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helm-入门学习笔记

hmtk123 2021-05-17 17:02 原文

一、概述

1.1、什么是helm

helm之前部署一般使用编写yaml文件方式进行应用部署。这种方式比较适用于部署单一类型应用。在服务较多的情况下，为每个服务维护一个yaml文件，就会变得比较繁琐和臃肿，而且容易出错。使用helm可以把这些yaml作为一个整体进行管理，并且实现应用版本管理

helm致力于帮助您管理kubernetes应用，helm charts可以帮助你定义、安装、和升级比较复杂的应用：
helm可以做如下内容：

  • Create new charts from scratch
  • Package charts into chart archive (tgz) files
  • Interact with chart repositories where charts are stored
  • Install and uninstall charts into an existing Kubernetes cluster
  • Manage the release cycle of charts that have been installed with Helm

1.2、概念

  1. The chart is a bundle of information necessary to create an instance of a Kubernetes application.

  2. The config contains configuration information that can be merged into a packaged chart to create a releasable object.

  3. A release is a running instance of a chart, combined with a specific config.

  • Helm 是一个命令行下的客户端工具。主要用于 Kubernetes 应用程序 Chart 的创建、打包、发布以及创建和管理本地和远程的 Chart 仓库。

  • Tiller 是 Helm 的服务端，部署在 Kubernetes 集群中。Tiller 用于接收 Helm 的请求，并根据 Chart 生成 Kubernetes 的部署文件（ Helm 称为 Release ），然后提交给 Kubernetes 创建应用。Tiller 还提供了 Release 的升级、删除、回滚等一系列功能。在V3版本中已经删除。去掉后通过kubeconfig直接连接apiserver

  • Chart Helm 的软件包，采用 TAR 格式。类似于 APT 的 DEB 包或者 YUM 的 RPM 包，其包含了一组定义 Kubernetes 资源相关的 YAML 文件

  • Repoistory Helm 的软件仓库，Repository 本质上是一个 Web 服务器，该服务器保存了一系列的 Chart 软件包以供用户下载，并且提供了一个该 Repository 的 Chart 包的清单文件以供查询。Helm 可以同时管理多个不同的 Repository。

  • Release：基于chart的部署实体，一个chart被helm运行后将会生成对应的一个release；将在k8s中创建出真实运行的资源对象。在v3版本中支持不同namespace中重用

注意：这个Tiller是在远程调用的时候才会用到，如果kubectl终端和helm安装都在一台机器上，不用安装Tiller也可以的。也可以手动指定--kube-apiserver,--kube-context,--kubeconfig。可以把helm理解为yum/apt等包管理工具，方便的把yaml文件部署到k8s集群中

1.3、安装

安装前提：

  • 已经有一个kubernetes集群
  • 本地具有一个kubectl

Helm和kubernetes版本的对应关系：https://helm.sh/docs/topics/version_skew/ ，这里选择 v3.2.2

下载地址：https://github.com/helm/helm/releases

[root@master1 helm]# wget https://get.helm.sh/helm-v3.5.4-linux-amd64.tar.gz
[root@master1 helm]# tar xvf helm-v3.5.4-linux-amd64.tar.gz
[root@master1 helm]# cp linux-amd64/helm /usr/bin/

1.4、使用方法

#1、仓库操作
helm repo add $仓库名称  $仓库地址 

[root@master1 ~]# helm repo add azure http://mirror.azure.cn/kubernetes/charts
"azure" has been added to your repositories
[root@master1 ~]# helm repo add aliyun https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
"aliyun" has been added to your repositories
[root@master1 ~]# helm repo list
NAME    URL
azure   http://mirror.azure.cn/kubernetes/charts
aliyun  https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts

