Basic Application Helm Chart

Overview

This Helm chart deploys a basic application on a Kubernetes cluster with the following components:

• A deployment with configurable replicas
• A persistent volume claim for data storage
• A service for internal communication
• An ingress for external access with TLS support

Prerequisites

• Kubernetes 1.19+
• Helm 3.0+
• PV provisioner support in the underlying infrastructure
• Ingress controller (e.g., nginx-ingress)

Installation

Add the repository

# If hosted in a Helm repository
helm repo add my-repo https://charts.example.com
helm repo update

Install the chart

# Using default values
helm install my-release .

# Using custom values file
helm install my-release . -f values.yaml

# Using --set
helm install my-release . --set ingress.hosts[0].host=example.com

Uninstallation

helm uninstall my-release

Configuration

The following table lists the configurable parameters of the chart and their default values.

Parameter	Description	Default
replicaCount	Number of replicas	1
image.repository	Image repository	nginx
image.tag	Image tag	latest
image.pullPolicy	Image pull policy	IfNotPresent
service.type	Kubernetes service type	ClusterIP
service.port	Kubernetes service port	80
ingress.enabled	Enable ingress	true
ingress.className	Ingress class name	nginx
ingress.annotations	Ingress annotations	{}
ingress.hosts[0].host	Hostname	chart-example.local
ingress.hosts[0].paths[0].path	Path	/
ingress.hosts[0].paths[0].pathType	Path type	Prefix
ingress.tls.enabled	Enable TLS	true
ingress.tls.secretName	TLS secret name	chart-example-tls
persistence.enabled	Enable persistence	true
persistence.accessMode	PVC access mode	ReadWriteOnce
persistence.size	PVC size	1Gi
persistence.storageClass	PVC storage class	""

Ingress Annotations Examples

For NGINX ingress controller:

ingress:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/ssl-redirect: "true"

For cert-manager SSL certificates:

ingress:
  annotations:
    cert-manager.io/cluster-issuer: "letsencrypt-prod"

TLS Configuration

To use TLS, create a TLS secret in the namespace:

kubectl create secret tls chart-example-tls \
  --cert=path/to/tls.cert \
  --key=path/to/tls.key

Then enable it in values.yaml:

ingress:
  tls:
    enabled: true
    secretName: chart-example-tls
    hosts:
      - chart-example.local

Persistence

The chart mounts a Persistent Volume at /data. The volume is created using dynamic volume provisioning.

Upgrading

# Upgrade using values file
helm upgrade my-release . -f values.yaml

# Upgrade with --set flag
helm upgrade my-release . --set replicaCount=3

Limitations

• The chart has been tested on Kubernetes 1.19+
• Persistent volume provisioning support in underlying infrastructure
• Ingress controller must be present in the cluster

Contributing

If you find any issues with this chart or want to contribute improvements:

1. Fork the repository
2. Create a new branch for your changes
3. Submit a pull request

License

This Helm chart is licensed under the MIT License.