spring-cloud-kubernetes与SpringCloud Gateway

org.springframework.boot

spring-boot-starter-test

test

org.springframework.boot

spring-boot-maven-plugin

${spring-boot.version}

repackage

org.apache.maven.plugins

maven-deploy-plugin

${maven-deploy-plugin.version}

true

org.apache.maven.plugins

maven-surefire-plugin

${maven-surefire-plugin.version}

true

false

io.fabric8

fabric8-maven-plugin

${fabric8.maven.plugin.version}

fmp

resource

kubernetes

io.fabric8

fabric8-maven-plugin

${fabric8.maven.plugin.version}

fmp

resource

build

NodePort

4. 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] ------------------------------------------------------------------------

5. 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 10.96.0.1 443/TCP 29d

webdemo NodePort 10.106.98.137 8080:30160/TCP 115m

[root@minikube webdemo]# kubectl get pod

NAME READY STATUS RESTARTS AGE

webdemo-c9f774b9-gsbgx 1/1 Running 0 3m13s

6. 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”>

4.0.0

org.springframework.boot

spring-boot-starter-parent

2.1.6.RELEASE

com.bolingcavalry

k8sgatewaydemo

0.0.1-SNAPSHOT

k8sgatewaydemo

Demo project for Spring Boot

<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>

org.springframework.cloud

spring-cloud-starter-gateway

org.springframework.boot

spring-boot-starter-test

test

org.springframework.cloud

spring-cloud-kubernetes-core

${springcloud.kubernetes.version}

org.springframework.cloud

spring-cloud-kubernetes-discovery

${springcloud.kubernetes.version}

org.springframework.cloud

spring-cloud-starter-kubernetes-ribbon

${springcloud.kubernetes.version}

org.springframework.cloud

spring-cloud-commons

org.springframework.boot

spring-boot-starter

org.springframework.cloud

spring-cloud-starter-netflix-ribbon

org.springframework.cloud

spring-cloud-starter-netflix-hystrix

org.springframework.cloud

spring-cloud-dependencies

${spring-cloud.version}

pom

import

org.springframework.boot

spring-boot-maven-plugin

${spring-boot.version}

repackage

org.apache.maven.plugins

maven-deploy-plugin

${maven-deploy-plugin.version}

true

org.apache.maven.plugins

maven-surefire-plugin

${maven-surefire-plugin.version}

true

<! 《一线大厂Java面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 – Workaround for https://issues.apache.org/jira/browse/SUREFIRE-1588 -->

false

io.fabric8

fabric8-maven-plugin

${fabric8.maven.plugin.version}

fmp

resource

kubernetes

io.fabric8

fabric8-maven-plugin

${fabric8.maven.plugin.version}

fmp

resource

build

NodePort

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: {}

2. 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

4. 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]