helm repo add|remove|update|list

#2、helm快速部署应用
[root@master1 ~]# helm search repo weave  #查找charts
NAME                    CHART VERSION   APP VERSION     DESCRIPTION
aliyun/weave-cloud      0.1.2                           Weave Cloud is a add-on to Kubernetes which pro...
aliyun/weave-scope      0.9.2           1.6.5           A Helm chart for the Weave Scope cluster visual...
azure/weave-cloud       0.3.9           1.4.0           DEPRECATED - Weave Cloud is a add-on to Kuberne...
azure/weave-scope       1.1.12          1.12.0          DEPRECATED - A Helm chart for the Weave Scope c...
[root@master1 ~]# helm install helm-ui azure/weave-scope  #安装
WARNING: This chart is deprecated
NAME: helm-ui
LAST DEPLOYED: Tue May 11 21:01:39 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
You should now be able to access the Scope frontend in your web browser, by
using kubectl port-forward:

kubectl -n default port-forward $(kubectl -n default get endpoints \
helm-ui-weave-scope -o jsonpath='{.subsets[0].addresses[0].targetRef.name}') 8080:4040

then browsing to http://localhost:8080/.
For more details on using Weave Scope, see the Weave Scope documentation:

https://www.weave.works/docs/scope/latest/introducing/

[root@master1 ~]# helm list  #查看
NAME    NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
helm-ui default         1               2021-05-11 21:01:39.640749808 +0800 CST deployed        weave-scope-1.1.12      1.12.0
[root@master1 ~]# helm status helm-ui  #查看
NAME: helm-ui
LAST DEPLOYED: Tue May 11 21:01:39 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
You should now be able to access the Scope frontend in your web browser, by
using kubectl port-forward:

kubectl -n default port-forward $(kubectl -n default get endpoints \
helm-ui-weave-scope -o jsonpath='{.subsets[0].addresses[0].targetRef.name}') 8080:4040

then browsing to http://localhost:8080/.
For more details on using Weave Scope, see the Weave Scope documentation:

https://www.weave.works/docs/scope/latest/introducing/
[root@master1 ~]# kubectl  get pods
NAME                                                 READY   STATUS    RESTARTS   AGE
weave-scope-agent-helm-ui-9z8n4                      1/1     Running   0          5m37s
weave-scope-agent-helm-ui-cw5x4                      1/1     Running   0          5m37s
weave-scope-agent-helm-ui-zqh4k                      1/1     Running   0          5m37s
weave-scope-cluster-agent-helm-ui-5b8584f786-lvmlm   1/1     Running   0          5m37s
weave-scope-frontend-helm-ui-ffc59db79-dnxqk         1/1     Running   0          5m37s
[root@master1 ~]# kubectl  get svc
NAME                  TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
helm-ui-weave-scope   ClusterIP   10.104.224.57   <none>        80/TCP    5m40s
kubernetes            ClusterIP   10.96.0.1       <none>        443/TCP   3d4h
[root@master1 ~]# kubectl  expose deployment/weave-scope-frontend-helm-ui --port=4040 --type=NodePort --name=weave-nodeport
[root@master1 ~]# kubectl  get svc
NAME                  TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
helm-ui-weave-scope   NodePort    10.104.224.57   <none>        80:30019/TCP   10m
kubernetes            ClusterIP   10.96.0.1       <none>        443/TCP        3d4h
通过集群任意一个节点 :30019就可以访问helm的ui界面

1.5、helm配置文件

1.5、helm配置文件

Operating System Cache Path Configuration Path Data Path
Linux $HOME/.cache/helm $HOME/.config/helm $HOME/.local/share/helm
macOS $HOME/Library/Caches/helm $HOME/Library/Preferences/helm $HOME/Library/helm
Windows %TEMP%\helm %APPDATA%\helm %APPDATA%\helm 
[root@master1 ~]# cat .config/helm/repositories.yaml
apiVersion: ""
generated: "0001-01-01T00:00:00Z"
repositories:
- caFile: ""
  certFile: ""
  insecure_skip_tls_verify: false
  keyFile: ""
  name: azure
  password: ""
  url: http://mirror.azure.cn/kubernetes/charts
  username: ""
- caFile: ""
  certFile: ""
  insecure_skip_tls_verify: false
  keyFile: ""
  name: aliyun
  password: ""
  url: https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
  username: ""
[root@master1 ~]# ls -l  .cache/helm/repository/
总用量 9960
-rw-r--r-- 1 root root    1400 5月  11 21:01 aliyun-charts.txt
-rw-r--r-- 1 root root  296570 5月  11 21:01 aliyun-index.yaml
-rw-r--r-- 1 root root    3370 5月  11 21:01 azure-charts.txt
-rw-r--r-- 1 root root 9874153 5月  11 21:01 azure-index.yaml
-rw-r--r-- 1 root root    7269 5月  11 21:01 weave-scope-1.1.12.tgz

