【CentOS 7.9】死机卡住如何处理

前言

一、什么是网关

1. 基本概述 

2. 图解

3. 组成结构

4. 应用场景

二、网关的集成使用

1. 新建一个模块作为网关

2.  pom文件设置

<!--    集成主项目-->
    <parent>
        <groupId>com.yx</groupId>
        <artifactId>cloud</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <dependencies>
        <!--    导入网关服务器的依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
<!--        导入网关的依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
    </dependencies>

3. 新建配置文件进行配置

server:
  port: 8082
spring:
  application:
    name: gateway
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
          lower-case-service-id: true

4. 启动类标记使用nacos

5. 使用网关的方式

5.1 方式一：

1. 对其yml文件配置

spring:
  application:
#    名称
    name: gateway
  cloud:
    nacos:
      discovery:
#        地址
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true
          lower-case-service-id: true

 2. 测试演示

 5.2 方式二：

 1. 对其yml文件进行配置

 方式二：
#      设置路由 规则
      routes:
#        -路由标识
        - id: user-provider-api
          #目标服务地址(uri：地址,请求转发后的地址),会自动从注册中心获得服务的IP,不需要手动写死
          uri: lb://provider
          predicates:
            - # 路径匹配,
            - Path=/prov/**
          filters:
            #路径前缀删除示例：请求/name/bar/foo,StripPrefix=2,去除掉前面两个前缀之后,最后转
#            发到目标服务的路径为/foo
            #前缀过滤,请求地址：http://localhost:8084/usr/hello
            #此处配置去掉1个路径前缀,再配置上面的 Path=/usr/**,就将**转发到指定的微服务
            #因为这个api相当于是服务名,只是为了方便以后nginx的代码加上去的,对于服务提供者
#            service-client来说,不需要这段地址,所以需要去掉
            - StripPrefix=1

2. 重启项目测试

5.3 方式三：

1. 编写配置类

 FilterEntity.java

package com.yx.gateway.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.util.LinkedHashMap;
import java.util.Map;

/**
 * @author hgh
 */
@SuppressWarnings("all")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class FilterEntity {

    //过滤器对应的Name
    private String name;

    //路由规则
    private Map<String, String> args = new LinkedHashMap<>();

}

 GatewayNacosProperties.java

package com.yx.gateway.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@SuppressWarnings("all")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
@ConfigurationProperties(prefix = "gateway.nacos")
@Component
public class GatewayNacosProperties {

    private String serverAddr;
    private String dataId;
    private String namespace;
    private String group;

}

PredicateEntity.java

package com.yx.gateway.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.util.LinkedHashMap;
import java.util.Map;

/**
 * @author hgh
 */
@SuppressWarnings("all")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class PredicateEntity {

    //断言对应的Name
    private String name;

    //断言规则
    private Map<String, String> args = new LinkedHashMap<>();

}

 RouteEntity.java

package com.yx.gateway.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.util.ArrayList;
import java.util.List;

/**
 * @author hgh
 */
@SuppressWarnings("all")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class RouteEntity {

    //路由id
    private String id;

    //路由断言集合
    private List<PredicateEntity> predicates = new ArrayList<>();

    //路由过滤器集合
    private List<FilterEntity> filters = new ArrayList<>();

    //路由转发的目标uri
    private String uri;

    //路由执行的顺序
    private int order = 0;

}

DynamicRoutingConfig.java

package com.yx.gateway;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.nacos.api.NacosFactory;
import com.alibaba.nacos.api.PropertyKeyConst;
import com.alibaba.nacos.api.config.ConfigService;
import com.alibaba.nacos.api.config.listener.Listener;
import com.alibaba.nacos.api.exception.NacosException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.yx.gateway.pojo.FilterEntity;
import com.yx.gateway.pojo.GatewayNacosProperties;
import com.yx.gateway.pojo.PredicateEntity;
import com.yx.gateway.pojo.RouteEntity;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
import org.springframework.cloud.gateway.filter.FilterDefinition;
import org.springframework.cloud.gateway.handler.predicate.PredicateDefinition;
import org.springframework.cloud.gateway.route.RouteDefinition;
import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.web.util.UriComponentsBuilder;
import reactor.core.publisher.Mono;

import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.Executor;

/**
 * 此类实现了Spring Cloud Gateway + nacos 的动态路由,
 * 它实现一个Spring提供的事件推送接口ApplicationEventPublisherAware
 */
@SuppressWarnings("all")
@Slf4j
@Component
public class DynamicRoutingConfig implements ApplicationEventPublisherAware {

    @Autowired
    private RouteDefinitionWriter routeDefinitionWriter;

    @Autowired
    private GatewayNacosProperties gatewayProperties;

    @Autowired
    private ObjectMapper mapper;

    private ApplicationEventPublisher applicationEventPublisher;

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        this.applicationEventPublisher = applicationEventPublisher;
    }

