本文是《spring-cloud-kubernetes实战系列》的第五篇,主要内容是在kubernetes上部署一个SpringCloud Gateway应用,该应用使用了spring-cloud-kubernetes框架,可以将请求转发到kubernetes环境中的其他服务上;

系列文章列表

  1. 《spring-cloud-kubernetes官方demo运行实战》
  2. 《你好spring-cloud-kubernetes》
  3. 《spring-cloud-kubernetes背后的三个关键知识点》
  4. 《spring-cloud-kubernetes的服务发现和轮询实战(含熔断)》
  5. 《spring-cloud-kubernetes与SpringCloud Gateway》
  6. 《spring-cloud-kubernetes与k8s的configmap》

本文大纲

接下来的内容由以下几部分组成:

  1. 什么是SpringCloud Gateway
  2. SpringCloud Gateway实战参考
  3. kubernetes上的SpringCloud Gateway
  4. 实战环境信息
  5. 实战源码下载
  6. 开发webdemo
  7. 开发k8sgatewaydemo
  8. 解决权限问题
  9. 最后一个疑问

什么是SpringCloud Gateway

SpringCloud Gateway是SpringCloud技术栈下的网关服务框架,在基于SpringCloud的微服务环境中,外部请求会到达SpringCloud Gateway应用,该应用对请求做转发、过滤、鉴权、熔断等前置操作,一个典型的请求响应流程如下所示:

SpringCloud Gateway实战参考

如果您之前没有使用过SpringCloud Gateway,推荐您阅读《速体验SpringCloud Gateway》,有时间的话动手实战效果更佳,只需编写少量代码就能快速熟悉这个SpringCloud技术栈中非常重要的功能;

kubernetes上的SpringCloud Gateway

注意以下两个知识点:

  1. SpringCloud Gateway之所以能将外部请求路由到正确的后台服务上,是因为注册中心的存在,SpringCloud Gateway可以在注册中心取得所有服务的信息,因此它可以根据路径和服务的对应关系,将请求转发到对应的服务上;
  2. 如果您看过本系列的上一篇 《spring-cloud-kubernetes的服务发现和轮询实战(含熔断)》,您就知道spring-cloud-kubernetes框架可以获取kubernetes环境内的所有服务(这里说的服务就是kubernetes的service);

将以上两个知识点结合起来,于是可以推测:运行在kubernetes环境的SpringCloud Gateway应用,如果使用了spring-cloud-kubernetes框架就能得到kubernetes的service列表,因此可以承担网关的角色,将外部请求转发至kubernetes内的service上,最终到达对应的Pod;

架构如下图所示,请注意黄色背景的对话框,里面标识了关键操作:



至此,理论分析已经完成,我们来实战验证这个理论,接下来我们开发两个java应用:

  1. 先开发一个普通的web服务,名为webdemo,提供一个http接口;
  2. 再开发一个SpringCloud Gateway应用,名为k8sgatewaydemo;

环境信息

本次实战的环境和版本信息如下:

  1. 操作系统:CentOS Linux release 7.6.1810
  2. minikube:1.1.1
  3. Java:1.8.0_191
  4. Maven:3.6.0
  5. fabric8-maven-plugin插件:3.5.37
  6. spring-cloud-kubernetes:1.0.1.RELEASE
  7. spring cloud:Greenwich.SR2
  8. springboot:2.1.6.RELEASE

源码下载

如果您不打算写代码,也可以从GitHub上下载本次实战的源码,地址和链接信息如下表所示:

名称 链接 备注
项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页
git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址,https协议
git仓库地址(ssh) git@github.com:zq2599/blog_demos.git 该项目源码的仓库地址,ssh协议


这个git项目中有多个文件夹,本章的两个应用分别在webdemo和k8sgatewaydemo文件夹下;

下图红框中是webdemo应用的源码:



下图红框中是k8sgatewaydemo应用的源码:



下面是详细的编码过程;

开发webdemo

webdemo是个极其普通的spring boot应用,和SpringCloud没有任何关系;

