# Todo App Kubernetes Deployment

This repository contains the Kubernetes configuration files to deploy my Todo App.

## Description

The Todo App is a web application for creating, reading, updating, and deleting tasks. It is built using Node.js and is containerized using Docker. The application uses a PostgreSQL database to store task data.

## Containers Used

- **elineen/todo-app:latest**: The main application container that runs the Todo App.
- **postgres:latest**: The container that runs the PostgreSQL database.

## Kubernetes Objects

- **Namespace**: `namespace.yaml` - The namespace in which all other objects are created.
- **Deployment**: `deployment.yaml` - Defines the deployment configuration for the Todo App.
- **StatefulSet**: `statefulset.yaml` - Defines the stateful set configuration for the Todo App, including PersistentVolume and PersistentVolumeClaim objects.
- **Service**: `service.yaml` - Exposes the Todo App to the network.
- **Database Deployment**: `db-deployment.yaml` - Defines the deployment configuration for the PostgreSQL database.
- **Database Service**: `db-service.yaml` - Exposes the PostgreSQL database to the network within the cluster.

## Virtual Networks and Named Volumes

- **PersistentVolume**: Defines a persistent volume for storing application data.
- **PersistentVolumeClaim**: Claims the persistent volume for use by the StatefulSet.
- **Database PersistentVolume**: Defines a persistent volume for storing database data.
- **Database PersistentVolumeClaim**: Claims the persistent volume for use by the PostgreSQL database.

## Container Configuration

The container configuration includes the following:
- **Application Image**: `elineen/todo-app:latest`
- **Database Image**: `postgres:latest`
- **Ports**: The application listens on port 8080. The PostgreSQL database listens on port 5432.
- **Volume Mounts**: The application container mounts the persistent volume at `/data`. The PostgreSQL container mounts the persistent volume at the default data directory.

## Database Configuration
The application uses a PostgreSQL database to store task data. The database is configured with the following environment variables:

- **POSTGRES_DB**: mydatabase
- **POSTGRES_USER**: myuser
- **POSTGRES_PASSWORD**: mypassword

## Instructions

### Prerequisites

- Kubernetes cluster (e.g., Minikube, Docker Desktop, or a cloud provider like GKE, EKS, AKS)
- `kubectl` command-line tool installed and configured to interact with your Kubernetes cluster
- Docker installed and configured to pull images from Docker Hub

### Prepare the Application

Run the following script to prepare the application, build the Docker image, and create the persistent volumes:

```bash
./prepare-app.sh
```
### Start the Application

Run the following script to create all Kubernetes objects and start the application:

```
./start-app.sh
```
### View the Application

If you are using a LoadBalancer service, you can access the application using the external IP address provided by the service. Run the following command to get the service details:

```
kubectl get services -n my-namespace
```
Open a web browser, enter this sentence and replace <external-ip> with the external IP address obtained from the previous step.

```
http://<external-ip>
```
Another way can also be by using Minikube:
```
minikube service web-app-service -n my-namespace
```
### Stop the Application

Run the following script to delete all created Kubernetes objects and stop the application:

```bash
./stop-app.sh
```

This is it, your Todo-List is working, enjoy!