操作步骤
- windows上编写代码
- 远程linux的docker引擎把代码打成镜像
- 编写k8s的yaml文件
- 应用yaml文件,启动服务
前置任务
- 安装好k8s集群,可参考另一篇文章:Centos7安装k8s集群1.15.0版本
一. 基于springboot编写hello world代码
1. 代码结构
2. pom文件
<?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>
<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.kinnylee</groupId>
<artifactId>k8s-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>k8s-demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<docker.image.prefix>kinnylee</docker.image.prefix>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</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-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<!--编译打包成镜像-->
<build>
<resources>
<resource>
<directory>src/main/docker</directory>
<filtering>true</filtering>
<includes>
<include>**/Dockerfile</include>
</includes>
<targetPath>../docker</targetPath>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>com.spotify</groupId>
<artifactId>dockerfile-maven-plugin</artifactId>
<version>1.4.0</version>
<configuration>
<!-- <repository>${docker.image.prefix}/${project.artifactId}</repository>-->
<repository>${project.artifactId}</repository>
<tag>${project.version}</tag>
<buildArgs>
<JAR_FILE>target/${project.build.finalName}.jar</JAR_FILE>
</buildArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>
3. Dockerfile文件
FROM openjdk:8-jdk-alpine
ENV TIME_ZONE Asia/Shanghai
RUN apk add --no-cache tzdata && \
echo "${TIME_ZONE}" > /etc/timezone && ln -sf /usr/share/zoneinfo/${TIME_ZONE} /etc/localtime
VOLUME /data
ARG JAR_FILE
ADD ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
4. controller文件
package com.kinnylee.k8sdemo.controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class K8sDemoController {
@GetMapping("/hello")
public String hello(){
return "hello k8s demo.";
}
}
二. 打包成镜像
如果在liunx下安装idea开发,下面的步骤可省略,直接编译打包即可
liunx下安装IDE比较卡,windows下安装docker兼容性不好。于是采用windows编写代码,远程连接linux中docker放开的TCP端口,进行远程镜像打包
1. 配置远程docker的TCP连接
vim /lib/systemd/system/docker.service
# ExecStart结尾添加:-H tcp://0.0.0.0:2375
[Service]
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock -H tcp://0.0.0.0:2375
2. IDEA中设置Docker执行的远程地址
3. 环境变量中添加DOCKER_HOST
工具名称:Rapid Environment
4. 开始编译打包成镜像
5. 编译成功后的镜像
6. linux上验证正确性
7. 将镜像拷贝到其他节点(有私仓则直接push发布,不需要这一步)
# 保存镜像
docker save k8s-demo:0.0.1-SNAPSHOT -o k8s-demo.tar
# 镜像拷贝到其他机器
scp k8s-demo.tar 10.1.69.100:/data/images
scp k8s-demo.tar 10.1.69.102:/data/images
scp k8s-demo.tar 10.1.69.103:/data/images
# 其他节点上分别执行以下命令,恢复镜像
cd /data/images
docker load < k8s-demo.tar
三. 编写k8s的yaml文件
Deployment
- deployment.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: k8s-demo
namespace: spring-test
spec:
replicas: 3
template:
metadata:
labels:
app: k8s-demo
spec:
containers:
- name: k8s-demo
image: kinnylee/k8s-demo:0.0.1-SNAPSHOT
ports:
containerPort: 8080
Service
apiVersion: v1
kind: Service
metadata:
name: k8s-demo
namespace: spring-test
spec:
type: NodePort
selector:
app: k8s-demo
ports:
- protocol: TCP
port: 8888
targetPort: 8080
nodePort: 30003
四. 开始部署到k8s
1. 创建namespace
# 创建命名空间
kubectl create namespace spring-test
# 验证是否成功
kubectl get ns
2. 创建deployment
# 开始创建deployment
kubectl apply -f deployment.yaml
# 验证是否创建成功
kubectl get deployment -n spring-test
# 验证3个pod是否创建成功
kubectl get pods -n spring-test
# 如果启动不成功,排查原因,pod后面的参数为上一步查询的pod名称
kubectl describe pod k8s-demo-f99976b78-5blxd -n spring-test
3. 创建service
# 创建service
kubectl apply -f service.yaml
# 验证是否创建成功
kubectl get svc -n spring-test
4. 外部访问服务
- 如下图:输入k8s节点ip和30003端口号,就可以看到服务可以被访问到了