spring-cloud-gateway動態路由的實現方法

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概述

線上項目發佈一般有以下幾種方案:

  • 機發佈
  • 藍綠部署
  • 滾動部署
  • 灰度發佈

停機發佈 這種發佈一般在夜裡或者進行大版本升級的時候發佈，因為需要停機，所以現在大傢都在研究 Devops 方案。

藍綠部署 需要準備兩個相同的環境。一個環境新版本，一個環境舊版本，通過負載均衡進行切換與回滾，目的是為瞭減少服務停止時間。

滾動部署 就是在升級過程中，並不一下子啟動所有新版本，是先啟動一臺新版本，再停止一臺老版本，然後再啟動一臺新版本，再停止一臺老版本，直到升級完成。基於 k8s 的升級方案默認就是滾動部署。

灰度發佈 也叫金絲雀發佈，灰度發佈中，常常按照用戶設置路由權重，例如 90%的用戶維持使用老版本，10%的用戶嘗鮮新版本。不同版本應用共存，經常與 A/B 測試一起使用，用於測試選擇多種方案。

上邊介紹的幾種發佈方案，主要是引出我們接下來介紹的 spring-cloud-gateway 動態路由，我們可以基於動態路由、負載均衡和策略加載去實現 灰度發佈。當然現在有很多開源的框架可以實現 灰度發佈，這裡隻是研究學習。

動態路由

spring-cloud-gateway 默認將路由加載在內存中。具體可以參見 InMemoryRouteDefinitionRepository 類的實現。

這裡我們基於 Redis 實現動態路由。基礎項目見 spring-cloud-gateway 簡介

1. 將 actuator 的端點暴露出來。

management:
 endpoints:
  web:
   exposure:
    include: "*"

2. redis 配置

@Configuration
public class RedisConfig {

  @Bean(name = {"redisTemplate", "stringRedisTemplate"})
  public StringRedisTemplate stringRedisTemplate(RedisConnectionFactory factory) {
    StringRedisTemplate redisTemplate = new StringRedisTemplate();
    redisTemplate.setConnectionFactory(factory);
    return redisTemplate;
  }

}

3. 將原內存路由持久化到 redis

@Component
public class RedisRouteDefinitionRepository implements RouteDefinitionRepository {

  /**
   * hash存儲的key
   */
  public static final String GATEWAY_ROUTES = "gateway_dynamic_route";

  @Resource
  private StringRedisTemplate redisTemplate;

  /**
   * 獲取路由信息
   * @return
   */
  @Override
  public Flux<RouteDefinition> getRouteDefinitions() {
    List<RouteDefinition> routeDefinitions = new ArrayList<>();
    redisTemplate.opsForHash().values(GATEWAY_ROUTES).stream()
        .forEach(routeDefinition -> routeDefinitions.add(JSON.parseObject(routeDefinition.toString(), RouteDefinition.class)));
    return Flux.fromIterable(routeDefinitions);
  }

  @Override
  public Mono<Void> save(Mono<RouteDefinition> route) {
    return route.flatMap(routeDefinition -> {
      redisTemplate.opsForHash().put(GATEWAY_ROUTES, routeDefinition.getId(), JSONObject.toJSONString(routeDefinition));
      return Mono.empty();
    });
  }

  @Override
  public Mono<Void> delete(Mono<String> routeId) {
    return routeId.flatMap(id -> {
      if (redisTemplate.opsForHash().hasKey(GATEWAY_ROUTES, id)) {
        redisTemplate.opsForHash().delete(GATEWAY_ROUTES, id);
        return Mono.empty();
      }
      return Mono.defer(() -> Mono.error(new NotFoundException("route definition is not found, routeId:" + routeId)));
    });
  }

}

4. 重寫動態路由服務

@Service
public class GatewayDynamicRouteService implements ApplicationEventPublisherAware {

  @Resource
  private RedisRouteDefinitionRepository redisRouteDefinitionRepository;

  private ApplicationEventPublisher applicationEventPublisher;

  /**
   * 增加路由
   * @param routeDefinition
   * @return
   */
  public int add(RouteDefinition routeDefinition) {
    redisRouteDefinitionRepository.save(Mono.just(routeDefinition)).subscribe();
    applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this));
    return 1;
  }

  /**
   * 更新
   * @param routeDefinition
   * @return
   */
  public int update(RouteDefinition routeDefinition) {
    redisRouteDefinitionRepository.delete(Mono.just(routeDefinition.getId()));
    redisRouteDefinitionRepository.save(Mono.just(routeDefinition)).subscribe();
    applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this));
    return 1;
  }

  /**
   * 刪除
   * @param id
   * @return
   */
  public Mono<ResponseEntity<Object>> delete(String id) {
    return redisRouteDefinitionRepository.delete(Mono.just(id)).then(Mono.defer(() -> Mono.just(ResponseEntity.ok().build())))
        .onErrorResume(t -> t instanceof NotFoundException, t -> Mono.just(ResponseEntity.notFound().build()));
  }


