Kubernetes K8S之存储ConfigMap详解

深碍√TFBOYSˉ_ 2022-12-27 08:35 162阅读 0赞

### Kubernetes K8S之存储ConfigMap详解 ###

*  ConfigMap概述
 *  ConfigMap创建方式
 *   *  通过目录创建
     *  通过文件创建
     *  通过命令行创建
     *  通过yaml文件创建
 *  Pod中使用ConfigMap
 *   *  当前存在的ConfigMap
     *  使用ConfigMap来替代环境变量
     *  使用ConfigMap设置命令行参数
     *  通过数据卷插件使用ConfigMap【推荐】
 *  ConfigMap热更新
 *   *  准备工作
     *  热更新

相关内容原文链接：  
[Kubernetes K8S之存储ConfigMap详解][Kubernetes K8S_ConfigMap]

# ConfigMap概述 #

ConfigMap 是一种 API 对象，用来将非机密性的数据保存到健值对中。使用时可以用作环境变量、命令行参数或者存储卷中的配置文件。

ConfigMap 将环境配置信息和容器镜像解耦，便于应用配置的修改。当你需要储存机密信息时可以使用 Secret 对象。

备注：ConfigMap 并不提供保密或者加密功能。如果你想存储的数据是机密的，请使用 Secret；或者使用其他第三方工具来保证数据的私密性，而不是用 ConfigMap。

# ConfigMap创建方式 #

## 通过目录创建 ##

配置文件目录

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# ll /root/k8s_practice/storage/configmap # 配置文件存在哪个目录下
    total 8
    -rw-r--r-- 1 root root 159 Jun  7 14:52 game.properties
    -rw-r--r-- 1 root root  83 Jun  7 14:53 ui.properties
    [root@k8s-master storage]#
    [root@k8s-master storage]# cat configmap/game.properties # 涉及文件1
    enemies=aliens
    lives=3
    enemies.cheat=true
    enemies.cheat.level=noGoodRotten
    secret.code.passphrase=UUDDLRLRBABAs
    secret.code.allowed=true
    secret.code.lives=30
    
    [root@k8s-master storage]#
    [root@k8s-master storage]# cat configmap/ui.properties # 涉及文件2
    color.good=purple
    color.bad=yellow
    allow.textmode=true
    how.nice.to.look=fairlyNice

创建ConfigMap并查看状态

[root@k8s-master storage]# kubectl create configmap game-config --from-file=/root/k8s_practice/storage/configmap
    configmap/game-config created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get configmap
    NAME          DATA   AGE
    game-config   2      14s

查看ConfigMap有哪些数据

[root@k8s-master storage]# kubectl get configmap -o yaml ##### 查看方式1
    apiVersion: v1
    items:
    - apiVersion: v1
      data:
        game.properties: |+   ##### 本段最后有一行空格，+ 表示保留字符串行末尾的换行
          enemies=aliens
          lives=3
          enemies.cheat=true
          enemies.cheat.level=noGoodRotten
          secret.code.passphrase=UUDDLRLRBABAs
          secret.code.allowed=true
          secret.code.lives=30
    
        ui.properties: |
          color.good=purple
          color.bad=yellow
          allow.textmode=true
          how.nice.to.look=fairlyNice
      kind: ConfigMap
      metadata:
        creationTimestamp: "2020-06-07T06:57:28Z"
        name: game-config
        namespace: default
        resourceVersion: "889177"
        selfLink: /api/v1/namespaces/default/configmaps/game-config
        uid: 6952ac85-ded0-4c5e-89fd-b0c6f0546ecf
    kind: List
    metadata:
      resourceVersion: ""
      selfLink: ""
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl describe configmap game-config ##### 查看方式2
    Name:         game-config
    Namespace:    default
    Labels:       <none>
    Annotations:  <none>
    
    Data
    ====
    game.properties:
    ----
    enemies=aliens
    lives=3
    enemies.cheat=true
    enemies.cheat.level=noGoodRotten
    secret.code.passphrase=UUDDLRLRBABAs
    secret.code.allowed=true
    secret.code.lives=30
    
    
    ui.properties:
    ----
    color.good=purple
    color.bad=yellow
    allow.textmode=true
    how.nice.to.look=fairlyNice
    
