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

### Install the chart
```bash
# 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
```bash
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:
```yaml
ingress:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
```

For cert-manager SSL certificates:
```yaml
ingress:
  annotations:
    cert-manager.io/cluster-issuer: "letsencrypt-prod"
```

## TLS Configuration

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

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

Then enable it in values.yaml:
```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

```bash
# 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.