    /**
     * 这个方法主要负责监听Nacos的配置变化,这里先使用参数构建一个ConfigService,
     * 再使用ConfigService开启一个监听,
     * 并且在监听的方法中刷新路由信息。
     */
    @Bean
    public void refreshRouting() throws NacosException {
        //创建Properties配置类
        Properties properties = new Properties();
        System.out.println(gatewayProperties);
        //设置nacos的服务器地址,从配置类GatewayProperties中获取
        properties.put(PropertyKeyConst.SERVER_ADDR, gatewayProperties.getServerAddr());
        //设置nacos的命名空间,表示从具体的命名空间中获取配置信息,不填代表默认从public获得
        if (gatewayProperties.getNamespace() != null) {
            properties.put(PropertyKeyConst.NAMESPACE, gatewayProperties.getNamespace());
        }
        //根据Properties配置创建ConfigService类
        ConfigService configService = NacosFactory.createConfigService(properties);
        //获得nacos中已有的路由配置
        String json = configService.getConfig(gatewayProperties.getDataId(), gatewayProperties.getGroup(), 5000);
        this.parseJson(json);

        //添加监听器,监听nacos中的数据修改事件
        configService.addListener(gatewayProperties.getDataId(), gatewayProperties.getGroup(), new Listener() {
            @Override
            public Executor getExecutor() {
                return null;
            }

            /**
             * 用于接收远端nacos中数据修改后的回调方法
             */
            @Override
            public void receiveConfigInfo(String configInfo) {
                log.warn(configInfo);
                //获取nacos中修改的数据并进行转换
                parseJson(configInfo);
            }
        });

    }

    /**
     * 解析从nacos读取的路由配置信息(json格式)
     */
    public void parseJson(String json) {
        log.warn("从Nacos返回的路由配置(JSON格式)：" + json);
        boolean refreshGatewayRoute = JSONObject.parseObject(json).getBoolean("refreshGatewayRoute");
        if (refreshGatewayRoute) {
            List<RouteEntity> list = JSON.parseArray(JSONObject.parseObject(json).getString("routeList")).toJavaList(RouteEntity.class);
            for (RouteEntity route : list) {
                update(assembleRouteDefinition(route));
            }
        } else {
            log.warn("路由未发生变更");
        }
    }


    /**
     * 路由更新
     */
    public void update(RouteDefinition routeDefinition) {

        try {
            this.routeDefinitionWriter.delete(Mono.just(routeDefinition.getId()));
            log.warn("路由删除成功:" + routeDefinition.getId());
        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }
        try {
            routeDefinitionWriter.save(Mono.just(routeDefinition)).subscribe();
            this.applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this));
            log.warn("路由更新成功:" + routeDefinition.getId());
        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }

    }

    /**
     * 路由定义
     */
    public RouteDefinition assembleRouteDefinition(RouteEntity routeEntity) {

        RouteDefinition definition = new RouteDefinition();

        // ID
        definition.setId(routeEntity.getId());

        // Predicates
        List<PredicateDefinition> pdList = new ArrayList<>();
        for (PredicateEntity predicateEntity : routeEntity.getPredicates()) {
            PredicateDefinition predicateDefinition = new PredicateDefinition();
            predicateDefinition.setArgs(predicateEntity.getArgs());
            predicateDefinition.setName(predicateEntity.getName());
            pdList.add(predicateDefinition);
        }
        definition.setPredicates(pdList);

        // Filters
        List<FilterDefinition> fdList = new ArrayList<>();
        for (FilterEntity filterEntity : routeEntity.getFilters()) {
            FilterDefinition filterDefinition = new FilterDefinition();
            filterDefinition.setArgs(filterEntity.getArgs());
            filterDefinition.setName(filterEntity.getName());
            fdList.add(filterDefinition);
        }
        definition.setFilters(fdList);

        // URI
        URI uri = UriComponentsBuilder.fromUriString(routeEntity.getUri()).build().toUri();
        definition.setUri(uri);

        return definition;
    }

}

 2. 导入所需依赖

<!--           导入阿里的fastjson的依赖-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.35</version>
        </dependency>

 3. 在nacos中创建一个json文件

json内容

{
  "refreshGatewayRoute": true,
  "routeList": [
    {
      "id": "consumer-api",
      "predicates": [
        {
          "name": "Path",
          "args": {
            "_genkey_0": "/cum/**"
          }
        }
      ],
      "filters": [
        {
          "name": "StripPrefix",
          "args": {
            "_genkey_0": "1"
          }
        }
      ],
      "uri": "lb://consumer",
      "order": 0
    },
    {
      "id": "provider-api",
      "predicates": [
        {
          "name": "Path",
          "args": {
            "_genkey_0": "/pvr/**"
          }
        }
      ],
      "filters": [
        {
          "name": "StripPrefix",
          "args": {
            "_genkey_0": "1"
          }
        }
      ],
      "uri": "lb://provider",
      "order": 0
    }
  ]
}

4. 测试效果