Zuul网关

柔情只为你懂 2022-01-21 07:11 370阅读 0赞

## 引入依赖 ##

<dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
            </dependency>

1.启动类中注解 @EnableZuulProxy  
2.配置转发规则  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Zpdmlicm8_size_16_color_FFFFFF_t_70]

##### 默认去除前缀，访问的路径会从path后直接拼接 #####

##### 但是有个问题，服务路径写死了，没有引入负载均衡等 #####

##### 所以不推荐路由规则中写URL 应该写入service ID #####

# 引入eureka： #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Zpdmlicm8_size_16_color_FFFFFF_t_70 1]  
这样访问可以由注册中心来调度服务

可以简化route为 “服务名:拦截规则”的形式

zuul:
    	routes:
    	user-service: /user-service/**

在使用Zuul的过程中，上面讲述的规则已经大大的简化了配置项。但是当服务较多时，配置也是比较繁琐的。因此Zuul就指定了默认的路由规则：

*  默认情况下，一切服务的映射路径就是服务名本身。
    
     *  例如服务名为：user-service，则默认的映射路径就是：/user-service/\*\*

### 也就是说，刚才的映射规则我们完全不配置也是OK. ###

### 另外routes里面有一个prefix属性 指定路由前缀 ###

eg：

zuul:
    	prefix: /api       #路径/api/user-service/user/1将会被代理到/user-service/user/1

### 不想对外暴露的服务，可以设置一个set ###

zuul:
    	ignored-services: 
    	- customer-serviece
    	- hello-service

### 去除前缀 ###

默认是去除后拼接路径，  
**strip-prefix**属性可以设置为false将原访问path直接接到url或者转发服务上，该属性可以全局配置

# 过滤器 #

ZuulFilter是父类，内含4个主要方法

String filterType();//过滤器类型
    int filterOrder();//过滤器优先级
    boolean shouldFilter();//是否过滤
    object run() throws ZuulException;//过滤逻辑

**filterType**分为4种 pre前置、post后置、error异常、routing路由时执行  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Zpdmlicm8_size_16_color_FFFFFF_t_70 2]  
pre用到的最多，多用于身份校验、限流等

**拿到request的方法可以参照ZuulFilter的其他前置拦截实现类**

RequestContext ctx = RequestContext.getCurrentContext();
    HttpServletRequest req = ctx.getRequest(); // 2) 从上下文中获取request对象
    String token = req.getParameter("access-token");// 3) 从请求中获取token

拿到token再进行判断

自定义过滤器判断access-token登录filter的Demo代码：

package cn.vivi.filter;
    
    import com.netflix.zuul.ZuulFilter;
    import com.netflix.zuul.context.RequestContext;
    import com.netflix.zuul.exception.ZuulException;
    import org.apache.commons.lang3.StringUtils;
    import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
    import org.springframework.cloud.netflix.zuul.filters.support.FilterConstants;
    import org.springframework.http.HttpStatus;
    import org.springframework.stereotype.Component;
    
    import javax.servlet.http.HttpServletRequest;
    
    @Component
    public class LoginFilter extends ZuulFilter {
        @Override
        public String filterType() {
            return FilterConstants.PRE_TYPE;
        }
    
        @Override
        public int filterOrder() {
            return FilterConstants.PRE_DECORATION_FILTER_ORDER - 1;
        }
    
        @Override
        public boolean shouldFilter() {
            return true;
        }
    
        @Override
        public Object run() throws ZuulException {
            RequestContext currentContext = RequestContext.getCurrentContext();
            HttpServletRequest request = currentContext.getRequest();
            String token = request.getParameter("access-token");
            if(StringUtils.isBlank(token)){
    //            未登录则拦截 默认为ture放行
                currentContext.setSendZuulResponse(false);
    //            返回403
                currentContext.setResponseStatusCode(HttpStatus.FORBIDDEN.value());
            }
            return null;
        }
    }

**StringUtils**源自于

<dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
            </dependency>

可以用于快速判null及空

另外需要设置白名单，在shouldFilter判断是否进行拦截检查，不是所有页面都需要身份验证。

## Zuul集成的负载均衡及熔断 ##

zuul:
      retryable: true
    ribbon:
      ConnectTimeout: 250 # 连接超时时间(ms)
      ReadTimeout: 2000 # 通信超时时间(ms)
      OkToRetryOnAllOperations: true # 是否对所有操作重试
      MaxAutoRetriesNextServer: 2 # 同一服务不同实例的重试次数
      MaxAutoRetries: 1 # 同一实例的重试次数
    hystrix:
      command:
        default:
          execution:
            isolation:
              thread:
                timeoutInMilliseconds: 6000 #超时时长

ribbon的超时时长=(ConnectTimeout+ReadTimeout) \* (MaxAutoRetriesNextServer+1)\* ( MaxAutoRetries+1)  
默认(ConnectTimeout+ReadTimeout)\*2  
hystrix的熔断时长应大于ribbon的timeout。

