Spring Cloud Gray 接入开发指南

工程模块

功能模块

示例模块

灰度决策

灰度决策是灰度路由的关键，灰度决策由工厂类创建，工厂类的抽象接口是cn.springcloud.gray.decision.factory.GrayDecisionFactory

默认灰度决策实现

目前已有的灰度决策有：

自定义灰度决策实现

如果上面这些决策还不能满足需求，那么可以扩展cn.springcloud.gray.decision.factory.GrayDecisionFactory，实现自定义的逻辑，发布到Spring容器中即可。如:

import cn.springcloud.gray.decision.GrayDecision;
import cn.springcloud.gray.decision.factory.AbstractGrayDecisionFactory;
import cn.springcloud.gray.request.GrayHttpTrackInfo;
import lombok.Getter;
import lombok.Setter;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;

@Component
public class VersionGrayDecisionFactory extends AbstractGrayDecisionFactory<VersionGrayDecisionFactory.Config> {

    public VersionGrayDecisionFactory() {
        super(VersionGrayDecisionFactory.Config.class);
    }

    @Override
    public GrayDecision apply(Config configBean) {
        return args -> {
            GrayHttpTrackInfo grayRequest = (GrayHttpTrackInfo) args.getGrayRequest().getGrayTrackInfo();
           int version = StringUtils.defaultIfNull(grayRequest.getAttribute(USER_ID_PARAM_NAME), "0");
            if(StringUtils.equal(configBean.getCompareMode(), "LT")){
                return configBean.getVersion() > version;
            }else if(StringUtils.equal(configBean.getCompareMode(), "GT")){
                return configBean.getVersion() < version;
            }else{
                return configBean.getVersion() == version;
            }
        };
    }

    @Setter
    @Getter
    public static class Config {
        private String compareMode;
        private int varsion;
    }
}

灰度追踪

灰度追踪记录的逻辑是由cn.springcloud.gray.request.GrayInfoTracker的实现类实现

默认灰度追踪

目前已有的灰度追踪有:

自定义灰度追踪实现

如果上面这些决策还不能满足需求，那么可以扩展cn.springcloud.gray.request.GrayInfoTracker，实现自定义的逻辑，发布到Spring容器中即可。如:

import cn.springcloud.gray.request.GrayHttpTrackInfo;
import cn.springcloud.gray.request.TrackArgs;
import cn.springcloud.gray.web.tracker.HttpGrayInfoTracker;
import lombok.extern.slf4j.Slf4j;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;

@Slf4j
@Component
public class UserIdGrayInfoTracker implements HttpGrayInfoTracker {

    @Override
    public void call(TrackArgs<GrayHttpTrackInfo, HttpServletRequest> args) {
        SecurityContext securityContext = SecurityContextHolder.getContext();
        Authentication authentication = securityContext.getAuthentication();
        String userId = null;
        if (authentication.getPrincipal() instanceof UserDetails) {
            UserDetails springSecurityUser = (UserDetails) authentication.getPrincipal();
            userId = springSecurityUser.getUsername();
        } else if (authentication.getPrincipal() instanceof String) {
            userId = (String) authentication.getPrincipal();
        }
        args.getTrackInfo().setAttribute("userId", userId);
    }
}

项目扩展

项目已经实现了灰度的内核，如果要与其它的注册中心或者负载均衡中间件集成，只需实现相应的plugin即可，Spring Cloud Gray已经提供了Eureka、Ribbon、Feign、Zuul以及Spring Cloud Gateway和Spring Cloud Stream的plugin，添加相应的plugin依赖即可。