Helm

Helm Package Management

Executive Summary

Production-grade Helm chart development and management covering template syntax, values schema, release lifecycle, and CI/CD integration. This skill provides deep expertise in creating maintainable, reusable charts for enterprise Kubernetes deployments.

Core Competencies

1. Chart Structure

Production Chart Layout

myapp/
├── Chart.yaml
├── Chart.lock
├── values.yaml
├── values.schema.json
├── README.md
├── templates/
│   ├── _helpers.tpl
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── hpa.yaml
│   ├── pdb.yaml
│   ├── serviceaccount.yaml
│   ├── servicemonitor.yaml
│   └── NOTES.txt
├── charts/
└── tests/
    └── test-connection.yaml

Chart.yaml

apiVersion: v2
name: myapp
description: Production API Server
type: application
version: 1.2.0
appVersion: "2.1.0"
keywords:
- api
- backend
maintainers:
- name: Platform Team
  email: platform@example.com
dependencies:
- name: redis
  version: "18.x.x"
  repository: https://charts.bitnami.com/bitnami
  condition: redis.enabled

2. Template Best Practices

_helpers.tpl

{{- define "myapp.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
{{- end }}

{{- define "myapp.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- $name := default .Chart.Name .Values.nameOverride }}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}

{{- define "myapp.labels" -}}
helm.sh/chart: {{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}
app.kubernetes.io/name: {{ include "myapp.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/version: {{ .Values.image.tag | default .Chart.AppVersion | quote }}
app.kubernetes.io/managed-by: {{ .Release.Service }}
{{- end }}

{{- define "myapp.selectorLabels" -}}
app.kubernetes.io/name: {{ include "myapp.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end }}

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "myapp.fullname" . }}
  labels:
    {{- include "myapp.labels" . | nindent 4 }}
spec:
  {{- if not .Values.autoscaling.enabled }}
  replicas: {{ .Values.replicaCount }}
  {{- end }}
  selector:
    matchLabels:
      {{- include "myapp.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
      labels:
        {{- include "myapp.selectorLabels" . | nindent 8 }}
    spec:
      serviceAccountName: {{ include "myapp.fullname" . }}
      securityContext:
        {{- toYaml .Values.podSecurityContext | nindent 8 }}
      containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
        imagePullPolicy: {{ .Values.image.pullPolicy }}
        ports:
        - name: http
          containerPort: {{ .Values.service.targetPort }}
        {{- with .Values.resources }}
        resources:
          {{- toYaml . | nindent 12 }}
        {{- end }}
        {{- if .Values.probes.liveness.enabled }}
        livenessProbe:
          httpGet:
            path: {{ .Values.probes.liveness.path }}
            port: http
          initialDelaySeconds: {{ .Values.probes.liveness.initialDelaySeconds }}
        {{- end }}

3. Values Schema

values.schema.json

{
  "$schema": "https://json-schema.org/draft-07/schema#",
  "type": "object",
  "required": ["image", "replicaCount"],
  "properties": {
    "replicaCount": {
      "type": "integer",
      "minimum": 1,
      "description": "Number of replicas"
    },
    "image": {
      "type": "object",
      "required": ["repository"],
      "properties": {
        "repository": {
          "type": "string"
        },
        "tag": {
          "type": "string"
        },
        "pullPolicy": {
          "type": "string",
          "enum": ["Always", "IfNotPresent", "Never"]
        }
      }
    },
    "resources": {
      "type": "object",
      "properties": {
        "requests": {
          "type": "object"
        },
        "limits": {
          "type": "object"
        }
      }
    }
  }
}

4. Release Management

Common Operations

# Install with values
helm install myapp ./myapp \
  -n production \
  -f values-prod.yaml \
  --set image.tag=v2.1.0

# Upgrade
helm upgrade myapp ./myapp \
  -n production \
  -f values-prod.yaml \
  --atomic \
  --timeout 5m

# Rollback
helm rollback myapp 2 -n production

# History
helm history myapp -n production

# Diff (with helm-diff plugin)
helm diff upgrade myapp ./myapp -n production -f values-prod.yaml

5. Hooks

Pre-upgrade Migration

apiVersion: batch/v1
kind: Job
metadata:
  name: {{ include "myapp.fullname" . }}-migrate
  annotations:
    "helm.sh/hook": pre-upgrade
    "helm.sh/hook-weight": "-5"
    "helm.sh/hook-delete-policy": hook-succeeded
spec:
  template:
    spec:
      restartPolicy: Never
      containers:
      - name: migrate
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
        command: ["./migrate.sh"]

Integration Patterns

Uses skill: gitops

• Chart versioning
• ArgoCD integration

Coordinates with skill: deployments

• Release strategies
• Rollback management

Works with skill: monitoring

• ServiceMonitor templates
• Metrics configuration

Troubleshooting Guide

Decision Tree: Helm Issues

Helm Problem?
│
├── Template error
│   ├── helm template . --debug
│   ├── Check indentation
│   └── Verify values exist
│
├── Upgrade failed
│   ├── Check hook failures
│   ├── Verify resources
│   └── Use --atomic
│
└── Release stuck
    ├── helm rollback
    ├── Check pending hooks
    └── Delete stuck resources

Debug Commands

# Debug template
helm template myapp . --debug 2>&1 | head -100

# Dry run
helm upgrade myapp . --dry-run --debug

# Get values
helm get values myapp -n production
helm get manifest myapp -n production

# Lint
helm lint .

Common Challenges & Solutions

Success Criteria

Resources

• Helm Documentation
• Chart Best Practices
• Helm Template Functions