SpringCloud Gateway 4动态路由

        配置网关路由一般有两种方式

        application.yml 中配置

1.  
   routes:
2.  
   #路径匹配
3.  
   - id: demo-server
4.  
   uri: lb://demo-server
5.  
   predicates:
6.  
   # 这样写方便后面理解
7.  
   - name: Path
8.  
   args:
9.  
   pattern: /api/hi/**
10.  
    filters:
11.  
    - name: RewritePath
12.  
    args:
13.  
    regexp: /api/(?<segment>.*)
14.  
    replacement: /$\{segment}
15.  
    - AddRequestHeader=X-Request-Foo, Bar

         代码里配置

1.  
   @Bean
2.  
   public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
3.  
   return builder.routes()
4.  
   .route("path_route", r -> r.path("/get")
5.  
   .uri("http://httpbin.org"))
6.  
   .route("host_route", r -> r.host("*.myhost.org")
7.  
   .uri("http://httpbin.org"))
8.  
   .route("rewrite_route", r -> r.host("*.rewrite.org")
9.  
   .filters(f -> f.rewritePath("/foo/(?<segment>.*)", "/${segment}"))
10.  
    .uri("http://httpbin.org"))
11.  
    .route("hystrix_route", r -> r.host("*.hystrix.org")
12.  
    .filters(f -> f.hystrix(c -> c.setName("slowcmd")))
13.  
    .uri("http://httpbin.org"))
14.  
    .route("hystrix_fallback_route", r -> r.host("*.hystrixfallback.org")
15.  
    .filters(f -> f.hystrix(c -> c.setName("slowcmd").setFallbackUri("forward:/hystrixfallback")))
16.  
    .uri("http://httpbin.org"))
17.  
    .route("limit_route", r -> r
18.  
    .host("*.limited.org").and().path("/anything/**")
19.  
    .filters(f -> f.requestRateLimiter(c -> c.setRateLimiter(redisRateLimiter())))
20.  
    .uri("http://httpbin.org"))
21.  
    .build();
22.  
    }

         无论是yml还是代码，这些配置最终都是被封装到 RouteDefinition 对象中。

        我们找到关键类 RouteDefinitionRepository，默认用InMemoryRouteDefinitionRepository。而做动态路由的关键就在这里。

1.  
   @Component
2.  
   public class DynamicRouteDefinitionRepository implements RouteDefinitionRepository, ApplicationEventPublisherAware {
3.  
    
4.  
   @Autowired
5.  
   private GatewayRouteService gatewayRouteService;
6.  
    
7.  
   private ApplicationEventPublisher eventPublisher;
8.  
    
9.  
   private Map<String, RouteDefinition> cache = new ConcurrentHashMap<>();
10.  
     
11.  
    @Override
12.  
    public Flux<RouteDefinition> getRouteDefinitions() {
13.  
    return Flux.fromIterable(cache.values());
14.  
    }
15.  
     
16.  
    @Override
17.  
    public Mono<Void> save(Mono<RouteDefinition> route) {
18.  
    return route.flatMap(
19.  
    routeDefinition -> {
20.  
    gatewayRouteService.save(RouteDefinitionConverter.convertToDTO(routeDefinition));
21.  
    this.addCache(routeDefinition);
22.  
    return Mono.empty();
23.  
    });
24.  
    }
25.  
     
26.  
    @Override
27.  
    public Mono<Void> delete(Mono<String> routeId) {
28.  
    return routeId.flatMap(
29.  
    id -> {
30.  
    gatewayRouteService.remove(id);
31.  
    this.removeCache(id);
32.  
    return Mono.empty();
33.  
    });
34.  
    }
35.  
     
36.  
    @Override
37.  
    public void setApplicationEventPublisher(ApplicationEventPublisher eventPublisher) {
38.  
    this.eventPublisher = eventPublisher;
39.  
    }
40.  
     
41.  
    /**
42.  
    * 将指定路由加入到缓存中。
43.  
    */
44.  
    public void addCache(RouteDefinition route) {
45.  
    this.cache.putIfAbsent(route.getId(), route);
46.  
    this.publishEvent();
47.  
    }
48.  
     
49.  
    /**
50.  
    * 将指定路由从缓存中删除。
51.  
    */
52.  
    public void removeCache(String routeId) {
53.  
    if (this.cache.remove(routeId) != null) {
54.  
    this.publishEvent();
55.  
    }
56.  
    }
57.  
     
58.  
    public void publishEvent() {
59.  
    eventPublisher.publishEvent(new RefreshRoutesEvent(this));
60.  
    }
61.  
     
62.  
    public Map<String, RouteDefinition> getCache() {
63.  
    return cache;
64.  
    }
65.  
     
66.  
    public void setCache(Map<String, RouteDefinition> cache) {
67.  
    this.cache = cache;
68.  
    }
69.  
     
