Dynamically add default fusing rules to feign client based on sentinel + Nacos

As the business grows , Micro service is imperative ; Recently took over an old project to use sentinel+nacos Fusing and current limiting , The fuse rules are configured the same , I feel a little redundant , Inefficient development . Think about upgrading , Because the service depends on the interface, it is through feignClient Called , Yes feignClient Call interface , Automatic scanning and dynamic realization of fuse rules .

One 、 Home page scanning feignClient Dependent interface , Dynamically generate fusing rules , push nacos

1. Realization ApplicationRunner Interface , rewrite run Method , according to EnableFeignClients Specify the package to load feignClient Class collection

      @Override
      public void run(ApplicationArguments args) {
         
          Class<?> mainClass = deduceMainApplicationClass();
          log.info(" Start loading default rules ,mainClass:{}", mainClass);
          if (mainClass == null) {
         
              throw new RuntimeException("can not fount main class");
          }
          EnableFeignClients enableFeignClientsAnnotation = mainClass.getAnnotation(EnableFeignClients.class);
          if (enableFeignClientsAnnotation != null) {
         
              String[] feignClientPackages;
              String[] feignClientDeclaredPackages = enableFeignClientsAnnotation.basePackages();
              // The statement feignClient The package name 
              if (feignClientDeclaredPackages.length == 0) {
         
                  feignClientPackages = new String[]{
         mainClass.getPackage().getName()};
              } else {
         
                  feignClientPackages = feignClientDeclaredPackages;
              }
              // Initialize demotion rule 
              initDeGradeRule(feignClientPackages);
          }
          log.info(" The default degradation rule processing is completed ");
      }
   

2. according to feignClient Class collection , Initialize the fusing rule , And push nacos

       private void initDeGradeRule(String[] feignClientPackages) {
         
           List<DegradeRule> localDegradeRuleList = new ArrayList<>();
           Set<Class> feignClientClass = getFeignClientClass(feignClientPackages);
           for (Class clientClass : feignClientClass) {
         
               List<DegradeRule> rules = initRules(clientClass);
               localDegradeRuleList.addAll(rules);
           }
           List<DegradeRule> remoteDegradeRuleList = fetchRemoteRules();
           // long-range nacos There are no rules , Then use local rules directly 
           if (remoteDegradeRuleList == null || remoteDegradeRuleList.isEmpty()) {
         
               pushRules(localDegradeRuleList);
               return;
           }
           // Local rules   Merge   Remote rule policy 
           proess(localDegradeRuleList, remoteDegradeRuleList);
           // Push local rules , To nacos
           pushRules(localDegradeRuleList);
       }
   

3. obtain FeignClient class set

       private Set<Class> getFeignClientClass(String[] packageNames) {
         
           ClassScanner classScanner = new ClassScanner();
           Set<Class> feignClientClass = new HashSet<>();
           for (String packageName : packageNames) {
         
               feignClientClass.addAll(classScanner.scan(packageName, FeignClient.class));
           }
           return feignClientClass;
       }
   

4. according to feignClient class object , Extract request mapping

       private final static String HTTP_PROTOCOL_PREFIX = "http://";
       private final static String ANNOTATION_VALUE_PREFIX = "${";
       private final static String ANNOTATION_VALUE_SUFFIX = "}";    
   public List<DegradeRule> initRules(Class cla) {
         
           List<DegradeRule> degradeRuleList = new ArrayList<>();
           FeignClient feignClient = (FeignClient) cla.getAnnotation(FeignClient.class);
           String classRequestMappingUrl = "";
           RequestMapping classRequestMapping = (RequestMapping) cla.getAnnotation(RequestMapping.class);
           if (null != classRequestMapping) {
         
               classRequestMappingUrl = classRequestMapping.value()[0];
           }
           String serviceName = feignClient.name();
           if (serviceName.startsWith(ANNOTATION_VALUE_PREFIX) && serviceName.endsWith(ANNOTATION_VALUE_SUFFIX)) {
         
               serviceName = this.environment.resolvePlaceholders(serviceName);
           }
           Method[] methods = cla.getDeclaredMethods();
           for (Method method : methods) {
         
               degradeRuleList.add(buildDegradeRule(getResourceName(classRequestMappingUrl, serviceName, method)));
           }
           DegradeRuleManager.loadRules(degradeRuleList);
           return degradeRuleList;
   