二、chart简单使用

2.1、自定义chart说明

[root@master1 ~]# helm create mychart
[root@master1 ~]# find  mychart/*
mychart/charts		#该目录中放置当前Chart依赖的其它Chart
mychart/Chart.yaml	#配置当前chart的一些属性信息
mychart/templates	#存放yaml文件
mychart/templates/ingress.yaml	
mychart/templates/deployment.yaml
mychart/templates/service.yaml
mychart/templates/serviceaccount.yaml
mychart/templates/hpa.yaml
mychart/templates/NOTES.txt
mychart/templates/_helpers.tpl
mychart/templates/tests
mychart/templates/tests/test-connection.yaml
mychart/values.yaml	#全局的变量，在template中可以引用
requirements.yaml   # [可选] 用于存放当前Chart依赖的其它Chart的说明文件

2.2、创建yaml文件

在template中创建yaml文件

[root@master1 ~]# cd mychart/templates/
[root@master1 templates]# kubectl create deployment web1 --image=nginx --dry-run -o yaml > deployment.yaml
[root@master1 templates]# kubectl apply -f deployment.yaml
deployment.apps/web1 created
[root@master1 templates]# kubectl expose deployment web1 --port=80 --target-port=80 --type=NodePort --dry-run -o yaml > service.yaml
[root@master1 templates]# kubectl delete -f deployment.yaml
[root@master1 templates]# ll
总用量 8
-rw-r--r-- 1 root root 380 5月  12 14:52 deployment.yaml
-rw-r--r-- 1 root root 237 5月  12 14:56 service.yaml

2.3、自定义charts安装

# 1、安装自定义chart 
[root@master1 ~]# helm install web1 mychart/
NAME: web1
LAST DEPLOYED: Wed May 12 14:59:22 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
[root@master1 ~]# kubectl  get svc web1
NAME   TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
web1   NodePort   10.106.41.251   <none>        80:30826/TCP   28s
[root@master1 ~]# kubectl  get pods |grep web1
web1-7f87dfbd56-2q8nf                                1/1     Running   0          39s

# 2、自定义chart升级
[root@master1 ~]# helm upgrade web1 mychart/
Release "web1" has been upgraded. Happy Helming!
NAME: web1
LAST DEPLOYED: Wed May 12 15:02:34 2021
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE: None

2.4、参数传递

在values.yaml中定义变量和值，在具体yaml文件中，获取定义的值，引用方式：变量引用方式：{{ .Values.变量名称 }}

[root@master1 ~]# cat mychart/values.yaml
replicaCount: 1
image:
  repository: nginx
  tag: 1.16
label: nginx
port: 80


[root@master1 ~]# cat mychart/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: web1
  name: {{ .Release.Name }}-deploy
spec:
  replicas: 1
  selector:
    matchLabels:
      app: {{ .Values.label }}
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: {{ .Values.label }}
    spec:
      containers:
      - image: {{ .Values.image.repository }}
        name: nginx
        resources: {}
status: {}
	

[root@master1 ~]# cat mychart/templates/service.yaml
apiVersion: v1
kind: Service
metadata:
  name: {{ .Release.Name }}-svc
spec:
  ports:
  - port: {{ .Values.port }}
    protocol: TCP
    targetPort: 80
  selector:
    app: {{ .Values.label }}
  type: NodePort
status:
  loadBalancer: {}

[root@master1 ~]# helm install web2 ./mychart --dry-run
[root@master1 ~]# helm install web2 ./mychart
NAME: web2
LAST DEPLOYED: Wed May 12 15:46:42 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None

$ helm install --set image=redis --set tag=5.0.5-alpine stable/redis-ha  #可以使用--set 修改单个value
$ helm install -f values.yaml  #可以使用-f指定values.yaml