  1. webdemo提供一个http接口,将请求header中名为extendtag的参数返回给请求方,controller类如下:
@RestController
@RequestMapping("/hello")
public class HelloController { @RequestMapping(value = "time", method = RequestMethod.GET)
public String hello(HttpServletRequest request){ return "hello, "
+ new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date())
+ ", extendtag ["
+ request.getHeader("extendtag")
+ "]";
}
}
  1. 启动类WebdemoApplication.java:
@SpringBootApplication
public class WebdemoApplication {
public static void main(String[] args) {
SpringApplication.run(WebdemoApplication.class, args);
}
}
  1. 要注意的是pom.xml,里面通过名为fabric8-maven-plugin的maven插件,将webdemo快速部署到minikube环境:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.bolingcavalry</groupId>
<artifactId>webdemo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>webdemo</name>
<description>Demo project for Spring Boot</description> <properties>
<java.version>1.8</java.version>
<spring-boot.version>2.1.6.RELEASE</spring-boot.version>
<fabric8.maven.plugin.version>3.5.37</fabric8.maven.plugin.version>
</properties> <dependencies>
<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> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>${spring-boot.version}</version>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin> <plugin>
<!--skip deploy -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-deploy-plugin</artifactId>
<version>${maven-deploy-plugin.version}</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${maven-surefire-plugin.version}</version>
<configuration>
<skipTests>true</skipTests>
<!-- Workaround for https://issues.apache.org/jira/browse/SUREFIRE-1588 -->
<useSystemClassLoader>false</useSystemClassLoader>
</configuration>
</plugin>
<plugin>
<groupId>io.fabric8</groupId>
<artifactId>fabric8-maven-plugin</artifactId>
<version>${fabric8.maven.plugin.version}</version>
<executions>
<execution>
<id>fmp</id>
<goals>
<goal>resource</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build> <profiles>
<profile>
<id>kubernetes</id>
<build>
<plugins>
<plugin>
<groupId>io.fabric8</groupId>
<artifactId>fabric8-maven-plugin</artifactId>
<version>${fabric8.maven.plugin.version}</version>
<executions>
<execution>
<id>fmp</id>
<goals>
<goal>resource</goal>
<goal>build</goal>
</goals>
</execution>
</executions>
<configuration>
<enricher>
<config>
<fmp-service>
<type>NodePort</type>
</fmp-service>
</config>
</enricher>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
</project>
  1. 以上就是webdemo应用的内容了,接下来要编译、构建、部署到minikube环境,在pom.xml执行以下命令即可:
mvn clean install fabric8:deploy -Dfabric8.generator.from=fabric8/java-jboss-openjdk8-jdk -Pkubernetes

部署完成后终端输出类似如下成功信息:

[INFO]
[INFO] <<< fabric8-maven-plugin:3.5.37:deploy (default-cli) < install @ webdemo <<<
[INFO]
[INFO]
[INFO] --- fabric8-maven-plugin:3.5.37:deploy (default-cli) @ webdemo ---
[INFO] F8: Using Kubernetes at https://192.168.121.133:8443/ in namespace default with manifest /usr/local/work/k8s/webdemo/target/classes/META-INF/fabric8/kubernetes.yml
[INFO] Using namespace: default
[INFO] Updating a Service from kubernetes.yml
[INFO] Updated Service: target/fabric8/applyJson/default/service-webdemo.json
[INFO] Using namespace: default
[INFO] Updating Deployment from kubernetes.yml
[INFO] Updated Deployment: target/fabric8/applyJson/default/deployment-webdemo.json
[INFO] F8: HINT: Use the command `kubectl get pods -w` to watch your pods start up
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 11.804 s
[INFO] Finished at: 2019-07-07T21:32:26+08:00
[INFO] ------------------------------------------------------------------------
  1. 查看service和pod,确认一切正常:
[root@minikube webdemo]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 29d
webdemo NodePort 10.106.98.137 <none> 8080:30160/TCP 115m
[root@minikube webdemo]# kubectl get pod
NAME READY STATUS RESTARTS AGE
webdemo-c9f774b9-gsbgx 1/1 Running 0 3m13s
  1. 使用minikube命令取得webdemo服务对外暴露的地址:
[root@minikube webdemo]# minikube service webdemo --url
http://192.168.121.133:30160

可见外部通过地址:http://192.168.121.133:30160 即可访问到webdemo应用;

7. 在浏览器输入地址:http://192.168.121.133:30160/hello/time ,即可验证webdemo的http接口是否正常,如下图,由于header中没有extendtag属性,因此返回的extendtag为null:



至此,webdemo在minikue上已经正常运行,该开发gateway应用了;

