kubernetes-helm-deployments

name	kubernetes-helm-deployments
metadata	{"category":"Containerization and Orchestration"}
description	Master enterprise Kubernetes Helm chart creation, templating, values schema validation, dry-run testing, releases, and rollback management. Trigger when writing Helm charts, configuring K8s deployments, or managing cloud-native releases.
compatibility	Kubernetes 1.25+, Helm v3.10+, kubectl, YAML

Kubernetes Helm Deployments Skill Guide

This skill provides production standards, directory layouts, templating practices, and release management rules for building enterprise-grade Kubernetes Helm charts.

---

1. Helm Chart Directory Layout & Architecture

Always follow the standard Helm v3 Chart layout:

my-app/
├── Chart.yaml             # Chart metadata, versioning, and dependencies
├── values.yaml            # Default configuration values
├── values.schema.json     # JSON Schema for values validation
├── README.md              # Documentation for chart consumers
├── templates/
│   ├── _helpers.tpl       # Named templates and reusable template helpers
│   ├── deployment.yaml    # Kubernetes Deployment manifest
│   ├── service.yaml       # Kubernetes Service manifest
│   ├── ingress.yaml       # Kubernetes Ingress manifest
│   ├── hpa.yaml           # HorizontalPodAutoscaler manifest
│   ├── configmap.yaml     # ConfigMap for application configuration
│   └── NOTES.txt          # Post-installation status output
└── tests/
    └── test-connection.yaml # Helm test pod definition

---

2. Chart Metadata & Validation (Chart.yaml & values.schema.json)

A. Chart Metadata (Chart.yaml)

apiVersion: v2
name: my-app
description: Production microservice deployment chart for my-app
type: application
version: 1.4.0
appVersion: "2.18.1"
maintainers:
  - name: Platform Engineering
    email: [e-mail]
dependencies:
  - name: postgresql
    version: 12.5.2
    repository: https://charts.bitnami.com/bitnami
    condition: postgresql.enabled

B. Values Schema Validation (values.schema.json)

Enforce strong typing on input variables to prevent invalid deployments:

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "required": ["replicaCount", "image", "service"],
  "properties": {
    "replicaCount": {
      "type": "integer",
      "minimum": 1,
      "maximum": 50
    },
    "image": {
      "type": "object",
      "required": ["repository", "tag", "pullPolicy"],
      "properties": {
            
            
         
           
             
        
      
    
     
       
        
    
  

---

3. Template Helpers (templates/_helpers.tpl)

Define strict helper templates for consistent naming, labels, and selector labels.

{{/*
Expand the name of the chart.
*/}}
{{- define "my-app.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
{{- end }}

{{/*
Create a default fully qualified app name.
*/}}
{{- define "my-app.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- $name := default .Chart.Name .Values.nameOverride }}
{{- if contains $name .Release.Name }}
{{- .Release.Name | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}
{{- end }}

{{/*
Common labels appended to all resources.
*/}}
{{- define "my-app.labels" -}}
helm.sh/chart: {{ printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
{{ include "my-app.selectorLabels" . }}
{{- if .Chart.AppVersion }}
app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
{{- end }}
app.kubernetes.io/managed-by: {{ .Release.Service }}
{{- end }}

{{/*
Selector labels used by deployments and services.
*/}}
{{- define "my-app.selectorLabels" -}}
app.kubernetes.io/name: {{ include "my-app.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end }}

---

4. Production Manifest Templates

A. Deployment Manifest (templates/deployment.yaml)

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "my-app.fullname" . }}
  labels:
    {{- include "my-app.labels" . | nindent 4 }}
spec:
  {{- if not .Values.autoscaling.enabled }}
  replicas: {{ .Values.replicaCount }}
  {{- end }}
  selector:
    matchLabels:
      {{- include "my-app.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      labels:
        {{- include "my-app.selectorLabels" . | nindent 8 }}
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
    spec:
      
         
         
         
         
      
          {{  }}
           
           {{  }}
          
              
               {{  }}
               
          
            
               
               
             
             
          
            
               
               
             
             
          
            {{      }}

B. Service Manifest (templates/service.yaml)

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

---

5. Helm Lifecycle Management & Testing Commands

# 1. Lint chart syntax and structure
helm lint ./my-app

# 2. Perform local dry-run rendering with schema validation
helm template my-release ./my-app --values ./my-app/values.yaml --debug

# 3. Perform dry-run installation against actual Kubernetes API server
helm install my-release ./my-app --dry-run --debug

# 4. Idempotent atomic upgrade/install with timeout and rollback on failure
helm upgrade --install my-release ./my-app \
  --namespace production \
  --create-namespace \
  --values ./my-app/values.yaml \
  --atomic \
  --timeout 5m0s

# 5. Rollback release to previous version if needed
helm rollback my-release 1 --namespace production

---

6. Anti-Patterns & Best Practices

Anti-Pattern	Operational Risk	Production Best Practice
Hardcoding image tags as latest	Unpredictable rollouts and loss of determinism across environments.	Always pin explicit semantic versions or git SHAs in image.tag.
Omitting container resource limits/requests	Triggers noisy-neighbor resource starvation and OOM kills.	Mandate CPU/Memory requests and limits via values.schema.json.
Skipping ConfigMap/Secret checksum annotations	Pods do not restart automatically when configurations change.	Include checksum/config annotation using sha256sum in Deployment templates.
Deploying without --atomic or --wait flags in CI	Failed deployments remain in broken intermediate states.	Use --atomic --timeout 5m so Helm automatically rolls back on deployment failure.