2.5、建立本地repo

1、安装chartmusem,默认存储为本地文件系统
[root@master1 helm]# wget https://github.com/helm/charts/archive/refs/heads/master.zip
[root@master1 charts-master]# helm install  chartmusem stable/chartmuseum/ 

2、安装push插件
安装方法1：
[root@master1 charts-master]# helm plugin install  https://github.com/chartmuseum/helm-push.git 

[root@master1 ~]# helm plugin install  https://github.com/chartmuseum/helm-push.git 
Error: Unable to update repository: exit status 1
清理cache缓存
[root@master1 .cache]# rm -rf "$(helm env HELM_CACHE_HOME)"

安装方法2：(推荐)
[root@master1 push]# wget https://github.com/chartmuseum/helm-push/releases/download/v0.9.0/helm-push_0.9.0_darwin_amd64.tar.gz 
[root@master1 push]# mkdir $(helm env HELM_PLUGINS)/helm-push 
[root@master1 push]# tar xvf helm-push_0.9.0_linux_amd64.tar.gz -C $(helm env HELM_PLUGINS)/helm-push
LICENSE
plugin.yaml
bin/helmpush
[root@master1 ~]# helm plugin list
NAME	VERSION	DESCRIPTION                      
push	0.9.0  	Push chart package to ChartMuseum
[root@master1 mychart]# helm repo add myrepo http://10.106.36.233:8080
"myrepo" has been added to your repositories
[root@master1 mychart]# helm repo list
NAME  	URL                                                   
azure 	http://mirror.azure.cn/kubernetes/charts              
aliyun	https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
myrepo	http://10.106.36.233:8080  
[root@master1 ~]# helm push --force  mychart/mychart-0.1.0.tgz myrepo  #报错
Pushing mychart-0.1.0.tgz to myrepo...
Error: 404: not found

暂未解决。待后续解决后记录

三、附件

[root@master1 weave-scope]# find ./*
./charts
./charts/weave-scope-frontend
./charts/weave-scope-frontend/Chart.yaml
./charts/weave-scope-frontend/templates
./charts/weave-scope-frontend/templates/_helpers.tpl
./charts/weave-scope-frontend/templates/deployment.yaml		#见附件
./charts/weave-scope-frontend/templates/ingress.yaml		#见附件
./charts/weave-scope-frontend/templates/service.yaml		#见附件
./charts/weave-scope-agent
./charts/weave-scope-agent/Chart.yaml		
./charts/weave-scope-agent/templates
./charts/weave-scope-agent/templates/_helpers.tpl
./charts/weave-scope-agent/templates/daemonset.yaml			#见附件
./charts/weave-scope-cluster-agent
./charts/weave-scope-cluster-agent/Chart.yaml
./charts/weave-scope-cluster-agent/templates
./charts/weave-scope-cluster-agent/templates/_helpers.tpl
./charts/weave-scope-cluster-agent/templates/clusterrole.yaml	#见附件
./charts/weave-scope-cluster-agent/templates/clusterrolebinding.yaml	#见附件
./charts/weave-scope-cluster-agent/templates/deployment.yaml		#见附件
./charts/weave-scope-cluster-agent/templates/serviceaccount.yaml		#见附件
./Chart.yaml
./README.md
./templates
./templates/NOTES.txt
./templates/_helpers.tpl
./templates/test-config.yaml
./templates/weave-scope-tests.yaml
./values.yaml		#见附件

3.1、values.yaml

[root@master1 weave-scope]# cat values.yaml  |grep -v "#"
global:
  image:
    repository: weaveworks/scope
    tag: 1.12.0
    pullPolicy: "IfNotPresent"
  service:
    port: 80
    type: "ClusterIP"

weave-scope-frontend:
  enabled: true
  flags: []
  ingress:
    enabled: false
    annotations: {}
    paths: []
    hosts:
      - weave-scope.example.test
    tls: []

weave-scope-agent:
  enabled: true
  flags: []
  dockerBridge: "docker0"
  scopeFrontendAddr: ""
  probeToken: ""
  readOnly: false

weave-scope-cluster-agent:
  enabled: true
  flags: []
  scopeFrontendAddr: ""
  probeToken: ""
  rbac:
    create: true
  readOnly: false
  serviceAccount:
    create: true