开发k8sgatewaydemo

  1. 基于maven创建一个名为k8sgatewaydemo的springboot应用,pom.xml内容如下:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.bolingcavalry</groupId>
<artifactId>k8sgatewaydemo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>k8sgatewaydemo</name>
<description>Demo project for Spring Boot</description> <properties>
<java.version>1.8</java.version>
<spring-boot.version>2.1.6.RELEASE</spring-boot.version>
<maven-checkstyle-plugin.failsOnError>false</maven-checkstyle-plugin.failsOnError>
<maven-checkstyle-plugin.failsOnViolation>false</maven-checkstyle-plugin.failsOnViolation>
<maven-checkstyle-plugin.includeTestSourceDirectory>false</maven-checkstyle-plugin.includeTestSourceDirectory>
<maven-compiler-plugin.version>3.5</maven-compiler-plugin.version>
<maven-deploy-plugin.version>2.8.2</maven-deploy-plugin.version>
<maven-failsafe-plugin.version>2.18.1</maven-failsafe-plugin.version>
<maven-surefire-plugin.version>2.21.0</maven-surefire-plugin.version>
<fabric8.maven.plugin.version>3.5.37</fabric8.maven.plugin.version>
<springcloud.kubernetes.version>1.0.1.RELEASE</springcloud.kubernetes.version>
<spring-cloud.version>Greenwich.SR2</spring-cloud.version>
</properties> <dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency> <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-kubernetes-core</artifactId>
<version>${springcloud.kubernetes.version}</version>
</dependency> <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-kubernetes-discovery</artifactId>
<version>${springcloud.kubernetes.version}</version>
</dependency> <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-kubernetes-ribbon</artifactId>
<version>${springcloud.kubernetes.version}</version>
</dependency> <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-commons</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency> <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency> <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>
</dependencies> <dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>${spring-boot.version}</version>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin> <plugin>
<!--skip deploy -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-deploy-plugin</artifactId>
<version>${maven-deploy-plugin.version}</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${maven-surefire-plugin.version}</version>
<configuration>
<skipTests>true</skipTests>
<!-- Workaround for https://issues.apache.org/jira/browse/SUREFIRE-1588 -->
<useSystemClassLoader>false</useSystemClassLoader>
</configuration>
</plugin>
<plugin>
<groupId>io.fabric8</groupId>
<artifactId>fabric8-maven-plugin</artifactId>
<version>${fabric8.maven.plugin.version}</version>
<executions>
<execution>
<id>fmp</id>
<goals>
<goal>resource</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build> <profiles>
<profile>
<id>kubernetes</id>
<build>
<plugins>
<plugin>
<groupId>io.fabric8</groupId>
<artifactId>fabric8-maven-plugin</artifactId>
<version>${fabric8.maven.plugin.version}</version>
<executions>
<execution>
<id>fmp</id>
<goals>
<goal>resource</goal>
<goal>build</goal>
</goals>
</execution>
</executions>
<configuration>
<enricher>
<config>
<fmp-service>
<type>NodePort</type>
</fmp-service>
</config>
</enricher>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
</project>

上述pom文件中有以下几点需要注意:

第一、 依赖spring-cloud-kubernetes-core和spring-cloud-kubernetes-discovery,这样能用到spring-cloud-kubernetes提供的服务发现能力;

第二、依赖spring-cloud-starter-gateway,这样能用上SpringCloud的gateway能力;

第三、不要依赖spring-boot-starter-web,会和spring-cloud-starter-gateway冲突,启动时抛出以下异常:

2019-07-06 08:12:09.188  WARN 1 --- [           main] ConfigServletWebServerApplicationContext :
Exception encountered during context initialization -
cancelling refresh attempt:
org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'routeDefinitionRouteLocator' defined in class path resource [org/springframework/cloud/gateway/config/GatewayAutoConfiguration.class]:
Unsatisfied dependency expressed through method 'routeDefinitionRouteLocator' parameter 1;
nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'modifyRequestBodyGatewayFilterFactory' defined in class path resource [org/springframework/cloud/gateway/config/GatewayAutoConfiguration.class]:
Unsatisfied dependency expressed through method 'modifyRequestBodyGatewayFilterFactory' parameter 0;
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.http.codec.ServerCodecConfigurer' available:
expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
  1. 开发SpringCloud Gateway的启动类K8sgatewaydemoApplication.java,里面也包含了网关路由配置的实例化,除了配置路径和转发服务的关系,还在请求的header中添加了extendtag属性,请注意注释的内容:
@SpringBootApplication
@EnableDiscoveryClient
public class K8sgatewaydemoApplication { public static void main(String[] args) {
SpringApplication.run(K8sgatewaydemoApplication.class, args);
} @Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
return builder.routes()
//增加一个path匹配,以"/customize/hello/"开头的请求都在此路由
.route(r -> r.path("/customize/hello/**")
//表示将路径中的第一级参数删除,用剩下的路径与webdemo的路径做拼接,
//这里就是"lb://webdemo/hello/",能匹配到webdemo的HelloController的路径
.filters(f -> f.stripPrefix(1)
//在请求的header中添加一个key&value
.addRequestHeader("extendtag", "geteway-" + System.currentTimeMillis()))
//指定匹配服务webdemo,lb是load balance的意思
.uri("lb://webdemo")
).build();
}
}