**zuul对各个服务实现了负载均衡，但是为了保证zuul的高可用，必须将Zuul做成集群，但是用户不能直接调用集群，所以在zuul之上还需要nginx来做zuul的负载均衡，nginx可以利用ip漂移**

以下报错信息是由于  
版本升级到Dalston.SR4之后feign使用hystrix时启动报如上错误  
解决办法：引入hystrix依赖包，不然找不到hystrix-contrib包

java.lang.IllegalStateException: Error processing condition on org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration.propertySourcesPlaceholderConfigurer
    	at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:64) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:108) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(ConfigurationClassBeanDefinitionReader.java:180) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:141) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:117) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:328) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:233) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:271) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:91) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:694) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:762) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:398) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:330) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1258) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at com.vivi.DgItemApplication.main(DgItemApplication.java:10) [classes/:na]
    Caused by: java.lang.IllegalStateException: Failed to introspect Class [org.springframework.cloud.netflix.hystrix.HystrixCircuitBreakerConfiguration] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
    	at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:659) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:556) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:541) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:599) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:718) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:659) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:627) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1489) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1012) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.BeanTypeRegistry.addBeanTypeForNonAliasDefinition(BeanTypeRegistry.java:180) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.BeanTypeRegistry.addBeanTypeForNonAliasDefinition(BeanTypeRegistry.java:160) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.BeanTypeRegistry.addBeanType(BeanTypeRegistry.java:153) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.BeanTypeRegistry.updateTypesIfNecessary(BeanTypeRegistry.java:215) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.BeanTypeRegistry.getNamesForType(BeanTypeRegistry.java:115) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.OnBeanCondition.collectBeanNamesForType(OnBeanCondition.java:265) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getBeanNamesForType(OnBeanCondition.java:254) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getMatchingBeans(OnBeanCondition.java:196) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getMatchOutcome(OnBeanCondition.java:116) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:47) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	... 17 common frames omitted
    Caused by: java.lang.NoClassDefFoundError: com/netflix/hystrix/contrib/javanica/aop/aspectj/HystrixCommandAspect
    	at java.lang.Class.getDeclaredMethods0(Native Method) ~[na:1.8.0_131]
    	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) ~[na:1.8.0_131]
    	at java.lang.Class.getDeclaredMethods(Class.java:1975) ~[na:1.8.0_131]
    	at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:641) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	... 35 common frames omitted
    Caused by: java.lang.ClassNotFoundException: com.netflix.hystrix.contrib.javanica.aop.aspectj.HystrixCommandAspect
    	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_131]
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_131]
    	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335) ~[na:1.8.0_131]
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_131]
    	... 39 common frames omitted
    
    2019-07-03 11:08:05.485  INFO 9268 --- [           main] ConfigServletWebServerApplicationContext : Closing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@3561c410: startup date [Wed Jul 03 11:08:05 CST 2019]; parent: org.springframework.context.annotation.AnnotationConfigApplicationContext@1189dd52
    2019-07-03 11:08:05.486  WARN 9268 --- [           main] o.s.boot.SpringApplication               : Unable to close ApplicationContext
    
    java.lang.IllegalStateException: Failed to introspect Class [org.springframework.cloud.netflix.hystrix.HystrixCircuitBreakerConfiguration] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
    	at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:659) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:556) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:541) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:599) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:718) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:659) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:627) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1489) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:419) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:389) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:510) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:502) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1198) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:892) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:878) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:864) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:813) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:341) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1258) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    	at com.vivi.DgItemApplication.main(DgItemApplication.java:10) [classes/:na]
    Caused by: java.lang.NoClassDefFoundError: com/netflix/hystrix/contrib/javanica/aop/aspectj/HystrixCommandAspect
    	at java.lang.Class.getDeclaredMethods0(Native Method) ~[na:1.8.0_131]
    	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) ~[na:1.8.0_131]
    	at java.lang.Class.getDeclaredMethods(Class.java:1975) ~[na:1.8.0_131]
    	at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:641) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    	... 20 common frames omitted
    Caused by: java.lang.ClassNotFoundException: com.netflix.hystrix.contrib.javanica.aop.aspectj.HystrixCommandAspect
    	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_131]
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_131]
    	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335) ~[na:1.8.0_131]
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_131]
    	... 24 common frames omitted

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-hystrix</artifactId>
    </dependency>

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Zpdmlicm8_size_16_color_FFFFFF_t_70]: /images/20220121/07e4f1b6c8f440dfbb68b5a5b3633308.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Zpdmlicm8_size_16_color_FFFFFF_t_70 1]: /images/20220121/8c48d7148a8a4955bb487a6e20a1cc2b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Zpdmlicm8_size_16_color_FFFFFF_t_70 2]: /images/20220121/ad4fff9528124e469846002142e2c4f0.png