使用OpenFeign在HATEOAS资源上保留主机名

Question

我试图使用OpenFeign和ResourceAssembler将URI添加到位于其他微服务中的资源，同时保留原始请求中的主机名。

当对另一个微服务中的HATEOAS资源发出REST请求时，resource.getId（）方法将返回一个链接，其中主机名是Docker容器哈希，而不是用于发出请求的原始主机名。

控制器

@RestController
@RequestMapping("/bulletins")
public class BulletinController {
// Autowired dependencies

    @GetMapping(produces = MediaTypes.HAL_JSON_VALUE)
    public ResponseEntity<PagedResources<BulletinResource>> getBulletins(Pageable pageable) {
        Page<Bulletin> bulletins = bulletinRepository.findAll(pageable);

        return ResponseEntity.ok(pagedResourceAssembler.toResource(bulletins, bulletinResourceAssembler));
    }
}

汇编器

@Component
public class BulletinResourceAssembler extends ResourceAssemblerSupport<Bulletin, BulletinResource> {
    private final AdministrationService administrationService;

    @Autowired
    public BulletinResourceAssembler(AdministrationService administrationService) {
        super(BulletinController.class, BulletinResource.class);
        this.administrationService = administrationService;
    }

    @Override
    public BulletinResource toResource(Bulletin entity) {
        Resource<Site> siteRessource = administrationService.getSiteBySiteCode(entity.getSiteCode());

        \\ Set other fields ...

        bulletinRessource.add(siteRessource.getId().withRel("site"));
        return bulletinRessource;
    }
}

假客户

@FeignClient(name = "${feign.administration.serviceId}", path = "/api")
public interface AdministrationService {

    @GetMapping(value = "/sites/{siteCode}")
    Resource<Site> getSiteBySiteCode(@PathVariable("siteCode") String siteCode);

}

公告资源

@Data
public class BulletinResource extends ResourceSupport {
// fields
}

预期结果
卷曲http://myhost/api/bulletins

{
  "_embedded" : {
    "bulletinResources" : [ {
      "entityId" : 1,
      "_links" : {
        "self" : {
          "href" : "http://myhost/api/bulletins/1"
        },
        "site" : {
          "href" : "http://myhost/api/sites/000"
        }
      }
    } ]
  },
  [...]
}

实际结果
卷曲http://myhost/api/bulletins

{
  "_embedded" : {
    "bulletinResources" : [ {
      "entityId" : 1,
      "_links" : {
        "self" : {
          "href" : "http://myhost/api/bulletins/1"
        },
        "site" : {
          "href" : "http://b4dc1a02586c:8080/api/sites/000"
        }
      }
    } ]
  },
  [...]
}

请注意，站点href为b4dc1a02586c，这是Docker容器ID。

Answer 1

解决方案是手动为FeignClient定义一个RequestInterceptor，并手动添加X-Forwarded-Host标头，并在向其发出请求的服务中定义ForwardedHeaderFilter bean。

客户端

public class ForwardHostRequestInterceptor implements RequestInterceptor {

    private static final String HOST_HEADER = "Host";
    private static final String X_FORWARDED_HOST = "X-Forwarded-Host";

    @Override
    public void apply(RequestTemplate requestTemplate) {
        ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder
                .getRequestAttributes();

        if (requestAttributes == null) {
            return;
        }

        HttpServletRequest request = requestAttributes.getRequest();
        String host = request.getHeader(X_FORWARDED_HOST);
        if (host == null) {
            host = request.getHeader(HOST_HEADER);
        }

        requestTemplate.header(X_FORWARDED_HOST, host);
    }

}

生产方

生产者方面还需要根据有关讨论进行修改
https://github.com/spring-projects/spring-hateoas/issues/862
指的是以下文档
https://docs.spring.io/spring-hateoas/docs/current-SNAPSHOT/reference/html/#server.link-builder.forwarded-headers
指出要添加以下bean以便使用转发头。

@Bean
ForwardedHeaderFilter forwardedHeaderFilter() {
    return new ForwardedHeaderFilter();
}