k8s 使用configmap存储项目配置文件

1. 编写配置文件yaml

• 编写configmap配置文件

  [root@k8s-master java-demo]# vim  configmap.yaml 
  [root@k8s-master java-demo]# cat configmap.yaml 
  apiVersion: v1
  kind: ConfigMap
  metadata:
    name: java-demo-config     # 应用卷的名字
  data:
      application.yml: |
          server:
            port: 8080
          spring:
            datasource:
              url: jdbc:mysql://121.4.77.138:3306/java_demo?characterEncoding=utf-8
              username: java_demo
              password: Aa@9953013
              driver-class-name: com.mysql.jdbc.Driver
            freemarker:
              allow-request-override: false
              cache: true
              check-template-location: true
              charset: UTF-8
              content-type: text/html; charset=utf-8
              expose-request-attributes: false
              expose-session-attributes: false
              expose-spring-macro-helpers: false
              suffix: .ftl
              template-loader-path:
                - classpath:/templates/
  

• 应用配置文件

  [root@k8s-master java-demo]# kubectl apply -f configmap.yaml 
  configmap/java-demo-config created
  

2. 把configmap里的配置文件，放到应用程序里面

• 编写应用配置文件yaml

  [root@k8s-master java-demo]# vim java_demo.yaml 
  [root@k8s-master java-demo]# cat java_demo.yaml 
  

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: java-demo
    namespace: default
    labels:
      app: java-demo
    annotations:       # 记录回滚参数
      kubernetes.io/change-cause: "java-demo:v1"   #记录到revision中的内容，记录版本号
  spec:
    replicas: 3 # Pod副本预期数量
    revisionHistoryLimit: 10 # RS历史版本保存数量
    selector:
      matchLabels:
        app: java-demo
    strategy:
      rollingUpdate:
        maxSurge: 25%             # 滚动更新过程最大pod副本数
        maxUnavailable: 25%       # 滚动更新过程中最大不可用pod副本数，
      type: RollingUpdate
    template:
      metadata:
        labels:
          app: java-demo # Pod副本的标签
      spec:
        imagePullSecrets:
        - name: harbor-auth
        containers:
        - name: java-demo
          image: harbor.scajy.org/scajy/java:v1         # 获取容器
          ports:
          - containerPort: 8080
          resources:
            requests:              # 启动容器最小资源
              memory: "256Mi"
              cpu: "500m"
            limits:                 # 容器的最大资源限制
              memory: "512Mi"       # 容器的最大资源内存限制128M
              cpu: "1000m"           # 容器的最大资源cpu的核数限制，500m=0.5核数
          readinessProbe:          # 存活检查,如果失败，将杀死容器，来重启
            httpGet:
              port: 8080
              path: /
            initialDelaySeconds: 20 #启动容器后多少秒健康检查
            periodSeconds: 20 #以后间隔多少秒检查一次
          livenessProbe:   # 就绪检查，失败就会剔除 service 
            httpGet:
              port: 8080
              path: /
          volumeMounts:
          - name: config       # 指定共享卷的名称
            mountPath: "/usr/local/tomcat/webapps/ROOT/WEB-INF/classes/application.yml"    # 指定挂载目录下
            subPath: application.yml     # 指定文件名称
        volumes:
        - name: config
          configMap:
            name: java-demo-config        # 指定configmap的卷名
            items:
            - key: "application.yml"      # 指定的configmap的data里的保存的文件名
              path: "application.yml"     # 指定configmap的data文件
  
  

• 启动配置文件

  [root@k8s-master java-demo]# kubectl apply -f java_demo.yaml 
  deployment.apps/java-demo configured
  

• 查看应用

  [root@k8s-master java-demo]# kubectl get pods
  NAME                         READY   STATUS             RESTARTS   AGE
  java-demo-747ff448bd-tg79z   1/1     Running            0          31m
  java-demo-747ff448bd-xcn26   1/1     Running            0          31m
  java-demo-758759777d-xtqfq   0/1     CrashLoopBackOff   11         24m
  nginx-6799fc88d8-bvg8q       1/1     Running            0          2d