Spring Cloud Gateway Extra Plugin

• Cache Request Body And Form Body
• Add Request Log Filter To Log Request And Response
• Add Read Json Response Body And Log Response Body
• Add Global Exception Handler With Json
• Add Custom Exception Handler
• Add Grey Route With Ribbon
• Temporary Offline Endpoint

• This Dependency Base Spring Cloud Gateway[Greenwich.SR1],Suggest To Update To This SpringCloud Version,Official Resolve Some Issues , Fix Some Bugs.
• This Dependency Is Now In Maven Central.
• The Feature To Read Request And Response Json Data Will Loss A Lot Of Performance,It Will Reduce The Gateway Traffic.

• 1 . Include Dependency

  Spring Cloud Gateway

  <dependencies>
      <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-gateway</artifactId>
      </dependency>
      <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
      </dependency>
  </dependencies>
  
  <dependencyManagement>
      <dependencies>
          <dependency>
              <groupId>org.springframework.cloud</groupId>
              <artifactId>spring-cloud-dependencies</artifactId>
              <version>Greenwich.SR1</version>
              <type>pom</type>
              <scope>import</scope>
          </dependency>
      </dependencies>
  </dependencyManagement>

  Gateway Plugin

  <dependency>
      <groupId>pro.chenggang</groupId>
      <artifactId>spring-cloud-gateway-plugin</artifactId>
      <version>1.3.2.RELEASE</version>
  </dependency>

• 2 . Add Enable Annotation To You Application

  @EnableGatewayPlugin
  public class SpringCloudGatewayPluginApplication {
  
      public static void main(String[] args) {
          SpringApplication.run(SpringCloudGatewayPluginApplication.class, args);
      }
  
  }

  Note: If You User SpringBoot 2.1.0+,You should set allow-bean-definition-overriding to true

  spring:
    main:
      allow-bean-definition-overriding: true

• 3 . Choose Plugin Feature To Use

  By use this annotation @EnableGatewayPlugin to enable the plugin,the plugin support switch to choose feature By default,the GatewayContext Filter is always into system

  1.0.0.RELEASE,1.1.0.RELEASE Should use annotation method As Below to Choose which plugin function what you want to use.

  public @interface EnableGatewayPlugin {
  
      /**
       * enable request log plugin
       * default true
       * @return
       */
      boolean enableRequestLog() default true;
  
      /**
       * enable grey route plugin
       * default false
       * @return
       */
      boolean enableGreyRoute() default false;
  
      /**
       * grey ribbon Rule
       * @return
       */
      GreyRibbonRule greyRibbonRule() default GreyRibbonRule.DEFAULT;
  
      /**
       * enable json  global exception handler
       * default true
       * @return
       */
      boolean enableGlobalExceptionJsonHandler() default true;
  
      /**
       * RreyRule
       */
      enum GreyRibbonRule{
          /**
           * default grey rule based on  round rule
           */
          DEFAULT,
          /**
           * weight response rule base on WeightResponseRUle
           */
          WeightResponse,
      }
  }

  1.2.0.RELEASE And Latest Version Should use properties settings As Below to Choose which plugin function what you want to use.

  spring:
    profiles:
      active: dev
    cloud:
      gateway:
        plugin:
          config:
            log-request: true
            read-request-data: true
            read-response-data: true
            exception-json-handler: true
          grey:
            enable: false
            grey-ribbon-rule: weight_response

• 4 . User GatewayContext

  You Can Use GatewayContext To Get Cache JsonBody Or Form Body,Just Use

  GatewayContext gatewayContext = exchange.getAttribute(GatewayContext.CACHE_GATEWAY_CONTEXT);

• 5 . The Deference Between GreyRibbonRule.DEFAULT And GreyRibbonRule.WeightResponse

  The Default GreyRibbonRule Just Use Round Rule As Base Ribbon Rule The WeightResponse GreyRibbonRule Use WeightResponse Rule As Base Ribbon Rule

• 6 . The Grey Route

  • Setup Gateway Properties

  1.0.0.RELEASE,1.1.0.RELEASE Grey Rule Setting

  spring:
    cloud:
      gateway:
        grey:
          greyRuleList:
            - serviceId: privider1
              version: 2.0.0
              operation: OR
              rules:
                - key: key1
                  value:
                    - value1
                    - value2
                    - value3
                - key: key2
                  value:
                    - value4
                    - value5
                    - value6
            - serviceId: provider2
              version: 2.0.0
              operation: AND
              rules:
                - key: keya
                  value:
                    - value1a
                    - value2a
                    - value3a
                - key: keyb
                  value:
                    - value4b
                    - value5b
                    - value6b

  1.2.0.RELEASE And Latest Version Grey Rule Setting

  spring:
    cloud:
      gateway:
        plugin:
            grey:
              grey-rule-list:
                - service-id: privider1
                  version: 2.0.0
                  operation: OR
                  rules:
                    - key: key1
                      value:
                        - value1
                        - value2
                        - value3
                    - key: key2
                      value:
                        - value4
                        - value5
                        - value6
                - service-id: provider2
                  version: 2.0.0
                  operation: AND
                  rules:
                    - key: keya
                      value:
                        - value1a
                        - value2a
                        - value3a
                    - key: keyb
                      value:
                        - value4b
                        - value5b
                        - value6b
      

  • Set Up Service MetaInfo

    #proiver1
    eureka:
      instance:
        metadata-map:
          version: 2.0.0 

  • The Properties Active Rule Principle

    When Request URL Route To Provider1,When The Request JsonBody Or Form Data Contain The Key ->Key1 And Match Any Of The Value->[value1,value2,value3] The Route The Request To The Service Which Setup The MetaInfo With Specific Version Which Match The Gateway Grey Setup

• 7 . How To Custom GlobalException Handler With Json

  In Order To Handle Other Exception,You Can Define Specific Bean Implements ExceptionHandlerStrategy By default,plugin supply DefaultExceptionHandlerStrategy In Case Of None Strategy Exist

  @Slf4j
  public class DefaultExceptionHandlerStrategy implements ExceptionHandlerStrategy {
  
      @Override
      public Class getHandleClass() {
          return Throwable.class;
      }
  
      @Override
      public ExceptionHandlerResult handleException(Throwable throwable) {
          ResponseResult<String> responseResult = new ResponseResult<>(SystemResponseInfo.GATEWAY_ERROR,throwable.getMessage());
          ExceptionHandlerResult result = new ExceptionHandlerResult(HttpStatus.INTERNAL_SERVER_ERROR, JSON.toJSONString(responseResult));
          log.debug("[DefaultExceptionHandlerStrategy]Handle Exception:{},Result:{}",throwable.getMessage(),result);
          log.error("[DefaultExceptionHandlerStrategy]Log Exception In Error Level,Exception Message:{}",throwable.getMessage());
          return result;
      }
  }

• 8 . Use Temporary Offline Endpoint

  In some way, Our service need to restart or rebuild .If you use Eureka Discover Server, You know when your service are shutting down, Eureka Server need time to notify all service that.This Endpoint support a rest api to temporary offline some service in 1 minute.

  The Rest Api Is :

  Request Method: Post

  Request URI: /gateway/plugin/offline

  Request ContentType: application/json

  Request Body:

  {
    "name": "serviceId",
    "ip": "serviceIp",
    "port": "servicePort",
    "offlineTime": "serviceOfflineTimestamp"
  }

  Response Data: success Or data-empty-error