3.2、weave-scope-frontend

[root@master1 templates]# cat deployment.yaml
{{- if .Values.enabled -}}  #嵌套最外层，enable才继续
apiVersion: {{ template "deployment.apiVersion" . }}
kind: Deployment
metadata:
  labels:
    {{- include "weave-scope-frontend.helm_std_labels" . | indent 4 }}
    component: frontend
  name: {{ template "weave-scope-frontend.fullname" . }}
  annotations:
    {{- include "weave-scope.annotations" . | indent 4 }}
spec:
  replicas: 1
  selector:
    matchLabels:
      app: {{ template "toplevel.name" . }}
      release: {{ .Release.Name }}  #内置的函数
      component: frontend
  template:
    metadata:
      labels:
        {{- include "weave-scope-frontend.helm_std_labels" . | indent 8 }}
        component: frontend
    spec:
      containers:
        - name: {{ template "weave-scope-frontend.name" . }}
          image: "{{ .Values.global.image.repository }}:{{ .Values.global.image.tag }}"  #从values.yaml文件中提取
          imagePullPolicy: "{{ .Values.global.image.pullPolicy }}" #从yaml文件中提取
          args:
            - "--no-probe"
            {{- range $arg := .Values.flags }}
            - {{ $arg | quote }}
            {{- end }}
          ports:
            - name: http
              containerPort: 4040
              protocol: TCP
          resources:
{{ toYaml .Values.resources | indent 12 }}
{{- end -}}


[root@master1 templates]# cat service.yaml
{{- if .Values.enabled -}}
apiVersion: v1
kind: Service
metadata:
  labels:
    {{- include "weave-scope-frontend.helm_std_labels" . | indent 4 }}
    component: frontend
  name: {{ .Values.global.service.name | default (include "toplevel.fullname" .) }}
  annotations:
    {{- include "weave-scope-frontend.annotations" . | indent 4 }}
spec:
  ports:
    - name: http
      port: {{ .Values.global.service.port }}
      targetPort: http
      protocol: TCP
  selector:
    app: {{ template "toplevel.name" . }}
    release: {{ .Release.Name }}
    component: frontend
  type: {{ .Values.global.service.type }}
{{- end -}}


[root@master1 templates]# cat ingress.yaml
{{- if .Values.ingress.enabled -}}
{{- $fullName := .Values.global.service.name | default (include "toplevel.fullname" .) -}}
{{- $ingressPaths := .Values.ingress.paths -}}
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  labels:
    {{- include "weave-scope-frontend.helm_std_labels" . | indent 4 }}
    component: frontend
  name: {{ template "weave-scope-frontend.fullname" . }}
  annotations:
    {{- include "weave-scope.annotations" . | indent 4 }}
    {{- with .Values.ingress.annotations }}
    {{- toYaml . | nindent 4 }}
    {{- end }}
spec:
{{- if .Values.ingress.tls }}
  tls:
  {{- range .Values.ingress.tls }}
    - hosts:
      {{- range .hosts }}
        - {{ . | quote }}
      {{- end }}
      secretName: {{ .secretName }}
  {{- end }}
{{- end }}
  rules:
  {{- range .Values.ingress.hosts }}
    - host: {{ . | quote }}
      http:
        paths:
    {{- range $ingressPaths }}
          - path: {{ . }}
            backend:
              serviceName: {{ $fullName }}
              servicePort: http
    {{- end }}
  {{- end }}
{{- end }}
[root@master1 templates]#

