当初比拟多的互联网公司都在尝试将微服务迁到云上，这样的可能通过一些成熟的云容器治理平台更为不便地治理微服务集群，从而进步微服务的稳定性，同时也能较好地晋升团队开发效率。
然而迁云存在肯定的技术难点，明天这篇文章次要介绍如何从0开始搭建一套基于K8s部署的SpringBoot案例教程。
根底环境筹备：
- mac操作系统
- SpringBoot的简略Web工程
minikube的环境搭建
装置一个适宜咱们高级入门的k8s环境，比拟好的举荐是应用minikube工具，同时应用该工具能够更好地升高咱们对k8s的学习门槛。首先咱们须要下载minikube文件：
curl -Lo minikube https://github.com/kubernetes/minikube/releases/download/v1.5.0/minikube-linux-amd64 && chmod +x minikube && sudo mv minikube /usr/local/bin/在装置minikube的时候，尝试下载镜像的时候可能会卡住，例如呈现下边的这类异样：
【idea @ Mac】>>>>>>minikube start --registry-mirror=https://w4i0ckag.mirror.aliyuncs.com Darwin 10.15.3 上的 minikube v1.16.0✨ 依据现有的配置文件应用 docker 驱动程序 Starting control plane node minikube in cluster minikube Pulling base image ...E0126 17:03:30.131026 34416 cache.go:180] Error downloading kic artifacts: failed to download kic base image or any fallback image Creating docker container (CPUs=2, Memory=1988MB) ... StartHost failed, but will try again: creating host: create: creating: setting up container node: preparing volume for minikube container: docker run --rm --entrypoint /usr/bin/test -v minikube:/var gcr.io/k8s-minikube/kicbase:v0.0.15-snapshot4@sha256:ef1f485b5a1cfa4c989bc05e153f0a8525968ec999e242efff871cbb31649c16 -d /var/lib: exit status 125stdout:stderr:Unable to find image 'gcr.io/k8s-minikube/kicbase:v0.0.15-snapshot4@sha256:ef1f485b5a1cfa4c989bc05e153f0a8525968ec999e242efff871cbb31649c16' locallydocker: Error response from daemon: Get https://gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers).See 'docker run --help'. docker "minikube" container is missing, will recreate. Creating docker container (CPUs=2, Memory=1988MB) ... Failed to start docker container. Running "minikube delete" may fix it: recreate: creating host: create: creating: setting up container node: preparing volume for minikube container: docker run --rm --entrypoint /usr/bin/test -v minikube:/var gcr.io/k8s-minikube/kicbase:v0.0.15-snapshot4@sha256:ef1f485b5a1cfa4c989bc05e153f0a8525968ec999e242efff871cbb31649c16 -d /var/lib: exit status 125stdout:stderr:Unable to find image 'gcr.io/k8s-minikube/kicbase:v0.0.15-snapshot4@sha256:ef1f485b5a1cfa4c989bc05e153f0a8525968ec999e242efff871cbb31649c16' locallydocker: Error response from daemon: Get https://gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers).See 'docker run --help'.❌ Exiting due to GUEST_PROVISION: Failed to start host: recreate: creating host: create: creating: setting up container node: preparing volume for minikube container: docker run --rm --entrypoint /usr/bin/test -v minikube:/var gcr.io/k8s-minikube/kicbase:v0.0.15-snapshot4@sha256:ef1f485b5a1cfa4c989bc05e153f0a8525968ec999e242efff871cbb31649c16 -d /var/lib: exit status 125stdout:stderr:Unable to find image 'gcr.io/k8s-minikube/kicbase:v0.0.15-snapshot4@sha256:ef1f485b5a1cfa4c989bc05e153f0a8525968ec999e242efff871cbb31649c16' locallydocker: Error response from daemon: Get https://gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers).See 'docker run --help'. If the above advice does not help, please let us know: https://github.com/kubernetes/minikube/issues/new/choose此时能够尝试先在宿主机上安装好对应的镜像文件：
docker pull anjone/kicbase而后minikube在启动的时候应用本地的镜像，这样能够缩小minikube start过程的耗时。minikube下载了之后便到了启动环节：
minikube start --vm-driver=docker --base-image="anjone/kicbase"如果启动失败，无妨试试更换指定的镜像仓库，例如下边这段：
minikube start --registry-mirror=https://bmtb46e4.mirror.aliyuncs.com --vm-driver=docker --base-image="anjone/kicbase" --image-repository=registry.cn-hangzhou.aliyuncs.com/google_containers这里头我大略介绍一下启动参数的含意：
--registry-mirror这里的地址会和启动的minikube外部的docker.daemon文件中所指向的镜像仓库地址统一。--vm-driver虚拟机引擎 这里是指minikube的外部通过docker来作为外围--base-image申明好根底镜像，如果宿主机外部有对应镜像，就不须要额定拉取--image-repository拉取镜像的仓库
当minikube启动胜利之后，大抵如下所示：
