Helm Package Manager Instalaation and Usage

Helm is the package manager for Kubernetes, providing a standardized way to define, install, and manage Kubernetes applications. It simplifies complex implementacións by bundling manifests, configurations, and dependencies into reusable packages called Charts. Esta guía cubre installation, repository management, chart implementación, and creating custom charts for your Kubernetes infrastructure.

Tabla de contenidos

• Instalaation
• Helm Architecture
• Repository Management
• Working with Charts
• Custom Chart Creation
• Helm Operations
• Best Practices
• Conclusion

Instalación

Requisitos previos

Antes de instalar Helm, ensure you have:

• Kubernetes clúster running (v1.19 or later recommended)
• kubectl configured and working properly
• curl or wget installed

Instalaing Helm 3

Helm 3 is the current version with significant improvements over Helm 2, including removal of Tiller.

Using the official installation script:

curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash

Verifica la instalación:

helm version

Expected output:

version.BuildInfo{Version:"v3.14.0", GitCommit:"..."}

Manual Instalaation

Descarga the binary directly:

# Set variables
HELM_VERSION="v3.14.0"
OS="linux"
ARCH="amd64"

# Download
wget https://get.helm.sh/helm-${HELM_VERSION}-${OS}-${ARCH}.tar.gz

# Extract
tar -zxvf helm-${HELM_VERSION}-${OS}-${ARCH}.tar.gz

# Move to PATH
sudo mv ${OS}-${ARCH}/helm /usr/local/bin/

# Verify
helm version

Using Package Managers

On Ubuntu/Debian:

curl https://baltocdn.com/helm/signing.asc | gpg --dearmor | sudo tee /usr/share/keyrings/helm.gpg > /dev/null
echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/helm.gpg] https://baltocdn.com/helm/stable/debian/ all main" | sudo tee /etc/apt/sources.list.d/helm-stable-debian.list
sudo apt-get update
sudo apt-get install helm

On macOS with Homebrew:

brew install helm

Helm Completion

For bash:

helm completion bash | sudo tee /etc/bash_completion.d/helm

For zsh:

helm completion zsh | sudo tee /usr/share/zsh/site-functions/_helm

Helm Architecture

Core Components

Charts: Collections of templates and values that define Kubernetes resources. Charts are essentially parameterized Kubernetes manifests.

Releases: Instances of charts deployed to a clúster. Each release has a unique name and version.

Templates: Go template files that generate Kubernetes manifests by combining templates with values.

Values: Configuration data that parameterizes charts, allowing customization without modifying the chart itself.

Directory Structure

A typical Helm chart structure:

my-chart/
├── Chart.yaml              # Chart metadata
├── values.yaml             # Default configuration values
├── charts/                 # Dependent charts
├── templates/              # Kubernetes manifest templates
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── _helpers.tpl        # Template helpers
│   └── NOTES.txt           # Deployment notes
├── README.md               # Chart documentation
└── .helmignore             # Files to ignore when packaging

Administración de repositorios

Adding Repositories

Add the official Helm Hub repository:

helm repo add stable https://charts.helm.sh/stable
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo add jetstack https://charts.jetstack.io
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

Listing Repositories

helm repo list

Searching Charts

Search for available charts:

helm search repo mysql
helm search repo nginx --versions
helm search hub postgresql

Updating Repository Cache

helm repo update

This updates your local cache of chart information. Always run this before searching or installing charts.

Removing Repositories

helm repo remove stable

Working with Charts

Instalaing Charts

Basic installation:

helm install my-release bitnami/mysql

Specify espacio de nombres:

helm install my-release bitnami/mysql --namespace data-layer --create-namespace

Customizing Values

Override values during installation:

helm install my-release bitnami/mysql \
  --set auth.rootPassword=MyPassword123 \
  --set primary.persistence.enabled=true \
  --set primary.persistence.size=20Gi

Using a values file:

helm install my-release bitnami/mysql -f values-prod.yaml

Example values file:

# values-prod.yaml
auth:
  rootPassword: "SecurePassword123"
  database: production_db
  username: produser
  password: "ProdUserPass456"

primary:
  persistence:
    enabled: true
    size: 50Gi
    storageClass: fast-ssd
    
  resources:
    limits:
      memory: "2Gi"
      cpu: "1"
    requests:
      memory: "1Gi"
      cpu: "500m"

replica:
  replicaCount: 2
  persistence:
    enabled: true
    size: 50Gi

Listing Releases

helm list
helm list -A  # All namespaces
helm list -n production

Getting Release Information

helm status my-release
helm get values my-release
helm get manifest my-release

Creación de gráficos personalizados

Scaffolding a New Chart

Crea un new chart structure:

helm create my-web-app

This generates a complete chart template with examples.

