Spring Cloud

2.1 配置文件命名格式

2.2 Config Server

<project>
  <dependencies>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-config-server</artifactId>
    </dependency>
  </dependencies>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Greenwich.SR2</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>
</project>

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.config.server.EnableConfigServer;

@SpringBootApplication
@EnableConfigServer
public class Application {

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

}

spring:
  profiles:
    active: default
  cloud:
    config:
      server:
        git:
          uri: http://github.com/avic/configfiles.git
          searchPaths:
            - path1
            - path2
          username: user
          password: pass

2.3 Config Client

<!-- pom.xml -->
<project>
  <!-- 1. 添加下面四个依赖项 -->
  <dependencies>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-config</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <!-- 2. 设置依赖管理 -->
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <!-- 这个 version 需要和你使用的 spring boot 版本适配，否则应用起不来 -->
        <version>Greenwich.SR2</version>
        <!-- 我的项目中 spring boot 版本是 2.1.0.RELEASE, 所以 cloud 的版本使用 Greenwich -->
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

</project>

# src/main/resources/application.yml
management:
  endpoints:
    web:
      exposure:
        include: '*'

# src/main/resources/bootstrap.yml
spring:
  application:
    name: appname # 这里写你项目的名称
  profiles:
    active: dev   # 这里配置你需要的 profile
  cloud:
    config:
      uri: http://192.168.0.231/peizhi

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.context.config.annotation.RefreshScope;

@SpringBootApplication
@RefreshScope
public class Application {
  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}

3.1 Eureka

3.2 Hystrix

3.3 Zuul

1. 配置相关文件
   

   pom.xml 添加 spring-cloud-starter-netflix-zuul 的依赖项将 Zuul 引入项目

   <!-- pom.xml -->
   <project>
     <dependencies>
       <dependency>
         <groupId>org.springframework.cloud</groupId>
         <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
       </dependency>
     </dependencies>
   </project>
   

2. 配置引导类
   

   @SpringBootApplication
   @EnableZuulProxy
   public class Application {
   
     public static void main(String[] args) {
       new SpringApplicationBuilder(Application.class).web(true).run(args);
     }
   
   }
   

   @EnableZuulProxy 来开启 Zuul 服务

3. 配置反向代理
   

   Zuul 的反向代理使用的是以下几种方式进行设置

   • 通过服务发现自动映射路由
   • 通过服务发现手动映射路由
   • 通过静态 URL 手动映射路由

   使用 @EnableZuulProxy 开启 Zuul 服务后，如果正确地配置了 Eureka Client 服务的话，不需要进行其它的配置就可以自动映射路由。根据惯例，Zuul 会自动给 反向代理的微服务添加前缀，例如： 如果微服务的名字是 users ，则 Zuul 会将 /users/** 的请求全部映射到 users 微服务中

   手动配置反向代理需要修改 application.yml 配置文件，例如下面的配置将 /myusers/** 请求传递到 users 微服务中

   zuul:
    routes:
      users:
        path: /myusers/**
        serviceId: users_service
   

   使用静态 URL 手动映射路由

   zuul:
    routes:
      users:
        path: /myusers/**
        url: https://example.com/users_service
   

4. 忽略某些微服务
   

   Zuul 允许配置对一些微服务的忽略项

   # 忽略所有微服务
   zuul:
     ignoredServices: '*'
     routes:
       users: /myusers/**
   
   # 忽略某个微服务，微服务的名字为 appname
   zuul:
     ignoredServices: 'appname'
     routes:
       users: /myusers/**
   
   # 添加统一的前缀 /api
   zuul:
     ignoredServices: '*'
     prefix: /api
     routes:
       users: /myusers/**
   
   # 忽略所有带有 /admin/ 路由的调用接口
   zuul:
     ignoredPatterns: /**/admin/**
     routes:
       users: /myusers/**
   

5. 头部的设置选项
   

   将 Cookies, Set-Cookie, Authorization 设置成敏感的头部，忽略一些头部

   zuul:
     routes:
       users:
         path: /myusers/**
         # Cookies 和敏感的头部
         sensitiveHeaders: Cookie,Set-Cookie,Authorization
         # 忽略的头部
         ignoredHeaders: Header1
         # 是否忽略安全头部
         ignoreSecurityHeaders: true
         url: https://downstream
   

6. 管理端点 Endpoint
   

   Zuul 提供了一些管理路由的 RESTful 接口

   • GET /routes 获取所有解析的路由
   • GET /routes/detail 获取详细路由信息
   • POST /routes 强制刷新路由
   • GET /filter 获取所有的过滤器

   下面是一些示例

   curl http://localhost/routes
   

   {
     "/stores/**": "http://localhost:8081"
   }
   

   curl http://localhost/routes/detail
   

   {
     "/stores/**": {
       "id": "stores",
       "fullPath": "/stores/**",
       "location": "http://localhost:8081",
       "path": "/**",
       "prefix": "/stores",
       "retryable": false,
       "customSensitiveHeaders": false,
       "prefixStripped": true
     }
   }
   

