kubernets：Helm小练手

冷不防 2023-06-12 11:19 16阅读 0赞

#### 简述 ####

helm是k8s的包管理工具，类似于我们手机上的华为市场或者小米的应用商店。他提供了包的查找，安装，卸载，状态查看一条龙的服务。最近学了一下，自己想了个例子，练练手

#### 例子涵盖的技能点 ####

*  从文件中读取内容
 *  Hook
 *  变量的定义，使用
 *  NOTES.txt
 *  流程控制操作符的应用

#### 开始操练起来 ####

*  创建一个chart

helm create nginx-base-package

*  删除多余的文件

rm -rf  templates/*

*  编写变量文件values.yaml

deploymentLabel:
       app: nginx
       type: middleware
       environment: test
    
    deploymentSpec:
       replicas: !!int "1"
       
    deploymentTemplate:
       image: nginx
       ports:
         containerPort: !!int "80"
       env:
         shell: bash
         author: hananmin

*  创建两个文件用于存储configmap

#deployment-configmap-02.toml
    action = "The config of deployment 02"

#deployment-configmap.toml
    action = "The config of deployment"
    remark = "The remark of deployment"

*  创建configmap的模板

#templates/configmap.yaml 
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: {
       { .Release.Name }}-{
       { .Release.Revision }}-configmap
    data:
      {
       {- $file := .Files }}
      {
       {- range list "deployment-configmap.toml"}}
      {
       { . }}: |-
         {
       {  $file.Get .|quote }}
      {
       {- end }}
      {
       {- (.Files.Glob "deployment-configmap-02.toml").AsConfig | nindent 2 }}

*  创建deployment的模板

#templates/deployment.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: {
       { .Release.Name }}-{
       { .Release.Revision }}-deployment
      labels:
        {
       {- range $key, $val :=  .Values.deploymentLabel }}
           {
       { $key }}: {
       { $val | quote }}
        {
       {- end}}
    spec:
      replicas: {
       { .Values.deploymentSpec.replicas }}
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
           - name: nginx
             image: nginx:1.7.9
             env:
               {
       {- range $key, $val :=  .Values.deploymentLabel }}
                  - name: {
       { $key }}
                    value: {
       { $val | title|quote }}
               {
       {- end}}
             ports:
               - containerPort: {
       { .Values.deploymentTemplate.ports.containerPort }}
             volumeMounts:
               - name: config-volume
                 mountPath: /tmp/config
          volumes:
           - name: config-volume
             configMap:
               name: {
       { .Release.Name }}-{
       { .Release.Revision }}-configmap

*  创建Hook的模板

#templates/pre-install.yaml
    apiVersion: batch/v1
    kind: Job
    metadata:
      name: "{
       { .Release.Name }}"
      labels:
        helm.sh/chart: "{
       { .Release.Name }}-{
       { .Chart.Version }}"
      annotations:
        # This is what defines this resource as a hook. Without this line, the
        # job is considered part of the release.
        "helm.sh/hook": pre-install
        "helm.sh/hook-weight": "5"
        "helm.sh/hook-delete-policy": before-hook-creation  
    spec:
      template:
        metadata:
          name: "{
       { .Release.Name }}"
          helm.sh/chart: "{
       { .Release.Name }}-{
       { .Chart.Version }}"
        spec:
          restartPolicy: Never
          containers:
          - name: pre-install-job
            image: "busybox:latest"
            command: ["echo","I am pre-install Job,time:","`date`"]

*  创建NOTE.TXT

# templates/NOTES.txt
    Thank you for installing {
       { .Chart.Name }}.
    
    Your release is named {
       { .Release.Name }}.
    
    To learn more about the release, try:
    
      $ helm status {
       { .Release.Name }}
      $ helm get {
       { .Release.Name }}

*  检查一下

helm install --dry-run --debug

运行完命令你会看到，给k8s的MANIFEST，如果输出中没有报错，可以进行下面的操作

*  安装

helm install nginx-base-package/

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ2ODYzOTk_size_16_color_FFFFFF_t_70]  
helm install命令不会等待所有的pod都启动，后续查看release的状态，需要用到helm status

#### 在k8s层面检查一下 ####

*  首先，我们的pre-install启动了一个job  
    ![在这里插入图片描述][20191112190818328.png]
 *  其次，应该有一副本的deployment启动  
    ![在这里插入图片描述][20191112190750924.png]
 *  因为deployment是一副本，所以应该有一个pod启动  
    ![在这里插入图片描述][20191112190926643.png]

--------------------

> 先写的这里了，如果有问题或者异议，请进QQ群630300475，大家聊聊

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ2ODYzOTk_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/2019111219042395.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ2ODYzOTk=,size_16,color_FFFFFF,t_70
[20191112190818328.png]: https://img-blog.csdnimg.cn/20191112190818328.png
[20191112190750924.png]: https://img-blog.csdnimg.cn/20191112190750924.png
[20191112190926643.png]: https://img-blog.csdnimg.cn/20191112190926643.png