    Events:  <none>

## 通过文件创建 ##

配置文件位置

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# cat /root/k8s_practice/storage/configmap/game.properties
    enemies=aliens
    lives=3
    enemies.cheat=true
    enemies.cheat.level=noGoodRotten
    secret.code.passphrase=UUDDLRLRBABAs
    secret.code.allowed=true
    secret.code.lives=30

创建ConfigMap并查看状态

[root@k8s-master storage]# kubectl create configmap game-config-2 --from-file=/root/k8s_practice/storage/configmap/game.properties
    configmap/game-config-2 created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get configmap game-config-2
    NAME            DATA   AGE
    game-config-2   1      29s

查看ConfigMap有哪些数据

[root@k8s-master storage]# kubectl get configmap game-config-2 -o yaml ##### 查看方式1
    apiVersion: v1
    data:
      game.properties: |+   ##### 本段最后有一行空格，+ 表示保留字符串行末尾的换行
        enemies=aliens
        lives=3
        enemies.cheat=true
        enemies.cheat.level=noGoodRotten
        secret.code.passphrase=UUDDLRLRBABAs
        secret.code.allowed=true
        secret.code.lives=30
    
    kind: ConfigMap
    metadata:
      creationTimestamp: "2020-06-07T07:05:47Z"
      name: game-config-2
      namespace: default
      resourceVersion: "890437"
      selfLink: /api/v1/namespaces/default/configmaps/game-config-2
      uid: 02d99802-c23f-45ad-b4e1-dea9bcb166d8
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl describe configmap game-config-2 ##### 查看方式2
    Name:         game-config-2
    Namespace:    default
    Labels:       <none>
    Annotations:  <none>
    
    Data
    ====
    game.properties:
    ----
    enemies=aliens
    lives=3
    enemies.cheat=true
    enemies.cheat.level=noGoodRotten
    secret.code.passphrase=UUDDLRLRBABAs
    secret.code.allowed=true
    secret.code.lives=30
    
    
    Events:  <none>

## 通过命令行创建 ##

创建ConfigMap并查看状态

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# kubectl create configmap special-config --from-literal=special.how=very --from-literal="special.type=charm"
    configmap/special-config created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get configmap special-config
    NAME             DATA   AGE
    special-config   2      23s

查看ConfigMap有哪些数据

[root@k8s-master storage]# kubectl get configmap special-config -o yaml ##### 查看方式1
    apiVersion: v1
    data:
      special.how: very
      special.type: charm
    kind: ConfigMap
    metadata:
      creationTimestamp: "2020-06-07T09:32:04Z"
      name: special-config
      namespace: default
      resourceVersion: "912702"
      selfLink: /api/v1/namespaces/default/configmaps/special-config
      uid: 76698e78-1380-4826-b5ac-d9c81f746eac
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl describe configmap special-config ##### 查看方式2
    Name:         special-config
    Namespace:    default
    Labels:       <none>
    Annotations:  <none>
    
    Data
    ====
    special.how:
    ----
    very
    special.type:
    ----
    charm
    Events:  <none>

## 通过yaml文件创建 ##

yaml文件

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# cat configmap.yaml
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: configmap-demo
    data:
      # 类属性键；每一个键都映射到一个简单的值
      player_initial_lives: "3"
      ui_properties_file_name: 'user-interface.properties'
      #
      # 类文件键
      game.properties: |
        enemy.types=aliens,monsters
        player.maximum-lives=5
      user-interface.properties: |
        color.good=purple
        color.bad=yellow
        allow.textmode=true

创建ConfigMap并查看状态

[root@k8s-master storage]# kubectl apply -f configmap.yaml
    configmap/configmap-demo created
    [root@k8s-master storage]# kubectl get configmap configmap-demo
    NAME             DATA   AGE
    configmap-demo   4      2m59s

