
        server-addr: 127.0.0.1:8848

idea 启动参数指定配置文件

同时注意配置两个环境的 nacos 文件(prod version: 4,gray version: 5)

测试

然后分别启动三个服务:9000 端口网关 gateway 服务,9002 端口生产环境 provider-prod 服务,9003 端口灰度环境 provider-gray 服务

E:\Nacos\nacos>curl http://127.0.0.1:9000/provider/test/port
port=9003, version=5
E:\Nacos\nacos>curl -X GET -H "version:prod" http://127.0.0.1:9000/provider/test/port
port=9003, version=5
E:\Nacos\nacos>curl -X GET -H "version:gray" http://127.0.0.1:9000/provider/test/port
port=9002, version=4

仓库地址

如果对于文章中代码有疑问,可以直接查看下方作者仓库

仓库地址:ReturnTmp/spring-gateway-demo: 网关配置 + 灰度发布 + 配置中心 示例仓库 (github.com)

参考链接

  • Spring Cloud Gateway+nacos灰度发布 - 掘金 (juejin.cn)
  • SpringCloud gateway Actuator - shigp1 - 博客园 (cnblogs.com)
  • Spring Cloud Gateway监控 周立的博客
  • 前端灰度发布落地方案-腾讯云开发者社区-腾讯云 (tencent.com)
  • 后端 - 灰度发布架构设计!值得品鉴

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