ribbon使用eureka的meta进行动态路由

序

使用eureka的元数据信息，再配上ribbon的路由功能，就可以在api-gateway实现很多功能，比如灰度测试、生产调试等等。下面介绍一下，怎么使用jmnarloch大神提供的ribbon-discovery-filter-spring-cloud-starter，利用简单的几行代码搞定这一切。

maven

        <dependency>
            <groupId>io.jmnarloch</groupId>
            <artifactId>ribbon-discovery-filter-spring-cloud-starter</artifactId>
            <version>2.1.0</version>
        </dependency>

eureka元数据配置

eureka:
  instance:
    metadataMap:
      tag: pre-prod

路由

@Component
public class DynamicRoutesFilter extends ZuulFilter {

    private static final Logger LOGGER = LoggerFactory.getLogger(DynamicRoutesFilter.class);

    @Override
    public String filterType() {
        return "pre";
    }

    @Override
    public int filterOrder() {
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {
        RequestContext requestContext = RequestContext.getCurrentContext();
        HttpServletRequest request = requestContext.getRequest();
        String tag = request.getHeader("tag");
        if(tag != null){
          RibbonFilterContextHolder.getCurrentContext().add("tag", tag);
        }
        return null;
    }
}

doc

• Spring Cloud: Ribbon dynamic routing

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