springcloud + nacos多环境联调、本地联调（即灰度版本）

背景

当我们使用nacos为注册中心注册微服务时想本地环境和测试环境公用一个nacos即注册中心等基础服务共用。当我们在服务A开发时本地服务和测试环境服务都是注册到同一个nacos由于nacos自带负载均衡策略调用服务时就会使用负载均衡选择服务导致我们无法正常调试接口。这时我们可以选择使用灰度版本来进行服务的选择。

废话不多说直接开干

首先声明一点我springcloud环境如下

<spring-boot.version>2.3.2.RELEASE</spring-boot.version>

<spring-cloud-alibaba.version>2.2.5.RELEASE</spring-cloud-alibaba.version>

<spring-cloud.version>Hoxton.SR8</spring-cloud.version>

nacos版本是2.1.4

具体实现步骤如下

1、我们在配置文件中添加版本头开发环境版本dev我本地环境设置xf

spring.cloud.nacos.discovery.metadata.VERSION=xf

2、添加灰度服务接口

/**

* @author xf

* @Title:

* @Description:

* @date 2023/1/12 17:17

*/

public interface GrayLoadBalancer {

/**

* 根据serviceId 筛选可用服务

* @param serviceId 服务ID

* @param request 当前请求

* @param exchange 请求不到目标实例时走(父级)默认逻辑所需的参数

* @param clientFactory 请求不到目标实例时走(父级)默认逻辑所需的参数

* @return Mono<Response<ServiceInstance>>

*/

Mono<Response<ServiceInstance>> choose(String serviceId, ServerHttpRequest request, ServerWebExchange exchange, LoadBalancerClientFactory clientFactory);

}

3、灰度过滤器

过滤器主要是重写选择实例的策略

import com.digital.cnzz.gateway.service.GrayLoadBalancer;

import lombok.extern.slf4j.Slf4j;

import org.apache.http.util.Asserts;

import org.springframework.cloud.client.ServiceInstance;

import org.springframework.cloud.client.loadbalancer.LoadBalancerUriTools;

import org.springframework.cloud.client.loadbalancer.reactive.Response;

import org.springframework.cloud.gateway.config.LoadBalancerProperties;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;

import org.springframework.cloud.gateway.filter.ReactiveLoadBalancerClientFilter;

import org.springframework.cloud.gateway.support.DelegatingServiceInstance;

import org.springframework.cloud.gateway.support.NotFoundException;

import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;

import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;

import org.springframework.stereotype.Component;

import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Mono;

import java.net.URI;

/**

* @author xf

* @Title:

* @Description:

* @date 2023/1/12 17:16

*/

@Slf4j

@Component

public class GrayReactiveLoadBalancerClientFilter extends ReactiveLoadBalancerClientFilter {

private final static String SCHEME = "lb";

private static final int LOAD_BALANCER_CLIENT_FILTER_ORDER = 10150;

private final GrayLoadBalancer grayLoadBalancer;

private LoadBalancerProperties loadBalancerProperties;

private final LoadBalancerClientFactory clientFactory;

public GrayReactiveLoadBalancerClientFilter(LoadBalancerClientFactory clientFactory, LoadBalancerProperties loadBalancerProperties, GrayLoadBalancer grayLoadBalancer) {

super(clientFactory, loadBalancerProperties);

this.loadBalancerProperties = loadBalancerProperties;

this.clientFactory = clientFactory;

this.grayLoadBalancer = grayLoadBalancer;

}

@Override

public int getOrder() {

return LOAD_BALANCER_CLIENT_FILTER_ORDER;

}

@Override

public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

URI url = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);

String schemePrefix = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR);

// 直接放行

if (url == null || (!SCHEME.equals(url.getScheme()) && !SCHEME.equals(schemePrefix))) {

return chain.filter(exchange);

}

// 保留原始url

ServerWebExchangeUtils.addOriginalRequestUrl(exchange, url);

if (log.isTraceEnabled()) {

log.trace(ReactiveLoadBalancerClientFilter.class.getSimpleName() + " url before: " + url);

}

return choose(exchange).doOnNext(response -> {

if (!response.hasServer()) {

throw NotFoundException.create(loadBalancerProperties.isUse404(),

"Unable to find instance for " + url.getHost());

}

URI uri = exchange.getRequest().getURI();

// if the `lb:<scheme>` mechanism was used, use `<scheme>` as the default,

// if the loadbalancer doesn't provide one.