3.3、weave-scope-agent

[root@master1 charts]# cat weave-scope-agent/templates/daemonset.yaml
{{- if .Values.enabled -}}
apiVersion: {{ template "daemonset.apiVersion" . }}
kind: DaemonSet
metadata:
  labels:
    {{- include "weave-scope-agent.helm_std_labels" . | indent 4 }}
    component: agent
  name: {{ template "weave-scope-agent.fullname" . }}
  annotations:
    {{- include "weave-scope-agent.annotations" . | indent 4 }}
spec:
  selector:
    matchLabels:
      app: {{ template "toplevel.name" . }}
      release: {{ .Release.Name }}
      component: agent
  updateStrategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        {{- include "weave-scope-agent.helm_std_labels" . | indent 8 }}
        component: agent
    spec:
      tolerations:
        - effect: NoSchedule
          operator: Exists
      {{- if .Values.priorityClassName }}
      priorityClassName: {{ .Values.priorityClassName }}
      {{- end }}
      containers:
        - name: {{ template "weave-scope-agent.name" . }}
          image: "{{ .Values.global.image.repository }}:{{ .Values.global.image.tag }}"
          imagePullPolicy: "{{ .Values.global.image.pullPolicy }}"
          args:
            - '--mode=probe'
            - '--probe-only'
            - '--probe.kubernetes.role=host'
            - '--probe.docker.bridge={{ .Values.dockerBridge }}'
            - '--probe.docker=true'
            - '--probe.kubernetes=true'
            {{- range $arg := .Values.flags }}
            - {{ $arg | quote }}
            {{- end }}
            {{if .Values.readOnly}}
            - "--probe.no-controls"
            {{end}}
            {{- if .Values.global.probeToken }}
            - '--probe-token={{ .Values.global.probeToken }}'
            {{- else if .Values.global.scopeFrontendAddr }}
            - {{ .Values.global.scopeFrontendAddr }}
            {{- else }}
            - {{ .Values.global.service.name | default (include "toplevel.fullname" .) }}.{{ .Release.Namespace }}.svc:{{ .Values.global.service.port }}
            {{- end }}
          securityContext:
            privileged: true
          resources:
{{ toYaml .Values.resources | indent 12 }}
          volumeMounts:
            - name: docker-socket
              mountPath: /var/run/docker.sock
            - name: scope-plugins
              mountPath: /var/run/scope/plugins
            - name: sys-kernel-debug
              mountPath: /sys/kernel/debug
      volumes:
        - name: docker-socket
          hostPath:
            path: /var/run/docker.sock
        - name: scope-plugins
          hostPath:
            path: /var/run/scope/plugins
        - name: sys-kernel-debug
          hostPath:
            path: /sys/kernel/debug
      hostPID: true
      hostNetwork: true
      dnsPolicy: ClusterFirstWithHostNet
{{- end -}}

3.4、weave-scope-cluster-agent

[root@master1 charts]# cat weave-scope-cluster-agent/templates/clusterrolebinding.yaml
{{- if .Values.enabled -}}
{{- if .Values.rbac.create }}
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  labels:
    {{- include "weave-scope.helm_std_labels" . | indent 4 }}
    component: agent
  name: {{ include "toplevel.fullname" . }}
  annotations:
    {{- include "weave-scope.annotations" . | indent 4 }}
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: {{ template "weave-scope-agent.serviceAccountName" . }}
subjects:
  - kind: ServiceAccount
    name: {{ template "weave-scope-agent.serviceAccountName" . }}
    namespace: {{ .Release.Namespace }}
{{- end }}
{{- end -}}


[root@master1 charts]# cat weave-scope-cluster-agent/templates/clusterrole.yaml
{{- if .Values.enabled -}}
{{- if .Values.rbac.create }}
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  labels:
    {{- include "weave-scope.helm_std_labels" . | indent 4 }}
    component: agent
  name: {{ template "weave-scope-agent.serviceAccountName" . }}
  annotations:
    {{- include "weave-scope.annotations" . | indent 4 }}
rules:
  - apiGroups:
      - '*'
    resources:
      - '*'
    verbs:
      - '*'
  - nonResourceURLs:
      - '*'
    verbs:
      - '*'
{{- end }}
{{- end -}}