【idea @ Mac】>>>>>>minikube start --vm-driver=docker --base-image="anjone/kicbase" Darwin 10.15.3 上的 minikube v1.16.0✨ 依据现有的配置文件应用 docker 驱动程序 Starting control plane node minikube in cluster minikube docker "minikube" container is missing, will recreate. Creating docker container (CPUs=2, Memory=1988MB) ...❗ This container is having trouble accessing https://k8s.gcr.io To pull new external images, you may need to configure a proxy: https://minikube.sigs.k8s.io/docs/reference/networking/proxy/ 正在 Docker 19.03.2 中筹备 Kubernetes v1.20.0… ▪ Generating certificates and keys ... ▪ Booting up control plane ...\ ▪ Configuring RBAC rules ... Verifying Kubernetes components... Enabled addons: default-storageclass Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default【idea @ Mac】>>>>>>好了，接下来便到了部署SpringBoot利用的局部了。
基于SpringBoot部署到k8s中
首先咱们须要搭建一个简略的SpringBoot利用：
引入dependency依赖
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency></dependencies>打包docker镜像的配置：
<build> <finalName>打包进去的镜像名称</finalName> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.2.5.RELEASE</version> </plugin> <!-- Docker maven plugin --> <plugin> <groupId>com.spotify</groupId> <artifactId>docker-maven-plugin</artifactId> <version>1.0.0</version> <configuration> <imageName>${project.artifactId}</imageName> <imageTags> <tag>1.0.1</tag> </imageTags> <dockerDirectory>src/main/docker</dockerDirectory> <resources> <resource> <targetPath>/</targetPath> <directory>${project.build.directory}</directory> <include>${project.build.finalName}.jar</include> </resource> </resources> </configuration> </plugin> <!-- Docker maven plugin --> </plugins></build>接着是简略的controller和启动类：
@RestController@RequestMapping(value = "/test")public class TestController { @GetMapping(value = "/do-test") public String doTest(){ System.out.println("this is a test"); return "success"; }}@SpringBootApplicationpublic class WebApplication { public static void main(String[] args) { SpringApplication.run(WebApplication.class); }}编写Dockerfile的脚本：
FROM openjdk:8-jdk-alpineVOLUME /tmp#将springboot-k8s-template.jar复制到容器外部 并且别名叫springboot-k8s-template-v1.jarADD springboot-k8s-template.jar springboot-k8s-template-v1.jar#相当于在容器中用cmd命令执行jar包 指定内部配置文件ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/springboot-k8s-template-v1.jar"]而后进入到Dockerfile的目录底下，进行镜像的构建：
【idea @ Mac】>>>>>>docker build -t springboot-k8s-template:1.0 .[+] Building 0.5s (7/7) FINISHED => [internal] load build definition from Dockerfile 0.0s => => transferring dockerfile: 419B 0.0s => [internal] load .dockerignore 0.0s => => transferring context: 2B 0.0s => [internal] load metadata for docker.io/library/openjdk:8-jdk-alpine 0.0s => [internal] load build context 0.3s => => transferring context: 17.60MB 0.3s => CACHED [1/2] FROM docker.io/library/openjdk:8-jdk-alpine 0.0s => [2/2] ADD springboot-k8s-template.jar springboot-k8s-template-v1.jar 0.1s => exporting to image 0.1s => => exporting layers 0.1s => => writing image sha256:86d02961c4fa5bb576c91e3ebf031a3d8b140ddbb451b9613a2c4d601ac4d853 0.0s => => naming to docker.io/library/springboot-k8s-template:1.0 0.0sUse 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them【idea @ Mac】>>>>>>docker images | grep templatespringboot-k8s-template 1.0 86d02961c4fa 48 seconds ago 122MB构建实现之后，将本地镜像打包公布到镜像仓库中，这里我是通过推送到阿里云镜像仓库的形式来解决的。
举荐：Spring 高级源码全家桶
推送本地镜像到阿里云
首先是登录到docker仓库，而后记录对应的tag信息，最终推送镜像。
$ docker login --username=[阿里云账户名称] registry.cn-qingdao.aliyuncs.com$ docker tag [ImageId] registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:[镜像版本号]$ docker push registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:[镜像版本号]例如：