从上述代码可见,K8sgatewaydemoApplication与普通环境下的SpringCloud Gateway并无差别,都是通过EnableDiscoveryClient注解获取服务列表,配置RouteLocator实现路由逻辑;

3. 配置文件application.yml的内容:

spring:
application:
name: gateway
cloud:
gateway:
discovery:
locator:
enabled: true
lowerCaseServiceId: true
  1. 以上就是k8sgatewaydemo应用的内容了,接下来要编译、构建、部署到minikube环境,在pom.xml执行以下命令即可:
mvn clean install fabric8:deploy -Dfabric8.generator.from=fabric8/java-jboss-openjdk8-jdk -Pkubernetes

部署完成后终端输出类似如下成功信息:

[INFO]
[INFO] <<< fabric8-maven-plugin:3.5.37:deploy (default-cli) < install @ k8sgatewaydemo <<<
[INFO]
[INFO]
[INFO] --- fabric8-maven-plugin:3.5.37:deploy (default-cli) @ k8sgatewaydemo ---
[INFO] F8: Using Kubernetes at https://192.168.121.133:8443/ in namespace default with manifest /usr/local/work/k8s/k8sgatewaydemo/target/classes/META-INF/fabric8/kubernetes.yml
[INFO] Using namespace: default
[INFO] Updating a Service from kubernetes.yml
[INFO] Updated Service: target/fabric8/applyJson/default/service-k8sgatewaydemo.json
[INFO] Using namespace: default
[INFO] Updating Deployment from kubernetes.yml
[INFO] Updated Deployment: target/fabric8/applyJson/default/deployment-k8sgatewaydemo.json
[INFO] F8: HINT: Use the command `kubectl get pods -w` to watch your pods start up
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 16.538 s
[INFO] Finished at: 2019-07-07T22:04:48+08:00
[INFO] ------------------------------------------------------------------------
  1. 查看service和pod,确认一切正常:
[root@minikube k8sgatewaydemo]# clear
[root@minikube k8sgatewaydemo]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
k8sgatewaydemo NodePort 10.97.94.238 <none> 8080:31352/TCP 129m
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 29d
webdemo NodePort 10.106.98.137 <none> 8080:30160/TCP 145m
[root@minikube k8sgatewaydemo]# kubectl get pod
NAME READY STATUS RESTARTS AGE
k8sgatewaydemo-6fbb79885c-r2jfn 1/1 Running 0 33s
webdemo-c9f774b9-gsbgx 1/1 Running 0 32m
  1. 使用minikube命令取得webdemo服务对外暴露的地址:
[root@minikube k8sgatewaydemo]# minikube service k8sgatewaydemo --url
http://192.168.121.133:31352

可见外部通过地址:http://192.168.121.133:31352 即可访问到k8sgatewaydemo应用;

7. 在浏览器输入地址:http://192.168.121.133:31352/customize/hello/time ,即可验证k8sgatewaydemo作为网关应用,能否将路径中带有customize的请求转发到webdemo应用,并且在请求header中添加名为entendtag的属性,如下图,浏览器展示的内容是webdemo的http接口返回的,并且extendtag的内容也不为空了,而是k8sgatewaydemo在转发前写入的:



上述结果表明已可以证明我们之前的推测是正确的:SpringCloud Gateway应用在使用了spring-cloud-kubernetes提供的注册发现能力后,可以将请求转发到kubernetes环境中的服务上;

也就是说,借助spring-cloud-kubernetes框架,你在SpringCloud环境开发的SpringCloud Gateway应用,可以以很小的代价迁移到kubernetes环境,与kubernetes环境中的service可以很好的交互,而原有的eureka注册中心也可以不用了;

解决权限问题

如果您的spring-cloud-kubernetes在向webdemo转发请求时抛出以下错误,那是因为遇到了kubernetes的权限问题:

2019-07-06 04:46:40.042  WARN 1 --- [erListUpdater-1] c.n.l.PollingServerListUpdater           : Failed one update cycle
io.fabric8.kubernetes.client.KubernetesClientException: Failure executing: GET at: https://10.96.0.1/api/v1/namespaces/default/endpoints/account-service. Message: Forbidden!Configured service account doesn't have access. Service account may have been revoked. endpoints "account-service" is forbidden: User "system:serviceaccount:default:default" cannot get resource "endpoints" in API group "" in the namespace "default".
at io.fabric8.kubernetes.client.dsl.base.OperationSupport.requestFailure(OperationSupport.java:476) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.OperationSupport.assertResponseCode(OperationSupport.java:413) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:381) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:344) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:313) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:296) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.BaseOperation.handleGet(BaseOperation.java:794) ~[kubernetes-client-4.1.0.jar!/:na]
at io.fabric8.kubernetes.client.dsl.base.BaseOperation.getMandatory(BaseOperation.java:210) ~[kubernetes-client-4.1.0.jar!/:na] at io.fabric8.kubernetes.client.dsl.base.BaseOperation.get(BaseOperation.java:177) ~[kubernetes-client-4.1.0.jar!/:na]
at org.springframework.cloud.kubernetes.ribbon.KubernetesServerList .getUpdatedListOfServers(KubernetesServerList.java:75) ~[spring-cloud-kubernetes-ribbon-1.0.1.RELEASE.jar!/:1.0.1.RELEASE]
at com.netflix.loadbalancer.DynamicServerListLoadBalancer.updateListOfServers(DynamicServerListLoadBalancer.java:240) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]
at com.netflix.loadbalancer.DynamicServerListLoadBalancer$1.doUpdate(DynamicServerListLoadBalancer.java:62) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]
at com.netflix.loadbalancer.PollingServerListUpdater$1.run(PollingServerListUpdater.java:116) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_191]
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_191]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_191]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_191]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_191]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_191]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]

处理方法是创建ServiceAccount对象,步骤如下:

  1. 创建名为fabric8-rbac.yaml的文件,内容如下:
# NOTE: The service account `default:default` already exists in k8s cluster.
# You can create a new account following like this:
#---
#apiVersion: v1
#kind: ServiceAccount
#metadata:
# name: <new-account-name>
# namespace: <namespace> ---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: fabric8-rbac
subjects:
- kind: ServiceAccount
# Reference to upper's `metadata.name`
name: default
# Reference to upper's `metadata.namespace`
namespace: default
roleRef:
kind: ClusterRole
name: cluster-admin
apiGroup: rbac.authorization.k8s.io
  1. 执行以下命令即可创建ServiceAccount对象:
kubectl apply -f fabric8-rbac.yaml
  1. 再在浏览器上继续刚才的验证,可以操作成功;

最后一个疑问

再回顾一下k8sgatewaydemo的开发过程,您会发现除了依赖spring-cloud-kubernetes对应的maven库,我们并没有显式调用spring-cloud-kubernetes相关的API或者做相关配置,就获取了所在kubernetes环境的原生服务,这是怎么回事呢?为何成本如此的低?

答案就在《spring-cloud-kubernetes背后的三个关键知识点》一文中,推荐您回顾一下此文。

至此,spring-cloud-kubernetes框架下的SpringCloud Gateway开发实战就完成了,希望本文能帮助您更好的理解和使用spring-cloud-kubernetes,更加高效的将应用向容器化迁移。

欢迎关注我的公众号:程序员欣宸

spring-cloud-kubernetes与SpringCloud Gateway的更多相关文章

  1. 朱晔和你聊Spring系列S1E11:小测Spring Cloud Kubernetes @ 阿里云K8S

    有关Spring Cloud Kubernates(以下简称SCK)详见https://github.com/spring-cloud/spring-cloud-kubernetes,在本文中我们主要 ...

  2. spring cloud 2.x版本 Gateway动态路由教程

    摘要 本文采用的Spring cloud为2.1.8RELEASE,version=Greenwich.SR3 本文基于前面的几篇Spring cloud Gateway文章的实现. 参考 Gatew ...

  3. spring cloud 2.x版本 Gateway熔断、限流教程

    前言 本文采用Spring cloud本文为2.1.8RELEASE,version=Greenwich.SR3 本文基于前两篇文章eureka-server.eureka-client.eureka ...

