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Cover image for Part 8: Helm - Packaging Kubernetes Applications
David Nwosu
David Nwosu

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Part 8: Helm - Packaging Kubernetes Applications

#helm #gitops #devops

Series: From "Just Put It on a Server" to Production DevOps

Reading time: 15 minutes

Level: Intermediate

The YAML Duplication Problem

In Part 6, we deployed our SSPP platform to Kubernetes. It works! But look at your k8s/ directory:

k8s/
├── api-deployment.yaml
├── api-service.yaml
├── api-configmap.yaml
├── worker-deployment.yaml
├── worker-configmap.yaml
├── redis-deployment.yaml
├── redis-service.yaml
├── postgres-statefulset.yaml
├── postgres-service.yaml
└── ...
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Now your manager says:

"We need dev, staging, and prod environments."

Your first thought: Copy-paste all YAML files three times:

k8s/
├── dev/
│   ├── api-deployment.yaml  # replicas: 1, resources: small
│   ├── api-service.yaml
│   └── ...
├── staging/
│   ├── api-deployment.yaml  # replicas: 2, resources: medium
│   ├── api-service.yaml
│   └── ...
└── prod/
    ├── api-deployment.yaml  # replicas: 5, resources: large
    ├── api-service.yaml
    └── ...
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What changes between environments?

  • Replica counts
  • Resource limits
  • Image tags
  • Database URLs
  • Domain names
  • Storage sizes

What stays the same?

  • Container ports
  • Health check paths
  • Service types
  • Label selectors
  • Volume mount paths

You're copying 80% identical YAML and changing 20%.

Then a bug is found: API health check path should be /health not /healthz.

Now you need to update it in 3 places. And you miss one. Staging is broken. Users are angry.

This is the YAML duplication problem.

What is Helm?

Helm is a package manager for Kubernetes applications.

Beginner mental model:

Helm is like apt-get (Linux) or Homebrew (Mac) for Kubernetes apps.

Instead of managing 20+ YAML files per environment, you create a Helm Chart—a template with variables:

# templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Values.name }}
spec:
  replicas: {{ .Values.replicas }}
  template:
    spec:
      containers:
      - name: api
        image: {{ .Values.image.repository }}:{{ .Values.image.tag }}
        resources:
          limits:
            cpu: {{ .Values.resources.cpu }}
            memory: {{ .Values.resources.memory }}
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Then you have different values files per environment:

# values-dev.yaml
name: sspp-api
replicas: 1
image:
  repository: davidbrown77/sspp-api
  tag: dev-latest
resources:
  cpu: "500m"
  memory: "512Mi"

# values-prod.yaml
name: sspp-api
replicas: 5
image:
  repository: davidbrown77/sspp-api
  tag: v1.2.3
resources:
  cpu: "2000m"
  memory: "4Gi"
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Deploy with:

# Dev
helm install sspp-api ./charts/api -f values-dev.yaml

# Prod
helm install sspp-api ./charts/api -f values-prod.yaml
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Same template, different values. DRY (Don't Repeat Yourself) for Kubernetes.

Helm Concepts

Charts

A Helm Chart is a package of Kubernetes manifests.

Structure:

charts/api/
├── Chart.yaml          # Metadata (name, version)
├── values.yaml         # Default values
├── templates/          # Templated Kubernetes manifests
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── configmap.yaml
│   └── ingress.yaml
└── charts/             # Dependencies (sub-charts)
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Values

values.yaml defines default configuration:

replicaCount: 3

image:
  repository: davidbrown77/sspp-api
  tag: latest
  pullPolicy: IfNotPresent

service:
  type: ClusterIP
  port: 3000

resources:
  limits:
    cpu: 1000m
    memory: 1Gi
  requests:
    cpu: 500m
    memory: 512Mi
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Override with:

helm install sspp-api ./charts/api \
  --set replicaCount=5 \
  --set image.tag=v1.2.3
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Or use a values file:

helm install sspp-api ./charts/api -f prod-values.yaml
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Templates

Templates use Go templating syntax:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "api.fullname" . }}
  labels:
    {{- include "api.labels" . | nindent 4 }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      {{- include "api.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      labels:
        {{- include "api.selectorLabels" . | nindent 8 }}
    spec:
      containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
        ports:
        - name: http
          containerPort: {{ .Values.service.port }}
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Template functions:

  • {{ .Values.replicaCount }} - Access values
  • {{ include "helper" . }} - Reuse templates
  • {{- if .Values.enabled }} - Conditionals
  • {{- range .Values.items }} - Loops

Creating a Helm Chart for SSPP API

Initialize Chart 

cd infrastructure
helm create charts/api
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This generates a basic chart structure.

Define Chart.yaml 

apiVersion: v2
name: sspp-api
description: Sales Signal Processing Platform API
type: application
version: 1.0.0
appVersion: "1.0.0"
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Create Templates

templates/deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Values.name }}
  labels:
    app: {{ .Values.name }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ .Values.name }}
  template:
    metadata:
      labels:
        app: {{ .Values.name }}
    spec:
      containers:
      - name: api
        image: {{ .Values.image.repository }}:{{ .Values.image.tag }}
        ports:
        - containerPort: 3000
        env:
        - name: DATABASE_URL
          value: {{ .Values.database.url }}
        - name: REDIS_URL
          value: {{ .Values.redis.url }}
        {{- if .Values.env }}
        {{- range $key, $value := .Values.env }}
        - name: {{ $key }}
          value: {{ $value | quote }}
        {{- end }}
        {{- end }}
        resources:
          limits:
            cpu: {{ .Values.resources.limits.cpu }}
            memory: {{ .Values.resources.limits.memory }}
          requests:
            cpu: {{ .Values.resources.requests.cpu }}
            memory: {{ .Values.resources.requests.memory }}
        livenessProbe:
          httpGet:
            path: /health
            port: 3000
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /health
            port: 3000
          initialDelaySeconds: 5
          periodSeconds: 5
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templates/service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: {{ .Values.name }}
  labels:
    app: {{ .Values.name }}
spec:
  type: {{ .Values.service.type }}
  ports:
  - port: {{ .Values.service.port }}
    targetPort: 3000
    protocol: TCP
    name: http
  selector:
    app: {{ .Values.name }}
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Define Values

