实现Kong的Java管理API - Kong最佳实践

Kong提供了Http的管理API，可以实现对Kong的管理。我们利用Kong的Amin API，实现一套JAVA的管理API。这里以添加一个Service和Route为示例：

使用retrofit2实现

添加Maven依赖

<dependency>
            <groupId>com.squareup.retrofit2</groupId>
            <artifactId>retrofit</artifactId>
            <version>${retrofit.version}</version>
        </dependency>
        <dependency>
            <groupId>com.squareup.retrofit2</groupId>
            <artifactId>converter-gson</artifactId>
            <version>${retrofit.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>com.google.code.gson</groupId>
                    <artifactId>gson</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.1</version>
        </dependency>

实现kong客户端的架子

添加Kong客户端

@Data
public class KongClient {
 
    private ServiceService serviceService;
    private RouteService routeService;
 
    public KongClient(String adminUrl) {
 
        if (adminUrl == null || adminUrl.isEmpty()) {
            throw new IllegalArgumentException("The adminUrl cannot be null or empty!");
        }
        RetrofitServiceCreator retrofitServiceCreatorForAdminUrl = new RetrofitServiceCreator(adminUrl);
        {
            serviceService = retrofitServiceCreatorForAdminUrl.create(ServiceService.class,RetrofitServiceService.class);
            routeService = retrofitServiceCreatorForAdminUrl.create(RouteService.class,RetrofitRouteService.class);
        }
  }
}

添加Retrofit处理类

public class RetrofitServiceCreator {
 
    private Retrofit retrofit;
 
 
    // -------------------------------------------------------------------
 
    public RetrofitServiceCreator(String baseUrl) {
 
        retrofit = new Retrofit.Builder()
                .baseUrl(baseUrl)
                .client(initOkHttpClient(baseUrl.toLowerCase().startsWith("https"))) // support https
                .addConverterFactory(CustomGsonConverterFactory.create()) // replace GsonConverterFactory
 
    }
 
    // -------------------------------------------------------------------
 
    @SuppressWarnings("unchecked")
    public <T> T create(Class<T> serviceInterface, Class<?> retrofitServiceInterface) {
        Object proxied = retrofit.create(retrofitServiceInterface);
        return (T) Proxy.newProxyInstance(
                RetrofitServiceCreator.class.getClassLoader(),
                new Class[] { serviceInterface },
                new RetrofitBodyExtractorInvocationHandler(proxied));
    }
 
    public <T> T createRetrofitService(Class<T> retrofitServiceInterface) {
        return retrofit.create(retrofitServiceInterface);
    }
 
    // -------------------------------------------------------------------
 
    private OkHttpClient initOkHttpClient(boolean supportHttps) {
 
        if(supportHttps) {
            HttpsUtil.SSLParams sslParams = HttpsUtil.getSslSocketFactory(null, null, null);
            OkHttpClient okHttpClient = new OkHttpClient.Builder()
                    .sslSocketFactory(sslParams.sSLSocketFactory, sslParams.trustManager)
                    .build();
            return okHttpClient;
        }
 
        return new OkHttpClient.Builder().build();
    }
}

添加动态代理处理类

@Slf4j
public class RetrofitBodyExtractorInvocationHandler implements InvocationHandler {
 
    private Object proxied;
 
    public RetrofitBodyExtractorInvocationHandler(Object proxied) {
        this.proxied = proxied;
    }
 
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        String methodName = method.getName();
        Class<?>[] parameterTypes = method.getParameterTypes();
        Method method1 = proxied.getClass().getMethod(methodName, parameterTypes);
        Call call = (Call) method1.invoke(proxied, args);
        Response response = call.execute();
        log.debug("Http Request:  " + response.raw().request());
        log.debug("Http Response: " + response.raw().toString());
        if(!response.isSuccessful()) {
            throw new KongClientException(response.errorBody() != null ? response.errorBody().string() : String.valueOf(response.code()));
        }
        return response.body();
    }
}

添加自定义JSON转换工厂

class CustomGsonConverterFactory extends Converter.Factory {
 
    private final Gson gson;
 
    private CustomGsonConverterFactory(Gson gson) {
        if (gson == null) throw new NullPointerException("gson == null");
        this.gson = gson;
    }
 
    public static CustomGsonConverterFactory create() {
        return create(new Gson());
    }
 
    public static CustomGsonConverterFactory create(Gson gson) {
        return new CustomGsonConverterFactory(gson);
    }
 