  4. spring cloud 2.x版本 Gateway路由网关教程

    前言 本文采用Spring cloud本文为2.1.8RELEASE,version=Greenwich.SR3 本文基于前两篇文章eureka-server.eureka-client.eureka ...

  5. spring cloud 2.x版本 Gateway自定义过滤器教程

    前言 本文采用Spring cloud本文为2.1.8RELEASE,version=Greenwich.SR3 本文基于前两篇文章eureka-server.eureka-client.eureka ...

  6. Spring Cloud Config整合Spring Cloud Kubernetes,在k8s上管理配置

    1 前言 欢迎访问南瓜慢说 www.pkslow.com获取更多精彩文章! Kubernetes有专门的ConfigMap和Secret来管理配置,但它也有一些局限性,所以还是希望通过Spring C ...

  7. Springboot整合Spring Cloud Kubernetes读取ConfigMap,支持自动刷新配置

    1 前言 欢迎访问南瓜慢说 www.pkslow.com获取更多精彩文章! Docker & Kubernetes相关文章:容器技术 之前介绍了Spring Cloud Config的用法,但 ...

  8. Spring Cloud Alibaba (一): SpringCloud与SpringBoot版本选型

    前言   近年SpringCloud与SpringBoot更新迭代非常频繁,导致我们对两者的版本选型非常的困难.若是版本选择有问题, 会导致开发中调试兼容性占用非常多的得必要时间. SpringClo ...

  9. spring cloud kubernetes之serviceaccount permisson报错

    spring boot项目引用spring-cloud-starter-kubernetes <dependency> <groupId>org.springframework ...

  10. 微服务Spring Cloud与Kubernetes比较

    转 http://www.tuicool.com/articles/VnMf2y3 Spring Cloud或Kubernetes都宣称它们是开发运行微服务的最好环境,哪个更好?答案是两个都是,但他们 ...

随机推荐

  1. IO-文件输出流

    一.输出流的原理 Java向文件中写数据的原理 Java程序-->JVM(java虚拟机)-->OS(操作系统)-->OS调用写数据的方法-->把数据写入到文件中 tips: ...

  2. Java基础之分支结构循环结构

    流程控制语句if(分支结构) 流程控制:流程就是指代码运行过程.控制就是说什么场景可以执行,什么场景不能执行. 1.if语句第一种形式 格式:if(表达式){      执行的语句:     } 2. ...

  3. MyBatis映射,抛出Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'oid' in 'class java.lang.String'

    原因在于: 在MyBatis中使用动态语句的判断时,传入的参数(parameterType)为Java基本数据类型,获取的结果(resultType)为JavaBean对象,此时就会抛出该异常,此时可 ...

  4. JavaWeb学习笔记—监听器

    监听器Listener是JavaWeb中的三大组件之一 按监听的对象划分,可以分为 ServletContext对象监听器 HttpSession对象监听器 ServletRequest对象监听器 按 ...

  5. 微信小程序的尺寸单位rpx介绍

    rpx单位是微信小程序中css的尺寸单位,rpx可以根据屏幕宽度进行自适应. 规定屏幕宽为750rpx.如在 iPhone6 上,屏幕宽度为375px,共有750个物理像素,则750rpx = 375 ...

  6. Nginx 的简单使用 (IIS,Asp.Net)

    Nginx 的一些常见功能(windows,AspNet ,IIS) 下载 官方网站:https://nginx.org/en/download.html 下载,解压缩是这个样子 启动: 启动方式有两 ...

  7. Code blocks返回错误代码:Process returned -1073741819 (0xC0000005)

    循环语句访问链表时,返回了错误代码: 逐项排查后,发现是由while循环引起的: 附上出错代码: do{ L=L->post; printf("%05d %d %05d\n" ...

  8. django+uwsgi+nginx 部署生产环境

    一.Uwsgi安装 python3 -m pip install uwsgi cp /usr/local/python3/bin/uwsgi /usr/bin/ 测试 在django项目主目录下cre ...

  9. 【原创】NES第一波:如何用通用型6502宏汇编器,制用NES/FC游戏。

    在163的博客关了呀.在这边重新开张了. 以后若网友有什么要长篇解答的问题,也在这儿作答. 作为第一波原创文章,我打算做一次小白示范.那就是一步一步的展示某个汇编编译器的用法. 一.科普 很多人认为程 ...

  10. HiveQL DDL 常用QL示例资料

    hive-version2.1.1 DDL操作 Create/Drop/Alter/Use Database 创建数据库 //官方指导 CREATE (DATABASE|SCHEMA) [IF NOT ...