values.yaml:

name: sspp-api
replicaCount: 3

image:
  repository: davidbrown77/sspp-api
  tag: latest
  pullPolicy: IfNotPresent

service:
  type: ClusterIP
  port: 3000

database:
  url: "postgresql://user:pass@postgres:5432/sspp"

redis:
  url: "redis://redis:6379"

resources:
  limits:
    cpu: "1000m"
    memory: "1Gi"
  requests:
    cpu: "500m"
    memory: "512Mi"

env: {}
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values-dev.yaml:

name: sspp-api
replicaCount: 1
image:
  tag: dev-latest
resources:
  limits:
    cpu: "500m"
    memory: "512Mi"
  requests:
    cpu: "250m"
    memory: "256Mi"
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values-prod.yaml:

name: sspp-api
replicaCount: 5
image:
  tag: v1.2.3
  pullPolicy: Always
resources:
  limits:
    cpu: "2000m"
    memory: "4Gi"
  requests:
    cpu: "1000m"
    memory: "2Gi"
env:
  LOG_LEVEL: "info"
  NODE_ENV: "production"
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Deploying with Helm

Install 

# Dev environment
helm install sspp-api ./charts/api -f values-dev.yaml

# Prod environment (different namespace)
helm install sspp-api ./charts/api \
  -f values-prod.yaml \
  -n production \
  --create-namespace
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Upgrade 

# Update image tag
helm upgrade sspp-api ./charts/api \
  --set image.tag=v1.3.0 \
  --reuse-values
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Rollback 

# Rollback to previous release
helm rollback sspp-api

# Rollback to specific revision
helm rollback sspp-api 3
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List Releases 

helm list
helm list -n production
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Get Values 

# See computed values
helm get values sspp-api

# See all values (including defaults)
helm get values sspp-api --all
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Helm for Worker Service

Create a similar chart for the worker:

helm create charts/worker
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Key differences from API:

  • No Service (worker doesn't expose HTTP)
  • Different environment variables
  • Different resource requirements

values.yaml:

name: sspp-worker
replicaCount: 2

image:
  repository: davidbrown77/sspp-worker
  tag: latest

redis:
  url: "redis://redis:6379"

database:
  url: "postgresql://user:pass@postgres:5432/sspp"

resources:
  limits:
    cpu: "1000m"
    memory: "2Gi"
  requests:
    cpu: "500m"
    memory: "1Gi"
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Benefits of Helm

✅ DRY Principle:

  • One template, multiple environments
  • Change once, deploy everywhere

✅ Version Control:

  • Track changes to chart versions
  • Rollback to any previous release

✅ Parameterization:

  • Override any value at deployment
  • No hardcoded configuration

✅ Package Management:

  • Share charts via Helm repositories
  • Reuse community charts (PostgreSQL, Redis, etc.)

✅ Release Management:

  • Track deployment history
  • Easy rollbacks

What's Next?

Helm solved packaging and templating, but we still have deployment problems:

❌ Manual deployments - Someone must run helm upgrade

❌ No Git sync - Cluster state can drift from Git

❌ No automation - Still need CI/CD triggers

❌ Configuration drift - Manual kubectl changes go untracked

In Part 9, we'll add GitOps with ArgoCD.

You'll learn:

  • Git as single source of truth (not your laptop)
  • Automatic sync from Git → Cluster
  • Self-healing (ArgoCD reverts manual changes)
  • One-click rollbacks through UI
  • Deployment history and audit trails
  • Progressive delivery (blue/green, canary)

Spoiler: Push to Git → ArgoCD deploys automatically. This is GitOps.

Try It Yourself

Create Helm charts for all SSPP services:

  1. API chart - Deployment + Service + Ingress
  2. Worker chart - Deployment only
  3. Redis chart - Or use bitnami/redis from Helm Hub
  4. PostgreSQL chart - Or use bitnami/postgresql

Test multi-environment setup:

# Deploy dev
helm install sspp ./charts/api -f values-dev.yaml -n dev --create-namespace

# Deploy prod
helm install sspp ./charts/api -f values-prod.yaml -n production --create-namespace

# Compare
kubectl get pods -n dev
kubectl get pods -n production
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Bonus: Package your chart and push to a Helm repository (GitHub Pages, ChartMuseum, or OCI registry).

Next: Automating Deployments

In Part 9, we'll solve the manual deployment problem:

"How do we automatically deploy when code is merged to Git?"

We'll use Argo CD to implement GitOps:

  • Git becomes the source of truth
  • Changes are automatically synced to cluster
  • Drift is detected and corrected
  • Deployments are auditable and traceable

But spoiler: GitOps solves deployment automation, but not the full picture. We'll still need observability and production hardening.

Previous: Part 7: Terraform - Making Infrastructure Repeatable

Next: Part 9: GitOps with Argo CD

About the Author

Building this series to demonstrate real DevOps thinking for my Proton.ai application. If you're hiring for platform engineering roles, let's connect.

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