一、实验configMap 和 hostPath挂载

1.创建configmap

一般情况，很少选用hostPath挂载外部配置文件的方式（有特殊需求除外），一般会选用configMap方式。
所以多数企业选用configMap资源类型挂载外部配置文件的方式：

apiVersion: v1
data:
  app.conf: |
    appname = go-dingding
    httpport = 8096
    runmode = prod
    copyrequestbody = true
    EnableDocs = true
    sessionon = true
    log_level = debug
    DingtalkURL = "https://oapi.dingtalk.com/robot/send?access_token=xxxxxx"
    DingtalkName = "dingding"
kind: ConfigMap
metadata:
  name: go-dingding-cm
  namespace: learn

实操提示：ConfigMap挂载配置文件，需写全配置参数，因为挂载到POD里只有ConfigMap，没有默认配置参数

# 创建configMap，简称CM
kubectl apply -f go-dingding-cm.yaml # 创建成功，查看CM
kubectl get cm -o wide -n learn
kubectl get cm go-dingding-cm -o yaml -n learn

创建工作负载，并挂载configmap和宿主机目录

创建deployment和serivce
2.deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    name: go-dingding
    version: 1.0.0
  name: go-dingding
  namespace: learn
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: go-dingding
      version: 1.0.0
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        name: go-dingding
        version: 1.0.0
    spec:
      containers:
      - env:
        - name: dingding-config
          value: /learn/config/config.json
        image: registry.yunlearn.org:5000/release/go-dingding:test
        imagePullPolicy: Always
        name: go-dingding
        ports:
        - containerPort: 8096
          protocol: TCP
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /app/conf/
          name: app-conf
        - mountPath: /learn/config
          name: dingding-config
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
      volumes:
      - configMap:
          defaultMode: 420
          name: go-dingding-cm
        name: app-conf
      - hostPath:
          path: /data/go-dingding/config
          type: ""
        name: dingding-config

3.servcie

apiVersion: v1
kind: Service
metadata:
  name: go-dingding
  namespace: learn
  labels:
     name: go-dingding
spec:
  type: NodePort
  ports:
  - name: http
    nodePort: 8096
    port: 8096
    protocol: TCP
    targetPort: 8096
  selector:
    name: go-dingding

二、实验secret挂载

1.选用docker私有镜像仓库docker证书做案例，创建新secret

cd /root/kubeadm/registry
kubectl create secret -n learn generic secret-cert --from-file=./docker.key --from-file=./docker.csr --from-file=./docker.crt

2.在kubernetes集群启动一个使用secret应用POD，验证应用POD运行状态和日志

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    name: secret-cert
    version: 1.0.0
  name: secret-cert
  namespace: learn
spec:
  replicas: 1
  selector:
    matchLabels:
       name: secret-cert
       version: 1.0.0
  strategy:
    rollingUpdate:
       maxSurge: 1
       maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
       creationTimestamp: null
       labels:
          name: secret-cert
          version: 1.0.0
    spec:
       containers:
       - env:
         image: registry.yunlearn.org:5000/release/nginx:1.19.6
         imagePullPolicy: Always
         name: secret-cert
         ports:
         - containerPort: 8089
           protocol: TCP
         resources: {}
         terminationMessagePath: /dev/termination-log
         terminationMessagePolicy: File
         volumeMounts:
         - mountPath: /etc/nginx/cert
           name: secret-cert
       dnsPolicy: ClusterFirst
       restartPolicy: Always
       schedulerName: default-scheduler
       securityContext: {}
       terminationGracePeriodSeconds: 30
       volumes:
       - name: secret-cert
         secret:
           defaultMode: 420
           secretName: secret-cert