  @Override
  public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
    this.applicationEventPublisher = applicationEventPublisher;
  }
}

5. 對外暴露接口

@RestController
@RequestMapping("/gateway")
public class GatewayDynamicRouteController {

  @Resource
  private GatewayDynamicRouteService gatewayDynamicRouteService;

  @PostMapping("/add")
  public String create(@RequestBody RouteDefinition entity) {
    int result = gatewayDynamicRouteService.add(entity);
    return String.valueOf(result);
  }

  @PostMapping("/update")
  public String update(@RequestBody RouteDefinition entity) {
    int result = gatewayDynamicRouteService.update(entity);
    return String.valueOf(result);
  }

  @DeleteMapping("/delete/{id}")
  public Mono<ResponseEntity<Object>> delete(@PathVariable String id) {
    return gatewayDynamicRouteService.delete(id);
  }

}

測試

測試前刪除我們配置的靜態路由，因為靜態路由和 redis 動態路由同時存在時取並集。

訪問 http://localhost:2000/actuator/gateway/routes , 可以看到隻有默認路由。

[
  {
    "route_id": "CompositeDiscoveryClient_consul",
    "route_definition": {
      "id": "CompositeDiscoveryClient_consul",
      "predicates": [
        {
          "name": "Path",
          "args": {
            "pattern": "/consul/**"
          }
        }
      ],
      "filters": [
        {
          "name": "RewritePath",
          "args": {
            "regexp": "/consul/(?<remaining>.*)",
            "replacement": "/${remaining}"
          }
        }
      ],
      "uri": "lb://consul",
      "order": 0
    },
    "order": 0
  },
  {
    "route_id": "CompositeDiscoveryClient_idc-gateway",
    "route_definition": {
      "id": "CompositeDiscoveryClient_idc-gateway",
      "predicates": [
        {
          "name": "Path",
          "args": {
            "pattern": "/idc-gateway/**"
          }
        }
      ],
      "filters": [
        {
          "name": "RewritePath",
          "args": {
            "regexp": "/idc-gateway/(?<remaining>.*)",
            "replacement": "/${remaining}"
          }
        }
      ],
      "uri": "lb://idc-gateway",
      "order": 0
    },
    "order": 0
  },
  {
    "route_id": "CompositeDiscoveryClient_idc-provider1",
    "route_definition": {
      "id": "CompositeDiscoveryClient_idc-provider1",
      "predicates": [
        {
          "name": "Path",
          "args": {
            "pattern": "/idc-provider1/**"
          }
        }
      ],
      "filters": [
        {
          "name": "RewritePath",
          "args": {
            "regexp": "/idc-provider1/(?<remaining>.*)",
            "replacement": "/${remaining}"
          }
        }
      ],
      "uri": "lb://idc-provider1",
      "order": 0
    },
    "order": 0
  },
  {
    "route_id": "CompositeDiscoveryClient_idc-provider2",
    "route_definition": {
      "id": "CompositeDiscoveryClient_idc-provider2",
      "predicates": [
        {
          "name": "Path",
          "args": {
            "pattern": "/idc-provider2/**"
          }
        }
      ],
      "filters": [
        {
          "name": "RewritePath",
          "args": {
            "regexp": "/idc-provider2/(?<remaining>.*)",
            "replacement": "/${remaining}"
          }
        }
      ],
      "uri": "lb://idc-provider2",
      "order": 0
    },
    "order": 0
  }
]

這個時候訪問 http://192.168.124.5:2000/idc-provider1/provider1/1 根據結果可以推測能正確路由到 provider1， 測試結果一致。

創建 provider1 路由，將路徑設置為 /p1/**，測試是否生效。

POST 請求 http://localhost:2000/gateway/add

{
  "id":"provider1",
  "predicates":[
   {
     "name":"Path",
     "args":{
      "_genkey_0":"/p1/**"
     }
   },
   {
     "name":"RemoteAddr",
     "args":{
      "_genkey_0":"192.168.124.5/16"
     }
   }
  ],
  "filters":[
   {
     "name":"StripPrefix",
     "args":{
      "_genkey_0":"1"
     }
   }
  ],
  "uri":"lb://idc-provider1",
  "order":0
}

查看 redis 存儲，或者請求 http://localhost:2000/actuator/gateway/routes , 都可以看到配置成功。

訪問

curl http://localhost:2000/p1/provider1/1

結果輸出 2001，與期望一致。

由此可見動態路由已經生效。

到此這篇關於spring-cloud-gateway動態路由的實現方法的文章就介紹到這瞭,更多相關spring-cloud-gateway動態路由內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet！

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