7. 基本使用场景
   

   如下所示将相关路由反向代理到对应的 URL

   原始请求	代理后的请求
   /fisrt/1	https://first.exmple.com/1
   /second/2	/second/2
   /third/3	/3rd/3
   /no	https://legacy.example.com/no

   zuul:
    routes:
      first:
        path: /first/**
        url: https://first.example.com
      second:
        path: /second/**
        url: forward:/second
      third:
        path: /third/**
        url: forward:/3rd
      legacy:
        path: /**
        url: https://legacy.example.com
   

   Zuul 的详细配置见 Zuul wiki

8. 过滤器
   

   前置过滤器（Pre Filter）的在请求之前先进行处理，设置 RequestContext 的相 关参数提供后面的处理

   public class QueryParamPreFilter extends ZuulFilter {
     @Override
     public int filterOrder() {
       return PRE_DECORATION_FILTER_ORDER - 1; // run before PreDecoration
     }
   
     @Override
     public String filterType() {
       return PRE_TYPE;
     }
   
     @Override
     public boolean shouldFilter() {
       RequestContext ctx = RequestContext.getCurrentContext();
       return !ctx.containsKey(FORWARD_TO_KEY) // a filter has already forwarded
         && !ctx.containsKey(SERVICE_ID_KEY); // a filter has already determined serviceId
     }
   
     @Override
     public Object run() {
       RequestContext ctx = RequestContext.getCurrentContext();
       HttpServletRequest request = ctx.getRequest();
       if (request.getParameter("sample") != null) {
         // put the serviceId in `RequestContext`
         ctx.put(SERVICE_ID_KEY, request.getParameter("foo"));
       }
       return null;
     }
   }
   

   路由过滤器（Route Filter）在前置过滤器之后，请求其它服务之前。通常路由过滤 器用来转义请求和回复的数据，下面是一个例子

   public class OkHttpRoutingFilter extends ZuulFilter {
     @Autowired
     private ProxyRequestHelper helper;
   
     @Override
     public String filterType() {
       return ROUTE_TYPE;
     }
   
     @Override
     public int filterOrder() {
       return SIMPLE_HOST_ROUTING_FILTER_ORDER - 1;
     }
   
     @Override
     public boolean shouldFilter() {
       return RequestContext.getCurrentContext().getRouteHost() != null
         && RequestContext.getCurrentContext().sendZuulResponse();
     }
   
     @Override
     public Object run() {
       OkHttpClient httpClient = new OkHttpClient.Builder()
         // customize
         .build();
   
       RequestContext context = RequestContext.getCurrentContext();
       HttpServletRequest request = context.getRequest();
   
       String method = request.getMethod();
   
       String uri = this.helper.buildZuulRequestURI(request);
   
       Headers.Builder headers = new Headers.Builder();
       Enumeration<String> headerNames = request.getHeaderNames();
       while (headerNames.hasMoreElements()) {
         String name = headerNames.nextElement();
         Enumeration<String> values = request.getHeaders(name);
   
         while (values.hasMoreElements()) {
           String value = values.nextElement();
           headers.add(name, value);
         }
       }
   
       InputStream inputStream = request.getInputStream();
   
       RequestBody requestBody = null;
       if (inputStream != null && HttpMethod.permitsRequestBody(method)) {
         MediaType mediaType = null;
         if (headers.get("Content-Type") != null) {
           mediaType = MediaType.parse(headers.get("Content-Type"));
         }
         requestBody = RequestBody.create(mediaType, StreamUtils.copyToByteArray(inputStream));
       }
   
       Request.Builder builder = new Request.Builder()
         .headers(headers.build())
         .url(uri)
         .method(method, requestBody);
   
       Response response = httpClient.newCall(builder.build()).execute();
   
       LinkedMultiValueMap<String, String> responseHeaders = new LinkedMultiValueMap<>();
   
       for (Map.Entry<String, List<String>> entry : response.headers().toMultimap().entrySet()) {
         responseHeaders.put(entry.getKey(), entry.getValue());
       }
   
       this.helper.setResponse(response.code(), response.body().byteStream(), responseHeaders);
       context.setRouteHost(null); // prevent SimpleHostRoutingFilter from running
       return null;
     }
   }
   

   后置路由器（Post Filter）主要处理回复，下面是一个添加 UUID 和 X-Sample 头的例子

   public class AddResponseHeaderFilter extends ZuulFilter {
     @Override
     public String filterType() {
       return POST_TYPE;
     }
   
     @Override
     public int filterOrder() {
       return SEND_RESPONSE_FILTER_ORDER - 1;
     }
   
     @Override
     public boolean shouldFilter() {
       return true;
     }
   
     @Override
     public Object run() {
       RequestContext context = RequestContext.getCurrentContext();
       HttpServletResponse servletResponse = context.getResponse();
       servletResponse.addHeader("X-Sample", UUID.randomUUID().toString());
       return null;
     }
   }
   

3.4 Ribbon