查看ConfigMap有哪些数据

[root@k8s-master storage]# kubectl get configmap configmap-demo -o yaml ##### 查看方式1
    apiVersion: v1
    data:
      game.properties: | enemy.types=aliens,monsters player.maximum-lives=5
      player_initial_lives: "3"
      ui_properties_file_name: user-interface.properties
      user-interface.properties: | color.good=purple color.bad=yellow allow.textmode=true
    kind: ConfigMap
    metadata:
      annotations:
        kubectl.kubernetes.io/last-applied-configuration: | {"apiVersion":"v1","data":{"game.properties":"enemy.types=aliens,monsters\nplayer.maximum-lives=5\n","player_initial_lives":"3","ui_properties_file_name":"user-interface.properties","user-interface.properties":"color.good=purple\ncolor.bad=yellow\nallow.textmode=true\n"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"configmap-demo","namespace":"default"}}
      creationTimestamp: "2020-06-07T11:36:46Z"
      name: configmap-demo
      namespace: default
      resourceVersion: "931685"
      selfLink: /api/v1/namespaces/default/configmaps/configmap-demo
      uid: fdad7000-87bd-4b72-be98-40dd8fe6400a
    [root@k8s-master storage]#
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl describe configmap configmap-demo ##### 查看方式2
    Name:         configmap-demo
    Namespace:    default
    Labels:       <none>
    Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                    { "apiVersion":"v1","data":{ "game.properties":"enemy.types=aliens,monsters\nplayer.maximum-lives=5\n","player_initial_lives":"3","ui_proper...
    
    Data
    ====
    game.properties:
    ----
    enemy.types=aliens,monsters
    player.maximum-lives=5
    
    player_initial_lives:
    ----
    3
    ui_properties_file_name:
    ----
    user-interface.properties
    user-interface.properties:
    ----
    color.good=purple
    color.bad=yellow
    allow.textmode=true
    
    Events:  <none>

# Pod中使用ConfigMap #

如何在Pod中使用上述的ConfigMap信息。

## 当前存在的ConfigMap ##

[root@k8s-master storage]# kubectl get configmap
    NAME             DATA   AGE
    configmap-demo   4      30m
    game-config      2      5h9m
    game-config-2    1      5h1m
    special-config   2      5m48s

## 使用ConfigMap来替代环境变量 ##

yaml文件

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# cat pod_configmap_env.yaml
    apiVersion: v1
    kind: Pod
    metadata:
      name: pod-configmap-env
    spec:
      containers:
      - name: myapp
        image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
        command: ["/bin/sh", "-c", "env"]
        ### 引用方式1
        env:
        - name: SPECAIL_HOW_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config   ### 这个name的值来自 ConfigMap
              key: special.how       ### 这个key的值为需要取值的键
        - name: SPECAIL_TPYE_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.type
        ### 引用方式2
        envFrom:
        - configMapRef:
            name: game-config-2   ### 这个name的值来自 ConfigMap
        restartPolicy: Never

启动pod并查看状态

[root@k8s-master storage]# kubectl apply -f pod_configmap_env.yaml
    pod/pod-configmap-env created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get pod -o wide
    NAME                READY   STATUS      RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
    pod-configmap-env   0/1     Completed   0          6s    10.244.2.147   k8s-node02   <none>           <none>

查看打印日志

[root@k8s-master storage]# kubectl logs pod-configmap-env
    MYAPP_SVC_PORT_80_TCP_ADDR=10.98.57.156
    KUBERNETES_SERVICE_PORT=443
    KUBERNETES_PORT=tcp://10.96.0.1:443
    MYAPP_SVC_PORT_80_TCP_PORT=80
    HOSTNAME=pod-configmap-env
    SHLVL=1
    MYAPP_SVC_PORT_80_TCP_PROTO=tcp
    HOME=/root
    SPECAIL_HOW_KEY=very  ### 来自ConfigMap
    game.properties=enemies=aliens  ### 来自ConfigMap
    lives=3  ### 来自ConfigMap
    enemies.cheat=true  ### 来自ConfigMap
    enemies.cheat.level=noGoodRotten  ### 来自ConfigMap
    secret.code.passphrase=UUDDLRLRBABAs  ### 来自ConfigMap
    secret.code.allowed=true  ### 来自ConfigMap
    secret.code.lives=30  ### 来自ConfigMap
    
