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

[/code]

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;
}
}

访问需要在header上指定tag

doc

Spring Cloud: Ribbon dynamic routing