Kubernetes微服务入门教程：部署spring-boot应用

测试如下教程时，请确认kubernates环境正常，可参考该文件搭建kubernates环境Kubernetes微服务入门教程：环境安装_jacarri的博客-CSDN博客。

创建一个Spring boot应用

 访问https://start.spring.io/创建一个最简单的 spring boot应用，如下图所示

添加测试和制作镜像的代码

添加用于测试java代码

@RestController
public class HelloWorldController {
    @RequestMapping("/")
    public String index() {
        return "Hello World\t" + new Date();
    }
}

添加用于制作镜像的文件：src/main/docker/Dockerfile,文件内容如下：

FROM openjdk:8-jdk-oracle

ADD spring-boot-demo-0.0.1-SNAPSHOT.jar /app.jar

ENV TZ=Asia/Shanghai

ENTRYPOINT [ "java", "-jar", "/app.jar" ]

在pom.xml  添加用于制作镜像的 docker-maven-plugin 插件

    
        1.8
        ${java.version}
        ${java.version}
        UTF-8
        jacarrichan
    

...
            
                com.spotify
                docker-maven-plugin
                1.2.2
                
                    
                        package
                        
                            build
                        
                    
                
                
                    ${docker.image.prefix}/${project.artifactId}
                    ${project.basedir}/src/main/docker
                    
                        ${project.version}
                        latest
                    
                    
                        
                            /
                            ${project.build.directory}
                            ${project.build.finalName}.jar
                        
                    
                
            
...

添加用于声明Kubernates服务的yml文件，内容如下：

apiVersion: v1
kind: Service
metadata:
  name: spring-boot-demo
  labels:
    app: spring-boot-demo
spec:
  type: NodePort
  ports:
  - name: http
    port: 8080
    nodePort: 30000   # 此处定义POD的端口8080映射为Node的30000
  selector:
    app: spring-boot-demo

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: spring-boot-demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: spring-boot-demo
  template:
    metadata:
      labels:
        app: spring-boot-demo
    spec:
      containers:
      - name: spring-boot-demo
        image: jacarrichan/spring-boot-demo:0.0.1-SNAPSHOT
        ports:
        - name: http
          containerPort: 8080   # 此处定义POD暴露的端口

代码打包和制作镜像

PS C:\Users\jacarrichan\temp\spring-boot-demo> mvn clean  package    -DskipTests 
[INFO] Scanning for projects...
[INFO] 
[INFO] ---------------< com.jacarrichan.demo:spring-boot-demo >----------------
[INFO] Building spring-boot-demo 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ spring-boot-demo ---
[INFO] Deleting C:\Users\jacarrichan\temp\spring-boot-demo\target
[INFO] 
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ spring-boot-demo ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ spring-boot-demo ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to C:\Users\jacarrichan\temp\spring-boot-demo\target\classes
[INFO] 
[INFO] --- maven-resources-plugin:3.2.0:testResources (default-testResources) @ spring-boot-demo ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] skip non existing resourceDirectory C:\Users\jacarrichan\temp\spring-boot-demo\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ spring-boot-demo ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to C:\Users\jacarrichan\temp\spring-boot-demo\target\test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ spring-boot-demo ---
[INFO] Tests are skipped.
[INFO]
[INFO] --- maven-jar-plugin:3.2.2:jar (default-jar) @ spring-boot-demo ---
[INFO] Building jar: C:\Users\jacarrichan\temp\spring-boot-demo\target\spring-boot-demo-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- spring-boot-maven-plugin:2.6.6:repackage (repackage) @ spring-boot-demo ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- docker-maven-plugin:1.2.2:build (default) @ spring-boot-demo ---
[INFO] Using authentication suppliers: [ConfigFileRegistryAuthSupplier]
[INFO] Copying C:\Users\jacarrichan\temp\spring-boot-demo\target\spring-boot-demo-0.0.1-SNAPSHOT.jar -> C:\Users\jacarrichan\temp\spring-boot-demo\target\docker\spring-boot-demo-0.0.1-SNAPSHOT.jar
[INFO] Copying C:\Users\jacarrichan\temp\spring-boot-demo\src\main\docker\Dockerfile -> C:\Users\jacarrichan\temp\spring-boot-demo\target\docker\Dockerfile
[INFO] Building image jacarrichan/spring-boot-demo
Step 1/4 : FROM openjdk:8-jdk-oracle