    
    SPECAIL_TPYE_KEY=charm  ### 来自ConfigMap
    MYAPP_SVC_PORT_80_TCP=tcp://10.98.57.156:80
    NGINX_VERSION=1.12.2
    KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
    PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
    KUBERNETES_PORT_443_TCP_PORT=443
    KUBERNETES_PORT_443_TCP_PROTO=tcp
    MYAPP_SVC_SERVICE_HOST=10.98.57.156
    KUBERNETES_SERVICE_PORT_HTTPS=443
    KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
    PWD=/
    KUBERNETES_SERVICE_HOST=10.96.0.1
    MYAPP_SVC_SERVICE_PORT=80
    MYAPP_SVC_PORT=tcp://10.98.57.156:80

## 使用ConfigMap设置命令行参数 ##

yaml文件

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# cat pod_configmap_cmd.yaml
    apiVersion: v1
    kind: Pod
    metadata:
      name: pod-configmap-cmd
    spec:
      containers:
      - name: myapp
        image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
        command: ["/bin/sh", "-c", "echo \"===$(SPECAIL_HOW_KEY)===$(SPECAIL_TPYE_KEY)===\""]
        env:
        - name: SPECAIL_HOW_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.how
        - name: SPECAIL_TPYE_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.type
      restartPolicy: Never

启动pod并查看状态

[root@k8s-master storage]# kubectl apply -f pod_configmap_cmd.yaml
    pod/pod-configmap-cmd created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get pod -o wide
    NAME                READY   STATUS      RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
    pod-configmap-cmd   0/1     Completed   0          5s    10.244.4.125   k8s-node01   <none>           <none>

查看打印日志

[root@k8s-master storage]# kubectl logs pod-configmap-cmd
    ===very===charm===

## 通过数据卷插件使用ConfigMap【推荐】 ##

在数据卷里面使用ConfigMap，最基本的就是将文件填入数据卷，在这个文件中，键就是文件名【第一层级的键】，键值就是文件内容。

yaml文件

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# cat pod_configmap_volume.yaml
    apiVersion: v1
    kind: Pod
    metadata:
      name: pod-configmap-volume
    spec:
      containers:
      - name: myapp
        image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
        #command: ["/bin/sh", "-c", "ls -l /etc/config/"]
        command: ["/bin/sh", "-c", "sleep 600"]
        volumeMounts:
        - name: config-volume
          mountPath: /etc/config
      volumes:
      - name: config-volume
        configMap:
          name: configmap-demo
      restartPolicy: Never

启动pod并查看状态

[root@k8s-master storage]# kubectl apply -f pod_configmap_volume.yaml
    pod/pod-configmap-volume created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get pod -o wide
    NAME                   READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
    pod-configmap-volume   1/1     Running   0          5s    10.244.2.153   k8s-node02   <none>           <none>

进入pod并查看

[root@k8s-master storage]# kubectl exec -it pod-configmap-volume sh
    / # ls /etc/config
    game.properties            player_initial_lives       ui_properties_file_name    user-interface.properties
    / #
    / #
    / #
    / # cat /etc/config/player_initial_lives
    3/ #
    / #
    / #
    / # cat /etc/config/ui_properties_file_name
    user-interface.properties/ #
    / #
    / #
    / # cat /etc/config/game.properties
    enemy.types=aliens,monsters
    player.maximum-lives=5
    / #
    / #
    / # cat /etc/config/user-interface.properties
    color.good=purple
    color.bad=yellow
    allow.textmode=true