【idea @ Mac】>>>>>>docker images | grep configqiyu-framework-k8s-config 1.0 6168639757e9 2 minutes ago 122MB【idea @ Mac】>>>>>>docker tag 6168639757e9 registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:qiyu-framework-k8s-config-1.0【idea @ Mac】>>>>>>docker push registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:qiyu-framework-k8s-config-1.0The push refers to repository [registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp]1ace00556b41: Pushed ceaf9e1ebef5: Layer already exists 9b9b7f3d56a0: Layer already exists f1b5933fe4b5: Layer already exists qiyu-framework-k8s-config-1.0: digest: sha256:50c1a87484f6cbec699d65321fa5bbe70f5ad6da5a237e95ea87c7953a1c80da size: 1159【idea @ Mac】>>>>>>请依据理论镜像信息替换示例中的[ImageId]和[镜像版本号]参数。
将镜像文件打包并且推送到镜像仓库之后，能够通过在yaml文件中编写对应的镜像地址，这样就能保障在镜像下载的时候能从仓库拉取出对应的镜像文件。
通常我的项目中咱们会采纳对立的yaml文件来进行pod节点的部署与构建。
yaml配置文件：
apiVersion: apps/v1 #kubectl api-versions 能够通过这条指令去看版本信息kind: Deployment # 指定资源类别metadata: #资源的一些元数据 name: springboot-k8s-template-deployment #deloyment的名称 labels: app: springboot-k8s-template-deployment #标签spec: replicas: 2 #创立pod的个数 selector: matchLabels: app: springboot-k8s-template-deployment #满足标签为这个的时候相干的pod能力被调度到 template: metadata: labels: app: springboot-k8s-template-v1 spec: containers: - name: springboot-k8s-template-v1 image: registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:1.0 imagePullPolicy: IfNotPresent ports: - containerPort: 8080因为阿里云的镜像仓库须要用户账号密码权限拜访，所以这里咱们能够尝试简略一些的策略，登录minikube的外部，提前下载好对应的阿里云镜像。
通过 minikube ssh 指令即可登录到minikube的外部：
采纳docker pull指令即可下载对应资源：
docker@minikube:~$ docker pull registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:springboot-k8s-template-1.0springboot-k8s-template-1.0: Pulling from idea_hub/idea_respe7c96db7181b: Already existsf910a506b6cb: Already existsc2274a1a0e27: Already existsd2fe98fe1e4e: Pull completeDigest: sha256:dc1c9caa101df74159c1224ec4d7dcb01932aa8f4a117bba603ffcf35e91c60cStatus: Downloaded newer image for registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:springboot-k8s-template-1.0registry.cn-qingdao.aliyuncs.com/idea_hub/idea_resp:springboot-k8s-template-1.0docker@minikube:~$查看对应的镜像文件
镜像拉取策略能够对照官网的介绍来零碎意识：
https://kubernetes.io/docs/co...
在yaml文件里我选用了IfNotPresent策略，这条策略可能保障当本地有镜像的时候优先选用本地，没有才选择网络拉取。
最初是找到相干的yaml文件进行pod的部署启动。
kubectl create -f ./k8s-springboot-template.yaml 此时通过 kubectl get pod 命令能够看到对应的pod节点：
最终须要裸露deployment服务：
【idea @ 拍了拍我的iterm2 说】>>>>>> kubectl expose deployment springboot-k8s-template-deployment --type=NodePortservice/springboot-k8s-template-deployment exposed【idea @ 拍了拍我的iterm2 说】>>>>>> kubectl get podsNAME READY STATUS RESTARTS AGEspringboot-k8s-template-deployment-687f8bf86d-gqxcp 1/1 Running 0 7m50sspringboot-k8s-template-deployment-687f8bf86d-lcq5p 1/1 Running 0 7m50s【idea @ 拍了拍我的iterm2 说】>>>>>> minikube service springboot-k8s-template-deployment|-----------|------------------------------------|-------------|---------------------------|| NAMESPACE | NAME | TARGET PORT | URL ||-----------|------------------------------------|-------------|---------------------------|| default | springboot-k8s-template-deployment | 8080 | http://192.168.49.2:31179 ||-----------|------------------------------------|-------------|---------------------------| Starting tunnel for service springboot-k8s-template-deployment.|-----------|------------------------------------|-------------|------------------------|| NAMESPACE | NAME | TARGET PORT | URL ||-----------|------------------------------------|-------------|------------------------|| default | springboot-k8s-template-deployment | | http://127.0.0.1:57109 ||-----------|------------------------------------|-------------|------------------------| 正通过默认浏览器关上服务 default/springboot-k8s-template-deployment...❗ Because you are using a Docker driver on darwin, the terminal needs to be open to run it.裸露之后拜访：
http://127.0.0.1:57109/test/do-test验证接口失常。
minikube日志查看：
kubectl logs -f springboot-k8s-template-deployment-687f8bf86d-lcq5p