基于base-microservice父Chart创建customapp子Chart的Helm配置咨询

Alright, let's walk through setting up your customapp Chart that inherits from the base-microservice parent Chart, including dependency configuration, template overrides, and values customization.

1. Create the Target Directory Structure #

First, build out the directory structure exactly as you specified. You can use these commands to scaffold it quickly:

mkdir -p customapp-service/customapp/{charts,templates,src}
touch customapp-service/customapp/{Chart.yaml,requirements.yaml,values.yaml}

The final structure will look like this:

customapp-service
└── customapp
    ├── Chart.yaml
    ├── charts
    ├── requirements.yaml
    ├── values.yaml
    ├── src          # For app code, custom helper scripts, or extra templates
    └── templates    # For overriding parent Chart templates (optional)

2. Configure Dependencies (Link to Parent Chart) #

Update the requirements.yaml to declare a dependency on your base-microservice Chart. This tells Helm where to pull the parent Chart from:

# customapp/requirements.yaml
dependencies:
  - name: base-microservice
    version: "0.1.0"
    repository: "https://mycompany.github.com/pages/base-microservice"

Alternatively, for Helm 3+, you can define dependencies directly in Chart.yaml (this replaces requirements.yaml in newer versions):

# customapp/Chart.yaml
apiVersion: v2
name: customapp
description: A custom microservice inheriting from base-microservice
version: 0.1.0
dependencies:
  - name: base-microservice
    version: "0.1.0"
    repository: "https://mycompany.github.com/pages/base-microservice"

After setting up dependencies, run helm dependency build to pull the parent Chart into the charts directory.

3. Override Parent Chart Values #

To customize the parent Chart's default configuration, update your customapp/values.yaml with the values you want to override. Use the parent Chart's name as a top-level key to target its values:

# customapp/values.yaml
# Override base-microservice's default values
base-microservice:
  # Example: Override deployment replica count
  replicaCount: 3
  # Example: Update service port
  service:
    port: 8080
  # Example: Customize ingress host
  ingress:
    hosts:
      - host: customapp.mycompany.com
        paths: ["/"]

# Add custom values specific to customapp (if needed)
customapp:
  image:
    repository: mycompany/customapp
    tag: v1.0.0

Helm will merge these values with the parent Chart's values.yaml, with your overrides taking precedence.

4. Override Parent Chart Templates #

If you need to modify the parent Chart's templates (like deployment.yaml, service.yaml, etc.), create a 同名模板文件 in customapp/templates/. Helm will prioritize the child Chart's template over the parent's when rendering.

For example, to override the parent's deployment.yaml:

# customapp/templates/deployment.yaml
# Start with the parent's template content, then modify as needed
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "base-microservice.fullname" . }}
  labels:
    {{- include "base-microservice.labels" . | nindent 4 }}
    # Add custom label for customapp
    app.kubernetes.io/component: customapp
spec:
  replicas: {{ .Values.base-microservice.replicaCount }}
  selector:
    matchLabels:
      {{- include "base-microservice.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      {{- with .Values.podAnnotations }}
      annotations:
        {{- toYaml . | nindent 8 }}
      {{- end }}
      labels:
        {{- include "base-microservice.selectorLabels" . | nindent 8 }}
        app.kubernetes.io/component: customapp
    spec:
      {{- with .Values.imagePullSecrets }}
      imagePullSecrets:
        {{- toYaml . | nindent 8 }}
      {{- end }}
      containers:
        - name: {{ .Chart.Name }}
          # Use customapp's image instead of parent's default
          image: "{{ .Values.customapp.image.repository }}:{{ .Values.customapp.image.tag }}"
          imagePullPolicy: {{ .Values.imagePullPolicy }}
          ports:
            - name: http
              containerPort: {{ .Values.base-microservice.service.port }}
              protocol: TCP
          # Add custom liveness/readiness probes for customapp
          livenessProbe:
            httpGet:
              path: /healthz
              port: http
            initialDelaySeconds: 10
            periodSeconds: 5
          readinessProbe:
            httpGet:
              path: /readyz
              port: http
            initialDelaySeconds: 5
            periodSeconds: 3
          {{- with .Values.resources }}
          resources:
            {{- toYaml . | nindent 12 }}
          {{- end }}

This way, you retain the parent Chart's base structure but inject customizations specific to customapp.

5. Using the src Directory #

The src directory can be used for:

• Custom application code (if you're packaging the app with the Chart)
• Helper scripts (e.g., pre-install/post-upgrade hooks)
• Additional template fragments that don't override parent templates (you can include these in your custom templates using {{ include "customapp.my-helper" . }})

内容的提问来源于stack exchange，提问作者hackmabrain