# ConfigMap热更新 #

## 准备工作 ##

yaml文件

[root@k8s-master storage]# pwd
    /root/k8s_practice/storage
    [root@k8s-master storage]# cat pod_configmap_hot.yaml
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: log-config
      namespace: default
    data:
      log_level: INFO
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: myapp-deploy
      namespace: default
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: myapp
          release: v1
      template:
        metadata:
          labels:
            app: myapp
            release: v1
            env: test
        spec:
          containers:
          - name: myapp
            image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
            imagePullPolicy: IfNotPresent
            ports:
            - containerPort: 80
            volumeMounts:
            - name: config-volume
              mountPath: /etc/config
          volumes:
          - name: config-volume
            configMap:
              name: log-config

应用yaml文件并查看状态

[root@k8s-master storage]# kubectl apply -f pod_configmap_hot.yaml
    configmap/log-config created
    deployment.apps/myapp-deploy created
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get configmap log-config
    NAME         DATA   AGE
    log-config   1      21s
    [root@k8s-master storage]#
    [root@k8s-master storage]# kubectl get pod -o wide
    NAME                           READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
    myapp-deploy-58ff9c997-drhwk   1/1     Running   0          30s   10.244.2.154   k8s-node02   <none>           <none>
    myapp-deploy-58ff9c997-n68j2   1/1     Running   0          30s   10.244.4.126   k8s-node01   <none>           <none>

查看ConfigMap信息

[root@k8s-master storage]# kubectl get configmap log-config -o yaml
    apiVersion: v1
    data:
      log_level: INFO
    kind: ConfigMap
    metadata:
      annotations:
        kubectl.kubernetes.io/last-applied-configuration: | {"apiVersion":"v1","data":{"log_level":"INFO"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"log-config","namespace":"default"}}
      creationTimestamp: "2020-06-07T16:08:11Z"
      name: log-config
      namespace: default
      resourceVersion: "971348"
      selfLink: /api/v1/namespaces/default/configmaps/log-config
      uid: 7e78e1d7-12de-4601-9915-cefbc96ca305

查看pod中的ConfigMap信息

[root@k8s-master storage]# kubectl exec -it myapp-deploy-58ff9c997-drhwk -- cat /etc/config/log_level
    INFO

## 热更新 ##

修改ConfigMap

[root@k8s-master storage]# kubectl edit configmap log-config ### 将 INFO 改为了 DEBUG
    # Please edit the object below. Lines beginning with a '#' will be ignored,
    # and an empty file will abort the edit. If an error occurs while saving this file will be
    # reopened with the relevant failures.
    #
    apiVersion: v1
    data:
      log_level: DEBUG
    kind: ConfigMap
    metadata:
      annotations:
        kubectl.kubernetes.io/last-applied-configuration: |
          { "apiVersion":"v1","data":{ "log_level":"DEBUG"},"kind":"ConfigMap","metadata":{ "annotations":{ },"name":"log-config","namespace":"default"}}
      creationTimestamp: "2020-06-07T16:08:11Z"
      name: log-config
      namespace: default
      resourceVersion: "971348"
      selfLink: /api/v1/namespaces/default/configmaps/log-config
      uid: 7e78e1d7-12de-4601-9915-cefbc96ca305

查看ConfigMap信息

[root@k8s-master storage]# kubectl get configmap log-config -o yaml
    apiVersion: v1
    data:
      log_level: DEBUG
    kind: ConfigMap
    metadata:
      annotations:
        kubectl.kubernetes.io/last-applied-configuration: | {"apiVersion":"v1","data":{"log_level":"DEBUG"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"log-config","namespace":"default"}}
      creationTimestamp: "2020-06-07T16:08:11Z"
      name: log-config
      namespace: default
      resourceVersion: "972893"
      selfLink: /api/v1/namespaces/default/configmaps/log-config
      uid: 7e78e1d7-12de-4601-9915-cefbc96ca305

稍后10秒左右，再次查看pod中的ConfigMap信息

[root@k8s-master storage]# kubectl exec -it myapp-deploy-58ff9c997-drhwk -- cat /etc/config/log_level
    DEBUG

由此可见，完成了一次热更新

[Kubernetes K8S_ConfigMap]: https://www.cnblogs.com/zhanglianghhh/p/13818190.html