70.  
    public void clearCache() {
71.  
    this.cache.clear();
72.  
    }
73.  
     
74.  
     
75.  
    }

解释一下这边实现的几个关键方法

• getRouteDefinitions
  • 用于返回自定义的路由配置信息，可以从数据库或者缓存中取，自行实现
• save
  • 用于通过 RESTFul API 新增路由信息
  • 需要开启 actuator 的 gateway 端点
• delete
  • 用于通过 RESTFul API 删除路由信息
  • 需要开启 actuator 的 gateway 端点

我这边采用 mysql 来存储配置路由信息，表结构如下

1.  
   SET NAMES utf8mb4;
2.  
   SET FOREIGN_KEY_CHECKS = 0;
3.  
    
4.  
   -- ----------------------------
5.  
   -- Table structure for gateway_route
6.  
   -- ----------------------------
7.  
   DROP TABLE IF EXISTS `gateway_route`;
8.  
   CREATE TABLE `gateway_route` (
9.  
   `id` bigint(0) NOT NULL AUTO_INCREMENT COMMENT '主键',
10.  
    `route_id` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '路由id',
11.  
    `route_order` int(0) NULL DEFAULT 0 COMMENT '路由顺序',
12.  
    `uri` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '路由路径',
13.  
    `is_enable` char(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT 'Y' COMMENT '是否启用',
14.  
    `create_user` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '创建用户',
15.  
    `create_time` datetime(0) NULL DEFAULT NULL COMMENT '创建时间',
16.  
    `update_user` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '更新用户',
17.  
    `update_time` datetime(0) NULL DEFAULT NULL COMMENT '更新时间',
18.  
    `is_delete` char(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT 'N' COMMENT '是否删除',
19.  
    PRIMARY KEY (`id`) USING BTREE
20.  
    ) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = '网关-路由' ROW_FORMAT = Dynamic;
21.  
     
22.  
    -- ----------------------------
23.  
    -- Records of gateway_route
24.  
    -- ----------------------------
25.  
    INSERT INTO `gateway_route` VALUES (1, 'demo-server', 0, 'lb://demo-server', 'Y', 'admin', '2022-01-26 17:23:42', NULL, NULL, 'N');
26.  
     
27.  
    -- ----------------------------
28.  
    -- Table structure for gateway_route_param
29.  
    -- ----------------------------
30.  
    DROP TABLE IF EXISTS `gateway_route_param`;
31.  
    CREATE TABLE `gateway_route_param` (
32.  
    `id` bigint(0) NOT NULL AUTO_INCREMENT COMMENT '主键',
33.  
    `route_id` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '路由id',
34.  
    `param_name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '参数名称',
35.  
    `param_key` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '参数key',
36.  
    `param_value` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '参数value',
37.  
    `type` int(0) NOT NULL COMMENT '1 为predicate，2为 filter',
38.  
    `is_enable` char(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT 'Y' COMMENT '是否生效',
39.  
    `create_user` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '创建用户',
40.  
    `create_time` datetime(0) NULL DEFAULT NULL COMMENT '创建时间',
41.  
    `update_user` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '更新用户',
42.  
    `update_time` datetime(0) NULL DEFAULT NULL COMMENT '更新时间',
43.  
    `is_delete` char(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT 'N' COMMENT '是否删除',
44.  
    PRIMARY KEY (`id`) USING BTREE
45.  
    ) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = '网关-路由参数表' ROW_FORMAT = Dynamic;
46.  
     
47.  
    -- ----------------------------
48.  
    -- Records of gateway_route_param
49.  
    -- ----------------------------
50.  
    INSERT INTO `gateway_route_param` VALUES (1, 'demo-server', 'Path', 'pattern', '/api/hi/**', 1, 'Y', 'admin', '2022-01-26 17:26:07', 'admin', '2022-01-26 17:26:07', 'N');
51.  
    INSERT INTO `gateway_route_param` VALUES (2, 'demo-server', 'RewritePath', 'regexp', '/api/(?<segment>.*)', 2, 'Y', 'admin', '2022-01-26 17:26:32', 'admin', '2022-01-26 17:26:32', 'N');
52.  
    INSERT INTO `gateway_route_param` VALUES (3, 'demo-server', 'RewritePath', 'replacement', '/$\\{segment}', 2, 'Y', 'admin', '2022-02-07 11:10:53', 'admin', '2022-02-07 11:10:53', 'N');

        其中 param 中的 key，value 比较不太好理解，官方文档里也暂没有找到比较完整的示例demo。我这边通过网上资料的简单拼凑，实现了路径重写（RewritePath）的过滤器配置。

       最后贴上源代码

https://github.com/kid626/springcloud-gateway.githttps://github.com/kid626/springcloud-gateway.git

这篇好文章是转载于：学新通技术网