spring cloud gateway + nacos 灰度发布

spring cloud gateway + nacos 灰度发布

原理

• 在客户端请求时的 header 带入 一个标签，如: svc_version
• 服务器应用 启动的时候 打上标签，可以和客户端的属性一致，如 svc_version
• 请求到网关的时候，网关负载过滤带 svc_version 属性的服务器应用列表
• 返回已经匹配客户端 svc_version 的服务器应用 列表
• 在这些列表中请求转发客户端请求

应用列表

• nacos-user : 普通应用
• nacos-gateway

nacos-gateway

引入依赖

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-actuatorartifactId>
dependency>
<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-bootstrapartifactId>
dependency>
<dependency>
    <groupId>com.alibaba.cloudgroupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-configartifactId>
dependency>
<dependency>
    <groupId>com.alibaba.cloudgroupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-netflix-ribbonartifactId>
        exclusion>
    exclusions>
dependency>
<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-gatewayartifactId>
dependency>

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-testartifactId>
    <scope>testscope>
dependency>
<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-loadbalancerartifactId>
dependency>

注意一定要引入 spring-cloud-loadbalancer!!

实现 灰度负载LoadBalancer

public class GreyRoundRobinLoadBalancer implements ReactorServiceInstanceLoadBalancer {

	private static final String GREP_HEADER = "svc_version";

	private static final Log log = LogFactory.getLog(GreyRoundRobinLoadBalancer.class);

	final AtomicInteger position;

	final String serviceId;

	ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider;

	/**
	 * @param serviceInstanceListSupplierProvider a provider of
	 * {@link ServiceInstanceListSupplier} that will be used to get available instances
	 * @param serviceId id of the service for which to choose an instance
	 */
	public GreyRoundRobinLoadBalancer(ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider,
                                      String serviceId) {
		this(serviceInstanceListSupplierProvider, serviceId, new Random().nextInt(1000));
	}

	/**
	 * @param serviceInstanceListSupplierProvider a provider of
	 * {@link ServiceInstanceListSupplier} that will be used to get available instances
	 * @param serviceId id of the service for which to choose an instance
	 * @param seedPosition Round Robin element position marker
	 */
	public GreyRoundRobinLoadBalancer(ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider,
                                      String serviceId, int seedPosition) {
		this.serviceId = serviceId;
		this.serviceInstanceListSupplierProvider = serviceInstanceListSupplierProvider;
		this.position = new AtomicInteger(seedPosition);
	}

	@SuppressWarnings("rawtypes")
	@Override
	public Mono<Response<ServiceInstance>> choose(Request request) {
		ServiceInstanceListSupplier supplier = serviceInstanceListSupplierProvider
				.getIfAvailable(NoopServiceInstanceListSupplier::new);
		return supplier.get(request)
				.flatMap(list -> {
					RequestDataContext context = (RequestDataContext) request.getContext();
					String version  = context.getClientRequest().getHeaders().getFirst(GREP_HEADER);
					boolean b = StringUtils.hasText(version) ? true : false;
					List<ServiceInstance> collect = list.stream().filter(instance -> {
						if (b) {
							return instance.getMetadata().containsKey(GREP_HEADER) && instance.getMetadata().get(GREP_HEADER).equals(version);
						}
						return !instance.getMetadata().containsKey(GREP_HEADER);
					}).collect(Collectors.toList());
					return Mono.justOrEmpty(collect);
				})
				.next()
				.map(serviceInstances -> processInstanceResponse(supplier, serviceInstances));
	}

	private Response<ServiceInstance> processInstanceResponse(ServiceInstanceListSupplier supplier,
			List<ServiceInstance> serviceInstances) {
		Response<ServiceInstance> serviceInstanceResponse = getInstanceResponse(serviceInstances);
		if (supplier instanceof SelectedInstanceCallback && serviceInstanceResponse.hasServer()) {
			((SelectedInstanceCallback) supplier).selectedServiceInstance(serviceInstanceResponse.getServer());
		}
		return serviceInstanceResponse;
	}

	private Response<ServiceInstance> getInstanceResponse(List<ServiceInstance> instances) {
		if (instances.isEmpty()) {
			if (log.isWarnEnabled()) {
				log.warn("No servers available for service: " + serviceId);
			}
			return new EmptyResponse();
		}

		// Ignore the sign bit, this allows pos to loop sequentially from 0 to
		// Integer.MAX_VALUE
		int pos = this.position.incrementAndGet() & Integer.MAX_VALUE;

		ServiceInstance instance = instances.get(pos % instances.size());

		return new DefaultResponse(instance);
	}

}

配置

@Configuration(proxyBeanMethods = false)
@ConditionalOnDiscoveryEnabled
public class GreyLoadBalancerClientConfiguration {

    private static final int REACTIVE_SERVICE_INSTANCE_SUPPLIER_ORDER = 173827465;

    @Bean
//    @Order(REACTIVE_SERVICE_INSTANCE_SUPPLIER_ORDER)
    public ReactorLoadBalancer<ServiceInstance> greyLoadBalancer(Environment environment,
                                                                 LoadBalancerClientFactory loadBalancerClientFactory) {
        String name = environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
        return new GreyRoundRobinLoadBalancer(
                loadBalancerClientFactory.getLazyProvider(name, ServiceInstanceListSupplier.class), name);
    }

}

向容器注入自定义 LoadBalancer:

@Configuration
@LoadBalancerClients(defaultConfiguration = GreyLoadBalancerClientConfiguration.class)
public class CusLoadBalancerClientConfiguration {

}

@LoadBalancerClients, 重要！！，给所有的负载都加上自定义的灰度负载器

使用

启用应用nacos-user, 一个打了标签，一个没有打标签:

在客户端请求网关时，headers带上 svc_version=1.0, 那么请求就会打到 5558这个应用

参考 nacos loadbalancer:

@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnLoadBalancerNacos
@ConditionalOnNacosDiscoveryEnabled
@LoadBalancerClients(defaultConfiguration = NacosLoadBalancerClientConfiguration.class)
public class LoadBalancerNacosAutoConfiguration {

}

good luck!