12.2 Installing Charts — helm install and Repositories

⏱️ ~6 min read

TL;DR: Add a chart repository, search for what you need, preview the default values, customize with a values.yaml, and install. The output includes connection instructions from the chart’s NOTES.txt.

Adding a Repository

# Bitnami hosts production-grade charts for most common services
helm repo add bitnami https://charts.bitnami.com/bitnami

# Other popular repos:
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo add cert-manager https://charts.jetstack.io
helm repo add prometheus https://prometheus-community.github.io/helm-charts
helm repo add grafana https://grafana.github.io/helm-charts

# Update to get the latest chart versions
helm repo update

# List configured repos
helm repo list

Finding Charts

# Search your added repos
helm search repo nginx
helm search repo postgresql

# Search ArtifactHub (the public Helm chart registry)
helm search hub nginx
helm search hub --max-col-width 80 nginx | head -20

ArtifactHub (artifacthub.io) is the central registry — like Docker Hub but for Helm charts.

Inspecting a Chart Before Installing

# See all configurable values and their defaults
helm show values bitnami/nginx

# See what the chart installs (brief description)
helm show chart bitnami/nginx

# Full chart README
helm show readme bitnami/nginx

# Preview the actual YAML that would be installed
helm template my-nginx bitnami/nginx | head -60

# Preview with your custom values applied
helm template my-nginx bitnami/nginx --values my-values.yaml | head -80

💡 Tip: Always run helm show values and helm template before installing a chart in production. You want to know what’s being created — especially for charts with many components.

Installing a Chart

Minimal install with defaults:

helm install my-nginx bitnami/nginx \
  --namespace web \
  --create-namespace

With inline value overrides:

helm install my-nginx bitnami/nginx \
  --namespace web \
  --create-namespace \
  --set replicaCount=2 \
  --set service.type=NodePort

With a custom values file (recommended for anything beyond trivial):

# nginx-values.yaml
replicaCount: 3

image:
  tag: "1.25.3"

service:
  type: ClusterIP

ingress:
  enabled: true
  hostname: myapp.local
  ingressClassName: nginx

resources:
  requests:
    cpu: "100m"
    memory: "128Mi"
  limits:
    cpu: "200m"
    memory: "256Mi"

autoscaling:
  enabled: true
  minReplicas: 2
  maxReplicas: 10
  targetCPU: 50

helm install my-nginx bitnami/nginx \
  --namespace web \
  --create-namespace \
  --values nginx-values.yaml

After Installation

# Check the release
helm status my-nginx -n web

# See all objects created
kubectl get all -n web

# See the NOTES.txt output (connection instructions from chart author)
helm status my-nginx -n web | grep -A20 "NOTES:"

# See computed values (what was actually used)
helm get values my-nginx -n web           # Your overrides only
helm get values my-nginx -n web --all     # All values (including defaults)

# See the full manifest that's running
helm get manifest my-nginx -n web

Specifying Chart Versions

# Install a specific version
helm install my-nginx bitnami/nginx --version 15.4.4

# See available versions
helm search repo bitnami/nginx --versions | head -10

--set vs --values Syntax

# --set uses dot-notation for nested values
helm install my-app bitnami/nginx \
  --set image.repository=myrepo/myapp \
  --set image.tag=v1.2.3 \
  --set ingress.enabled=true \
  --set "ingress.hosts[0].host=myapp.local"   # List items

# --values uses a YAML file (preferred for multiple values)
helm install my-app bitnami/nginx --values values.yaml

# Both can be combined — --set overrides --values
helm install my-app bitnami/nginx \
  --values base-values.yaml \
  --set image.tag=v1.2.3    # Override just the tag

⚠️ Warning: Don’t use --set for secrets (passwords, API keys). The value ends up in shell history and Helm release history. Use a separate secrets.yaml file or reference Kubernetes Secrets in the chart values.

Try It

# Add bitnami repo
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update

# Preview what nginx chart installs
helm show chart bitnami/nginx | grep -E "description|version|appVersion"

# Preview computed values for a simple install
helm template test-nginx bitnami/nginx \
  --set replicaCount=2 \
  --set service.type=ClusterIP | grep "kind:" | sort -u

# Install
helm install demo-nginx bitnami/nginx \
  --namespace helm-demo \
  --create-namespace \
  --set replicaCount=1 \
  --set service.type=NodePort

# Verify
helm list -n helm-demo
kubectl get all -n helm-demo

# Cleanup
helm uninstall demo-nginx -n helm-demo
kubectl delete namespace helm-demo

Key Takeaways

✅ Quick Check

Q1: You need to install two separate PostgreSQL instances (one for auth, one for orders) in the same namespace. How?

Q2: You have base-values.yaml with shared settings and want to override just the image tag for a hotfix. What command syntax?

Q3: helm template shows the YAML but doesn’t install it. When would you use this in a CI pipeline?