 ---> 5783fe09fd20
Step 2/4 : ADD spring-boot-demo-0.0.1-SNAPSHOT.jar /app.jar

 ---> 4c07a1a20273
Step 3/4 : ENV TZ=Asia/Shanghai

 ---> Running in cc7f05568a73
Removing intermediate container cc7f05568a73
 ---> dac566480459
Step 4/4 : ENTRYPOINT [ "java", "-jar", "/app.jar" ]

 ---> Running in a9a9088ac338
Removing intermediate container a9a9088ac338
 ---> 98cf1242fba2
ProgressMessage{id=null, status=null, stream=null, error=null, progress=null, progressDetail=null}
Successfully built 98cf1242fba2
Successfully tagged jacarrichan/spring-boot-demo:latest
[INFO] Built jacarrichan/spring-boot-demo
[INFO] Tagging jacarrichan/spring-boot-demo with 0.0.1-SNAPSHOT
[INFO] Tagging jacarrichan/spring-boot-demo with latest
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  11.186 s
[INFO] Finished at: 2022-04-10T19:42:30+08:00
[INFO] ------------------------------------------------------------------------
PS C:\Users\jacarrichan\temp\spring-boot-demo> 

确认镜像信息

在Docker Desktop中查看制作的镜像

在kubernates中运行spring-boot-demo应用

创建Pod运行应用

PS C:\Users\jacarrichan\temp\spring-boot-demo> kubectl  create    -f  .\k8s.yaml
service/spring-boot-demo created
deployment.apps/spring-boot-demo created
PS C:\Users\jacarrichan\temp\spring-boot-demo> 

查看应用运行日志日志

 获取SVC信息

PS C:\Users\jacarrichan\temp\spring-boot-demo> kubectl  get  svc
NAME               TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes         ClusterIP   10.96.0.1               443/TCP          9d
spring-boot-demo   NodePort    10.107.197.80           8080:30000/TCP   2m12s

从中可以看到spring-boot-demo 这个Service的 8080端口被映射为了30000端口。

在访问30000端口，测试链路状态信息：

查看POD 详细信息命令

PS C:\Users\jacarrichan\temp\spring-boot-demo> kubectl  get  pods
NAME                               READY   STATUS    RESTARTS   AGE
spring-boot-demo-d8bdc7896-7d4l4   1/1     Running   0          7m39s
PS C:\Users\jacarrichan\temp\spring-boot-demo> kubectl  describe  pod spring-boot-demo-d8bdc7896-7d4l4 
Name:         spring-boot-demo-d8bdc7896-7d4l4
Namespace:    default
Priority:     0
Node:         docker-desktop/192.168.65.4
Start Time:   Sun, 10 Apr 2022 19:46:15 +0800
Labels:       app=spring-boot-demo
              pod-template-hash=d8bdc7896
Annotations:  
Status:       Running
IP:           10.1.1.188
IPs:
  IP:           10.1.1.188
Controlled By:  ReplicaSet/spring-boot-demo-d8bdc7896
Containers:
  spring-boot-demo:
    Container ID:   docker://e05adb4204782ab6851e86eb6eee97e2fc9027cf4bcac405acf3d3c0bcf0d821
    Image:          jacarrichan/spring-boot-demo:0.0.1-SNAPSHOT
    Image ID:       docker://sha256:98cf1242fba27986e06b26549d42417af93bf6a313d3490ef6a844507d0546f4
    Port:           8080/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Sun, 10 Apr 2022 19:46:16 +0800
    Ready:          True
    Restart Count:  0
    Environment:    
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-mgdks (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  kube-api-access-mgdks:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       
    DownwardAPI:             true
QoS Class:                   BestEffort
Node-Selectors:              
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason     Age    From               Message
  ----    ------     ----   ----               -------
  Normal  Scheduled  7m42s  default-scheduler  Successfully assigned default/spring-boot-demo-d8bdc7896-7d4l4 to docker-desktop
  Normal  Pulled     7m42s  kubelet            Container image "jacarrichan/spring-boot-demo:0.0.1-SNAPSHOT" already present on machine
  Normal  Created    7m42s  kubelet            Created container spring-boot-demo
  Normal  Started    7m42s  kubelet            Started container spring-boot-demo

本教程中涉及到的代码可从此处获取：

https://github.com/jacarrichan/spring-boot-kubernetes-demo