Helm chart 实践

helm create five_minute_learn

-> % tree -a five_minute_learn
five_minute_learn
├── .helmignore
├── Chart.yaml
├── charts
├── templates
│   ├── NOTES.txt
│   ├── _helpers.tpl
│   ├── deployment.yaml
│   ├── hpa.yaml
│   ├── ingress.yaml
│   ├── service.yaml
│   ├── serviceaccount.yaml
│   └── tests
│       └── test-connection.yaml
└── values.yaml

apiVersion: v2
name: five_minute_learn
description: A Helm chart for Kubernetes

# A chart can be either an 'application' or a 'library' chart.
#
# Application charts are a collection of templates that can be packaged into versioned archives
# to be deployed.
#
# Library charts provide useful utilities or functions for the chart developer. They're included as
# a dependency of application charts to inject those utilities and functions into the rendering
# pipeline. Library charts do not define any templates and therefore cannot be deployed.
type: application

# This is the chart version. This version number should be incremented each time you make changes
# to the chart and its templates, including the app version.
# Versions are expected to follow Semantic Versioning (https://semver.org/)
version: 0.1.0

# This is the version number of the application being deployed. This version number should be
# incremented each time you make changes to the application. Versions are not expected to
# follow Semantic Versioning. They should reflect the version the application is using.
# It is recommended to use it with quotes.
appVersion: "1.16.0"

-> % tree templates
templates
├── _helpers.tpl
├── deployment.yaml
└── service.yaml

apiVersion: apps/v1 
kind: Deployment
metadata: 
name: {{ include "five_minute_learn.fullname" . }}
labels:
  {{- include "five_minute_learn.labels" . | nindent 4 }}
spec:
replicas: {{ .Values.replicaCount }}
selector:
  matchLabels:
    {{- include "five_minute_learn.selectorLabels" . | nindent 6 }}
template:
  metadata:
    {{- with .Values.podAnnotations }}
    annotations:
      {{- toYaml . | nindent 8 }}
    {{- end }}
    labels:
      {{- include "five_minute_learn.selectorLabels" . | nindent 8 }}
  spec:
    containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
        imagePullPolicy: {{ .Values.image.pullPolicy }}
        ports:
          - name: http
            containerPort: 80
            protocol: TCP

apiVersion: v1 
kind: Service
metadata: 
name: {{ include "five_minute_learn.fullname" . }}
labels:
  {{- include "five_minute_learn.labels" . | nindent 4 }}
spec:
type: {{ .Values.service.type }}
ports:
  - port: {{ .Values.service.port }}
    targetPort: {{ .Values.service.targetPort }}
    protocol: TCP
    name: {{ .Values.service.name }}
selector:
  {{- include "five_minute_learn.selectorLabels" . | nindent 4 }}

{{ .Object.Parameter }}

replicaCount: 2
image: 
repository: nginx
tag: "1.25.3"
pullPolicy: Always

service: 
name: nginx-service
type: ClusterIP
port: 80
targetPort: 8080

helm install my-chart . -f values-dev.yaml  # 在 dev 环境使用 dev 的 values 文件

 helm lint 

➜  helm lint five_minute_learn/

==> Linting five_minute_learn/

[INFO] Chart.yaml: icon is recommended

1 chart(s) linted, 0 chart(s) failed

 helm template  

# Source: five_minute_learn/templates/service.yaml
# Service 部署配置
apiVersion: v1
kind: Service
metadata:
  # 服务元数据
  name: release-name-five_minute_learn
  labels:
    # 标签
    helm.sh/chart: five_minute_learn-0.1.0
    app.kubernetes.io/name: five_minute_learn
    app.kubernetes.io/instance: release-name
    app.kubernetes.io/version: "1.0.0"
    app.kubernetes.io/managed-by: Helm
spec:
  # 服务类型为 ClusterIP
  type: ClusterIP
  ports:
    # 端口映射
    - port: 80
      targetPort: 8080
      protocol: TCP
      name: nginx-service
  selector:
    # 选择器
    app.kubernetes.io/name: five_minute_learn
    app.kubernetes.io/instance: release-name
---
# Source: five_minute_learn/templates/deployment.yaml
# Deployment 部署配置
apiVersion: apps/v1
kind: Deployment
metadata:
  # 部署元数据
  name: release-name-five_minute_learn
  labels:
    # 标签
    helm.sh/chart: five_minute_learn-0.1.0
    app.kubernetes.io/name: five_minute_learn
    app.kubernetes.io/instance: release-name
    app.kubernetes.io/version: "1.0.0"
    app.kubernetes.io/managed-by: Helm
spec:
  # 副本数为 2
  replicas: 2
  selector:
    matchLabels:
      # 选择器匹配标签
      app.kubernetes.io/name: five_minute_learn
      app.kubernetes.io/instance: release-name
  template:
    metadata:
      labels:
        # 模板标签
        app.kubernetes.io/name: five_minute_learn
        app.kubernetes.io/instance: release-name
    spec:
      containers:
        - name: five_minute_learn
          image: "nginx:1.25.3"
          imagePullPolicy: Always
          ports:
            - name: http
              containerPort: 80
              protocol: TCP

helm install --dry-run <release-name> <chart-name>