Chart.yaml Metadata

Define chart metadata:

apiVersion: v2
name: my-web-app
description: A Helm chart for deploying a web application
type: application
version: 1.0.0
appVersion: "2.1.0"
keywords:
  - web
  - application
home: https://example.com
sources:
  - https://github.com/example/my-web-app
maintainers:
  - name: DevOps Team
    email: [email protected]

Creating Templates

Deployment template (templates/implementación.yaml):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "my-web-app.fullname" . }}
  labels:
    {{- include "my-web-app.labels" . | nindent 4 }}
spec:
  {{- if not .Values.autoscaling.enabled }}
  replicas: {{ .Values.replicaCount }}
  {{- end }}
  selector:
    matchLabels:
      {{- include "my-web-app.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      {{- with .Values.podAnnotations }}
      annotations:
        {{- toYaml . | nindent 8 }}
      {{- end }}
      labels:
        {{- include "my-web-app.selectorLabels" . | nindent 8 }}
    spec:
      containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
        imagePullPolicy: {{ .Values.image.pullPolicy }}
        ports:
        - name: http
          containerPort: 8080
          protocol: TCP
        livenessProbe:
          httpGet:
            path: /health
            port: http
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /ready
            port: http
          initialDelaySeconds: 5
          periodSeconds: 5
        resources:
          {{- toYaml .Values.resources | nindent 12 }}

Service template (templates/servicio.yaml):

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

Default Values

values.yaml configuration:

replicaCount: 3

image:
  repository: my-registry.azurecr.io/my-web-app
  pullPolicy: IfNotPresent
  tag: "1.0.0"

imagePullSecrets: []

nameOverride: ""
fullnameOverride: ""

podAnnotations:
  prometheus.io/scrape: "true"
  prometheus.io/port: "8080"
  prometheus.io/path: "/metrics"

podSecurityContext:
  runAsNonRoot: true
  runAsUser: 1000
  fsGroup: 1000

securityContext:
  capabilities:
    drop:
    - ALL
  readOnlyRootFilesystem: true
  allowPrivilegeEscalation: false

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: true
  className: "nginx"
  annotations:
    cert-manager.io/cluster-issuer: "letsencrypt-prod"
  hosts:
    - host: "myapp.example.com"
      paths:
        - path: /
          pathType: Prefix
  tls:
    - secretName: myapp-tls
      hosts:
        - myapp.example.com

resources:
  limits:
    cpu: 500m
    memory: 512Mi
  requests:
    cpu: 250m
    memory: 256Mi

autoscaling:
  enabled: true
  minReplicas: 3
  maxReplicas: 10
  targetCPUUtilizationPercentage: 80

Validating Charts

helm lint my-web-app

Packaging Charts

helm package my-web-app

This creates my-web-app-1.0.0.tgz ready for distribution.

Operaciones de Helm

Upgrading Releases

helm upgrade my-release bitnami/mysql \
  --set auth.rootPassword=NewPassword123

Dry-run before upgrade:

helm upgrade my-release bitnami/mysql --dry-run --debug

Rolling Back Releases

View release history:

helm history my-release

Rollback to previous release:

helm rollback my-release

Rollback to specific revision:

helm rollback my-release 2

Uninstalling Releases

helm uninstall my-release

Keep release history:

helm uninstall my-release --keep-history

Pruebas Charts

helm test my-release

Debugging

Get rendered templates without installing:

helm template my-release bitnami/mysql

Instala with debug output:

helm install my-release bitnami/mysql --debug

Mejores prácticas

Version Management

Always pin chart versions in production:

helm install my-release bitnami/mysql --version 11.3.4

Values Organization

Use multiple values files for different environments:

# Development
helm install dev-release my-chart -f values-base.yaml -f values-dev.yaml

# Production
helm install prod-release my-chart -f values-base.yaml -f values-prod.yaml

Consideraciones de seguridad

Store sensitive values in Kubernetes Secrets:

kubectl create secret generic app-secrets \
  --from-literal=db-password=SecurePass123 \
  --from-literal=api-key=ApiKey456

helm install my-release my-chart \
  --set-string externalSecrets.dbPassword='$db-password' \
  --set-string externalSecrets.apiKey='$api-key'

Pruebas and Validation

Before production implementación:

helm lint my-chart
helm template my-release my-chart --validate
helm install my-release my-chart --dry-run --debug

Documentation

Document your charts thoroughly:

# README.md included in chart
# NOTES.txt for post-install information
# values.yaml with comments explaining each option

Conclusión

Helm is essential for managing Kubernetes implementacións at scale. Mastering Helm enables you to standardize application implementación, maintain consistency across environments, and reduce manual configuration errors. By following these practices for repository management, custom chart creation, and implementación operations, you'll build a robust and maintainable Kubernetes infrastructure on your VPS or baremetal servers. Regularly update your charts, maintain clear documentation, and implement proper version control to ensure smooth operations and easy rollbacks when needed.