[root@master1 charts]# cat weave-scope-cluster-agent/templates/deployment.yaml
{{- if .Values.enabled -}}
apiVersion: {{ template "deployment.apiVersion" . }}
kind: Deployment
metadata:
  labels:
    {{- include "weave-scope-cluster-agent.helm_std_labels" . | indent 4 }}
    component: cluster-agent
  name: {{ template "weave-scope-cluster-agent.fullname" . }}
  annotations:
    {{- include "weave-scope-cluster-agent.annotations" . | indent 4 }}
spec:
  selector:
    matchLabels:
      app: {{ template "toplevel.name" . }}
      release: {{ .Release.Name }}
      component: cluster-agent
  strategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        {{- include "weave-scope-cluster-agent.helm_std_labels" . | indent 8 }}
        component: cluster-agent
    spec:
      containers:
        - name: {{ template "weave-scope-cluster-agent.name" . }}
          image: "{{ .Values.global.image.repository }}:{{ .Values.global.image.tag }}"
          imagePullPolicy: "{{ .Values.global.image.pullPolicy }}"
          args:
            - '--mode=probe'
            - '--probe-only'
            - '--probe.kubernetes.role=cluster'
            {{- range $arg := .Values.flags }}
            - {{ $arg | quote }}
            {{- end }}
            {{if .Values.readOnly}}
            - "--probe.no-controls"
            {{end}}
            {{- if .Values.global.scopeFrontendAddr }}
            - {{ .Values.global.scopeFrontendAddr }}
            {{- else }}
            - {{ .Values.global.service.name | default (include "toplevel.fullname" .) }}.{{ .Release.Namespace }}.svc:{{ .Values.global.service.port }}
            {{- end }}
          resources:
{{ toYaml .Values.resources | indent 12 }}
      serviceAccountName: {{ template "weave-scope-cluster-agent.serviceAccountName" . }}
{{- end -}}


[root@master1 charts]# cat weave-scope-cluster-agent/templates/serviceaccount.yaml
{{- if .Values.enabled -}}
{{- if .Values.serviceAccount.create }}
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    {{- include "weave-scope.helm_std_labels" . | indent 4 }}
    component: agent
  name: {{ template "weave-scope-agent.serviceAccountName" . }}
  annotations:
    {{- include "weave-scope.annotations" . | indent 4 }}
{{- end }}
{{- end -}}

四、chart进阶

1、约定：

  • chart名称中不能用大写字母也不能用下划线。点 . 符号也不行。
  • YAML 文件应该按照 双空格 缩进(绝不要使用tab键)。
  • values.yaml: 自定义变量名称以小写字母开头，单词按驼峰区分
  • 所有的Helm内置变量以大写字母开头，以便与用户定义的value进行区：.Release.Name，.Capabilities.KubeVersion

2、数据类型：

foo: false 和 foo: "false" 是不一样的
通常，为了避免整数转换问题，将整型存储为字符串更好，并用 {{ int $value }} 在模板中将字符串转回整型。

3、三种类型的value来源：

  • chart的values.yaml文件
  • 由helm install -f 或 helm upgrade -f提供的values文件
  • 在执行helm install 或 helm upgrade 时传递给--set 或 --set-string 参数的values

4、templates结构：

templates/目录结构应该如下：

  • 如果生成YAML输出，模板文件应该有扩展名.yaml。 扩展名是.tpl可用于生成非格式化内容的模板文件。
  • 模板文件名称应该使用横杠符号(my-example-configmap.yaml)，不用驼峰记法。
  • 每个资源的定义应该在它自己的模板文件中。
  • 模板文件的名称应该反映名称中的资源类型。比如：foo-pod.yaml， bar-svc.yaml
  • 定义的模板(在{{ define }}命令中定义的模板)是可全局访问的。这就意味着chart和所有的子chart都可以访问用{{ define }}创建的所有模板。

5、其他

  • 其他用法，见官网：https://helm.sh/docs/chart_template_guide/getting_started/
  • 内置的对象: https://helm.sh/docs/chart_template_guide/builtin_objects/
  • 模板支持的函数：https://helm.sh/zh/docs/chart_template_guide/function_list/
  • 项目地址：https://github.com/helm/charts/tree/master/stable/chartmuseum

备注：helm部分未作深入理解，有实际需求再进行深入理解。

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