5. Map on request , Splice resource identification

       private String getResourceName(String crmu, String serviceName, Method method) {
           crmu = crmu.startsWith("/") ? crmu : "/" + crmu;
           String resourceName = "";
           RequestMapping methodRequestMapping = method.getAnnotation(RequestMapping.class);
           if (null != methodRequestMapping) {
               String mrm = methodRequestMapping.value()[0];
               resourceName = HTTP_PROTOCOL_PREFIX + serviceName + crmu + (mrm.startsWith("/") ? mrm : "/" + mrm);
           }
           PostMapping methodPostMapping = method.getAnnotation(PostMapping.class);
           if (null != methodPostMapping) {
               String mpm = methodPostMapping.value()[0];
               resourceName = HTTP_PROTOCOL_PREFIX + serviceName + crmu + (mpm.startsWith("/") ? mpm : "/" + mpm);
           }
           return resourceName;
       }
   

6. Use resource identification , Build default rules

       private DegradeRule buildDegradeRule(String resourceName) {
         
           DegradeRule rule = new DegradeRule();
           // Set resource name 
           rule.setResource(resourceName);
           // Set degradation rules  TR 10 ms
           rule.setCount(200);
           //  Type of rule  RT
           rule.setGrade(RuleConstant.DEGRADE_GRADE_RT);
           //  Window time 
           rule.setTimeWindow(10);
           rule.setMinRequestAmount(3);
           rule.setStatIntervalMs(30000);
           rule.setSlowRatioThreshold(0.6);
           return rule;
       }
   

7. Get remote nacos To configure

       private List<DegradeRule> fetchRemoteRules() {
           return JSONObject.parseArray(nacosService.getConfig(dataId, groupId), DegradeRule.class);
       }
   

8. Local rules Merge Remote rule policy

       private void proess(List<DegradeRule> localDegradeRuleList, List<DegradeRule> remoteDegradeRuleList) {
         
           for (DegradeRule rule : remoteDegradeRuleList) {
         
               if (localDegradeRuleList.contains(rule)) {
         
                   DegradeRule ldr = localDegradeRuleList.get(localDegradeRuleList.indexOf(rule));
                   if (ldr.equals(rule)) {
         
                       continue;
                   }
                   localDegradeRuleList.remove(ldr);
                   localDegradeRuleList.add(rule);
               } else {
         
                   localDegradeRuleList.add(rule);
               }
           }
       }
   
   

9. Push the fusing rule to nacos

       private void pushRules(List<DegradeRule> localDegradeRuleList) {
           SerializeConfig serializeConfig = new SerializeConfig();
           serializeConfig.propertyNamingStrategy = PropertyNamingStrategy.CamelCase;
           String contentStr = JSON.toJSONString(localDegradeRuleList, serializeConfig, SerializerFeature.PrettyFormat);
           nacosService.publish(dataId, groupId, contentStr, ConfigType.JSON.getType());
       }
   

Two 、 Use AOP cut feign call , Dynamically add fuse logic execution

10. Reference resources Sentinel Of SentinelResourceAspect Inherit AbstractSentinelAspectSupport Realization feign Call interception

@Aspect
@Slf4j
@Component
public class FeignMethodAspect extends AbstractSentinelAspectSupport {
    

    @Around("within(feign.Client+)")
    public Object around(ProceedingJoinPoint pjp) throws Throwable {
    
        log.info("within(feign.Client+) pjp {}, args:{}", pjp, pjp.getArgs());
        String resourceName = pjp.getArgs()[0].toString().split(" ")[1];
        Entry entry = null;
        try {
    
            Object var18;
            try {
    
                entry = SphU.entry(resourceName, ResourceTypeConstants.COMMON, EntryType.OUT, pjp.getArgs());
                Object result = pjp.proceed();
                var18 = result;
                return var18;
            } catch (BlockException var15) {
    
                String resource = var15.getRule().getResource();
                log.error("FeignClient Interface triggers resource:{} The rules , The interface has been “ Current limiting / Fuse / Downgrade ”, The business system returns the default null value , Abnormal information ：{}", resource, var15);
                return null;
            } catch (Throwable var16) {
    
                this.traceException(var16);
            }
        } finally {
    
            if (entry != null) {
    
                entry.exit(1, pjp.getArgs());
            }
        }
        return null;
    }
}

11. Configuration and use JDK A dynamic proxy , Otherwise intercept feignClient The call fails

spring:
  aop:
    proxy-target-class: false

12. push nacosService rely on NacosConfigManager

    public Boolean publish(String dataId, String group, String content, String type) {
    
        try {
    
            return nacosConfigManager.getConfigService().publishConfig(dataId, group, content, type);
        } catch (NacosException e) {
    
            log.error("NacosService publish e:{}", e);
        }
        return false;
    }

13. obtain nacos To configure

    public String getConfig(String dataId, String group) {
    
        try {
    
            return nacosConfigManager.getConfigService().getConfig(dataId, group, 10000l);
        } catch (NacosException e) {
    
            log.error("NacosService publish e:{}", e);
        }
        return Strings.EMPTY;
    }

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