    @Override
    public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {
        TypeAdapter<?> adapter = gson.getAdapter(TypeToken.get(type));
        return new CustomGsonResponseBodyConverter<>(gson, adapter);
    }
 
    @Override
    public Converter<?, RequestBody> requestBodyConverter(Type type,Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) {
        TypeAdapter<?> adapter = gson.getAdapter(TypeToken.get(type));
        return new CustomGsonRequestBodyConverter<>(gson, adapter);
    }
}

实现Service的Java Admin API

添加Service实体

@Data @Builder
public class Service {
 
    private String id;
    private String name;
    private String protocol;
    private String host;
    private Integer port;
    private String path;
    private String url;
    private Integer retries;
    @SerializedName("connect_timeout")
    private Long connectTimeout;
    @SerializedName("read_timeout")
    private Long readTimeout;
    @SerializedName("write_timeout")
    private Long writeTimeout;
    @SerializedName("created_at")
    private Long createdAt;
    @SerializedName("updated_at")
    private Long updatedAt;
}

添加Service接口，这里只要删除和新增

public interface ServiceService {
 
    Service addService(Service service);
    void deleteService(String nameOrId);
}

添加Retrofit的处理接口

public interface RetrofitServiceService {
 
    @POST("services/")
    Call<Service> addService(@Body Service request);
    @DELETE("services/{nameOrId}")
    Call<Void> deleteService(@Path("nameOrId") String nameOrId);
}

实现Route的Java Admin API

添加Route实体

@Data @Builder
public class Route {
 
    private String id;
    private List<String> protocols;
    private List<String> methods;
    private List<String> hosts;
    private List<String> paths;
    @SerializedName("strip_path")
    private Boolean stripPath;
    @SerializedName("preserve_host")
    private Boolean preserveHost;
    private Service  service;
    @SerializedName("created_at")
    private Long createdAt;
    @SerializedName("updated_at")
    private Long updatedAt;
}

添加Route接口，这里只要删除和新增

public interface RouteService {
 
    Route addRoute(Route route);
    void DeleteRoute(String id);
}

添加Retrofit的处理接口

public interface RetrofitRouteService {
    @POST("routes/")
    Call<Route> addRoute(@Body Route route);
    @DELETE("routes/{id}")
    Call<Void> DeleteRoute(@Path("id") String id);
}

单元测试一下

新建一个名字为example-service，地址为http://mockbin.org的Service。并为Service添加host为example.com的Route路由。

public class ServiceRouteTest extends BaseTest {
 
    public static final String EXAMPLE_SERVICE = "example-service";
 
    @Test
    public void createServiceAndRouteTest(){
 
        // 删除Route和Service
        CommonList<Route> commonList = kongClient.getRouteService().listRoutesByService(EXAMPLE_SERVICE);
        List<Route> routeList = commonList.getData();
        if(null!=routeList && routeList.size()>0 ){
            for (Route route : routeList) {
                kongClient.getRouteService().DeleteRoute(route.getId());
            }
        }
        kongClient.getServiceService().deleteService(EXAMPLE_SERVICE);
 
 
        // 新建Service和Route
        Service service = Service.builder().url("http://mockbin.org").name(EXAMPLE_SERVICE).build();
        Service response4service = kongClient.getServiceService().addService(service);
        printJson(response4service);
        List<String> hostList = new ArrayList<>();
        hostList.add("example.com");
        Route route = Route.builder().hosts(hostList).service(Service.builder().id(response4service.getId()).build()).build();
        Route response4route = kongClient.getRouteService().addRoute(route);
        printJson(response4route);
    }
 
}

最后，检查下效果

使用GET方法，访问地址http://192.168.56.112:8000，并添加在头部添加host[]=example.com，结果如下：

写在最后

• 利用架子可以自定义其他Kong的JAVA客户端。
• 很多时候，我们的API地址是通过程序扫描出来的，或者管理系统进行配置的。这个时候，我们就可以利用Kong的JAVA客户端快速的实现Kong的接口管理，轮训等。
• 应用降级，流控，金丝雀，灰度等等，都可以通过Kong的JAVA客户端轻松实现。