String overrideScheme = null;

if (schemePrefix != null) {

overrideScheme = url.getScheme();

}

DelegatingServiceInstance serviceInstance = new DelegatingServiceInstance(response.getServer(),

overrideScheme);

URI requestUrl = LoadBalancerUriTools.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));

}

/**

* 获取实例

* @param exchange ServerWebExchange

* @return ServiceInstance

*/

private Mono<Response<ServiceInstance>> choose(ServerWebExchange exchange) {

URI uri = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);

Asserts.notNull(uri, "uri");

return grayLoadBalancer.choose(uri.getHost(), exchange.getRequest(),exchange,clientFactory);

}

}

4、基于客户端版本号灰度路由

import cn.hutool.core.collection.CollUtil;

import cn.hutool.core.map.MapUtil;

import cn.hutool.core.util.RandomUtil;

import com.digital.cnzz.gateway.service.GrayLoadBalancer;

import com.github.pagehelper.util.StringUtil;

import lombok.RequiredArgsConstructor;

import lombok.extern.slf4j.Slf4j;

import org.apache.commons.collections4.CollectionUtils;

import org.springframework.cloud.client.ServiceInstance;

import org.springframework.cloud.client.discovery.DiscoveryClient;

import org.springframework.cloud.client.loadbalancer.reactive.DefaultResponse;

import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;

import org.springframework.cloud.client.loadbalancer.reactive.Request;

import org.springframework.cloud.client.loadbalancer.reactive.Response;

import org.springframework.cloud.gateway.support.NotFoundException;

import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;

import org.springframework.cloud.loadbalancer.core.ReactorLoadBalancer;

import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;

import org.springframework.http.server.reactive.ServerHttpRequest;

import org.springframework.stereotype.Component;

import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Mono;

import java.net.URI;

import java.util.List;

import java.util.stream.Collectors;

/**

* @author xf

* @Title:

* @Description:

* @date 2023/1/12 17:18

*/

@Slf4j

@RequiredArgsConstructor

@Component

public class VersionGrayLoadBalancer implements GrayLoadBalancer {

private final DiscoveryClient discoveryClient;

/**

* 根据serviceId 筛选可用服务

* @param serviceId 服务ID

* @param request 当前请求

* @param exchange 请求不到目标实例时走(父级)默认逻辑所需的参数

* @param clientFactory 请求不到目标实例时走(父级)默认逻辑所需的参数

* @return return Mono<Response<ServiceInstance>>

*/

@Override

public Mono<Response<ServiceInstance>> choose(String serviceId, ServerHttpRequest request, ServerWebExchange exchange, LoadBalancerClientFactory clientFactory) {

List<ServiceInstance> instances = discoveryClient.getInstances(serviceId);

// 注册中心无实例 抛出异常

if (CollectionUtils.isEmpty(instances)) {

log.warn("No instance available for {}", serviceId);

throw new NotFoundException("No instance available for " + serviceId);

}

// 获取请求version无则调用父类的策略调用可用实例

String reqVersion = request.getHeaders().getFirst("VERSION");

if (StringUtil.isEmpty(reqVersion)) {

//走父级默认负载均衡策略

return chooseSuper(exchange,clientFactory);

}

// 遍历可以实例元数据若匹配则返回此实例

List<ServiceInstance> availableList = instances.stream()

.filter(instance -> reqVersion

.equalsIgnoreCase(MapUtil.getStr(instance.getMetadata(), "VERSION")))

.collect(Collectors.toList());

if (CollUtil.isEmpty(availableList)) {

//走父级默认负载均衡策略

return chooseSuper(exchange,clientFactory);

}

return Mono.just(new DefaultResponse(availableList.get(RandomUtil.randomInt(availableList.size()))));

}

public Mono<Response<ServiceInstance>> chooseSuper(ServerWebExchange exchange, LoadBalancerClientFactory clientFactory) {

//父级逻辑具体实现可参考 org.springframework.cloud.gateway.filter.ReactiveLoadBalancerClientFilter.choose 方法

URI uri = (URI)exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);

ReactorLoadBalancer<ServiceInstance> loadBalancer = (ReactorLoadBalancer)clientFactory.getInstance(uri.getHost(), ReactorLoadBalancer.class, new Class[]{ServiceInstance.class});

if (loadBalancer == null) {

throw new NotFoundException("No loadbalancer available for " + uri.getHost());

} else {

return loadBalancer.choose(this.createRequest());

}

}

private Request createRequest() {

return ReactiveLoadBalancer.REQUEST;

}

}

5、改造前端代码请求头Request Headers加版本号信息