【7年工作-Java技术栈整理】——容器化编排技术K8S——单机版K8S最简安装 【练手k8s必备】

 

1 . kubernetes单机版搭建

一、实验环境

虚拟机vmware：Centos7
ip：192.168.146.132
内存：1G
硬盘：20G

二、kubernetes单机版环境搭建

1、关闭CentOS自带的防火墙

systemctl disable firewalld
systemctl stop firewalld

2、安装etcd和Kubernetes软件（会自动安装Docker软件）

yum install -y etcd kubernetes

3、修改配置文件

修改/etc/sysconfig/docker,修改为：

OPTIONS='--selinux-enabled=false --insecure-registry gcr.io'

Kubernetes apiserver配置文件/etc/kubernetes/apiserver中，把--admission_control参数中的ServiceAccount删除

4、配置CentOS证书

参考内容:Kubernetes创建pod一直处于ContainerCreating排查和解决
因为拉取gcr.io的镜像需要redhat的证书，但是系统默认是没有的，所以，这里我们自己添加。

安装rhsm

yum install -y *rhsm*

通过python-rhsm-certificates的rpm包获得证书：

wget http://mirror.centos.org/centos/7/os/x86_64/Packages/python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm

rpm2cpio python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm | cpio -iv --to-stdout ./etc/rhsm/ca/redhat-uep.pem | tee /etc/rhsm/ca/redhat-uep.pem

安装完成后，执行一下docker pull registry.access.redhat.com/rhel7/pod-infrastructure:latest

5、配置docker阿里云镜像加速

这个镜像仓库是我个人在阿里云申请的：

mkdir -p /etc/docker

tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://ckq4qobq.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

systemctl deamon-reload
systemctl restart docker

6、启动所有服务

systemctl  start etcd
systemctl start docker
systemctl start kube-apiserver
systemctl start kube-controller-manager
systemctl start kube-scheduler
systemctl start kubelet
systemctl start kube-proxy

三、搭建服务

从github上下载需要的yaml文件：
需要用到的是 java_web_app 文件夹内内容
下载地址：https://github.com/bestlope/k8s_practice
或者：git clone https://github.com/bestlope/k8s_practice.git

1、搭建mysql服务

cd k8s_practice/java_web_app/mysql

#启动mysql的RC服务
kubectl create -f mysql-rc.yaml

#查看刚刚创建的RC
kubectl get rc

#查看pod创建的情况
kubectl get pods

#启动mysql的SVC服务
kubectl create -f mysql-svc.yml

#查看刚刚创建的service
kubectl get svc

2、启动tomcat应用

cd k8s_practice/java_web_app/tomcat

#创建tomcat的RC服务
kubectl create -f myweb-rc.yaml

#创建tomcat的SVC服务
kubectl create -f myweb-svc.yaml

3、通过浏览器访问网页

访问：http://192.168.146.132:30001/

成功看到跳转到Tomcat页面，即成功单机版 K8S 搭建。

2. 部署一个spring-boot项目

      开发一个spring boot 项目 基于JPA操作MySQL的CRUD.

      项目目录结构如下：

       

核心配置文件： 

Dockerfile：

FROM openjdk:8-jdk-alpine
#将本地文件挂到到/tmp目录
VOLUME /tmp
#复制文件到容器
ADD spring-boot-docker-1.0.jar /app.jar
#暴露8080端口
EXPOSE 8081
#配置启动容器后执行的命令
ENTRYPOINT ["java","-jar","/app.jar"]

k8s-app-mysql.yaml 

apiVersion: v1
kind: Service
metadata:
  name: k8s-app
  namespace: default
  labels:
    app: k8s-app
spec:
  type: NodePort
  ports:
  - port: 8081
    nodePort: 30002
  selector:
    app: k8s-app

---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: k8s-app
  labels:
    app: k8s-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: k8s-app
  template:
    metadata:
      labels:
        app: k8s-app
    spec:
      containers:
      - name: k8s-app
        image: k8s-mysql:latest
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8081
        livenessProbe:
          httpGet:
            port: 8081
            path: /
            scheme: HTTP
          periodSeconds: 15
          initialDelaySeconds: 30

 pom.xml : 配置项目依赖与Docker插件

<?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>

	<groupId>com.neo</groupId>
	<artifactId>spring-boot-docker</artifactId>
	<version>1.0</version>
	<packaging>jar</packaging>

	<name>spring-boot-docker</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.0.RELEASE</version>
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<java.version>1.8</java.version>
		<docker.image.prefix>springboot</docker.image.prefix>
	</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-data-jpa</artifactId>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.34</version>
		</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>
			</plugin>
			<!-- Docker maven plugin -->
			<plugin>
				<groupId>com.spotify</groupId>
				<artifactId>docker-maven-plugin</artifactId>
				<version>1.0.0</version>
				<configuration>
					<imageName>${docker.image.prefix}/${project.artifactId}</imageName>
					<dockerDirectory>src/main/docker</dockerDirectory>
					<resources>
						<resource>
							<targetPath>/</targetPath>
							<directory>${project.build.directory}</directory>
							<include>${project.build.finalName}.jar</include>
						</resource>
					</resources>
				</configuration>
			</plugin>
			<!-- Docker maven plugin -->
		</plugins>
	</build>
	

</project>

 后台部署：

 docker build -t k8s-mysql . 构建镜像

docker images  查询构建的镜像

kubectl create -f k8s-app-mysql.yaml 创建k8s管理的service 、deployment 对外暴露服务

   最终效果先展示一下：