# Vigimétéo – Kubernetes Deployment (z2)

---

## 1. Application description

**Vigimétéo** is a weather monitoring web application.  
Users can log in, browse weather stations, consult meteorological data (wind, temperature, pressure…) and manage objects depending on their role.

The stack is made of three services:
- A **React** frontend served by Nginx
- A **Java / Vert.x** REST backend that exposes the API
- A **PostgreSQL** database that stores all data

---

## 2. Containers used

| Container | Image | Role |
|---|---|---|
| `vigimeteo-frontend` | `vigimeteo-frontend:latest` (built from `Front-end/Dockerfile`) | React SPA built with Vite, served by Nginx on port 80 |
| `vigimeteo-backend` | `vigimeteo-backend:latest` (built from `Back-end/Dockerfile`) | Java 17 / Vert.x REST API on port 8888. Connects to PostgreSQL using environment variables |
| `postgres` | `postgres:17-alpine` | PostgreSQL database. Automatically runs `init.sql` on first start to create tables and insert seed data |
| `busybox` (init) | `busybox:1.36` | Temporary init container inside the backend pod. Waits until PostgreSQL port 5432 is open before letting the backend start |

---

## 3. Kubernetes objects

| Kind | Name | Description |
|---|---|---|
| `Namespace` | `vigimeteo` | Isolates all objects of this application from the rest of the cluster |
| `PersistentVolume` | `vigimeteo-db-pv` | 1 Gi storage volume mapped to `~/vigimeteo-db-data` on the host node |
| `PersistentVolumeClaim` | `vigimeteo-db-pvc` | Request for storage, bound to the PV above. Used by the StatefulSet |
| `ConfigMap` | `vigimeteo-db-init` | Holds the SQL init script (`init.sql`). Mounted into the PostgreSQL container |
| `StatefulSet` | `vigimeteo-db` | Manages the PostgreSQL pod. Provides a stable name and stable storage |
| `Deployment` | `vigimeteo-backend` | Manages 2 replicas of the Vert.x backend |
| `Deployment` | `vigimeteo-frontend` | Manages 2 replicas of the Nginx/React frontend |
| `Service` (Headless) | `vigimeteo-db` | Gives the PostgreSQL pod a stable DNS name: `vigimeteo-db.vigimeteo.svc.cluster.local` |
| `Service` (NodePort) | `vigimeteo-backend-service` | Exposes the backend API on port **30888** (accessible from the host) |
| `Service` (NodePort) | `vigimeteo-frontend-service` | Exposes the frontend on port **30500** (accessible from the host) |

---

## 4. Networks and volumes

### Network
Kubernetes creates a virtual internal network for the `vigimeteo` namespace automatically.  
- Pods communicate internally using **DNS service names** (e.g. `vigimeteo-db.vigimeteo.svc.cluster.local`).
- The frontend and backend are exposed externally via **NodePort** services.

| Access | Address |
|---|---|
| Frontend (browser) | `http://localhost:30500` |
| Backend API | `http://localhost:30888` |
| Database (internal only) | `vigimeteo-db.vigimeteo.svc.cluster.local:5432` |

### Volume
| Name | Type | Host path | Used by |
|---|---|---|---|
| `vigimeteo-db-pv` | PersistentVolume (hostPath) | `~/vigimeteo-db-data` | PostgreSQL StatefulSet |

The volume is created by `prepare-app.sh` with `mkdir -p ~/vigimeteo-db-data`.  
It persists data even after the application is stopped.

---

## 5. Container configuration

### Backend – environment variables

The backend connects to the database using these environment variables set in `deployment.yaml`:

| Variable | Value |
|---|---|
| `DB_HOST` | `vigimeteo-db.vigimeteo.svc.cluster.local` |
| `DB_PORT` | `5432` |
| `DB_NAME` | `postgres` |
| `DB_USER` | `postgres` |
| `DB_PASSWORD` | `admin` |

### Backend – init container

To avoid connection errors on startup, a `busybox` init container runs first and waits until PostgreSQL accepts connections on port 5432:

```bash
until nc -z vigimeteo-db.vigimeteo.svc.cluster.local 5432; do sleep 3; done
```

### Database – init script

The ConfigMap `vigimeteo-db-init` contains `init.sql` and is mounted into `/docker-entrypoint-initdb.d/` inside the PostgreSQL container. PostgreSQL automatically runs all `.sql` files in that folder on first startup.

### Images

Both images are built locally with `imagePullPolicy: IfNotPresent` so Kubernetes never tries to pull them from a registry.

---

## 6. How to run the application

### Prerequisites
- `docker` installed and running
- `kubectl` configured and connected to a cluster
- For **Minikube**: run `eval $(minikube docker-env)` first so images are built inside Minikube's daemon

### Step 1 – Prepare (first time only)

```bash
bash prepare-app.sh
```

This creates the PV host directory and builds the two Docker images.

### Step 2 – Start

```bash
bash start-app.sh
```

Applies all Kubernetes objects in the correct order and waits for PostgreSQL to be ready before deploying the backend.

### Step 3 – Pause / restart

There is no "pause" in Kubernetes. To stop traffic you can scale down replicas:

```bash
kubectl scale deployment vigimeteo-backend vigimeteo-frontend --replicas=0 -n vigimeteo
```

To restart:

```bash
kubectl scale deployment vigimeteo-backend vigimeteo-frontend --replicas=2 -n vigimeteo
```

### Step 4 – Delete

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

This deletes the namespace (which removes all objects inside it) and the PersistentVolume.  
The data folder `~/vigimeteo-db-data` is **not** deleted. To fully clean up:

```bash
rm -rf ~/vigimeteo-db-data
```

---

## 7. How to access the application

Once the app is started, open your browser at:

**http://localhost:30500**

### Test credentials

| Role | Email | Password |
|---|---|---|
| Admin | `admin@a.com` | `azertyuiop` |
| Complexe user | `complexe@gmail.com` | `azertyuiop` |
| Regular user | `user@gmail.com` | `azertyuiop` |

### Verify everything is running

```bash
kubectl get all -n vigimeteo
```

All pods should show `1/1 Running`.

---

## Troubleshooting

**Pod stays `Pending`** → The PVC is not bound. Run `kubectl describe pod -n vigimeteo <pod-name>` and check the events. Make sure `~/vigimeteo-db-data` exists.

**Backend `CrashLoopBackOff`** → Check logs with `kubectl logs -n vigimeteo deployment/vigimeteo-backend`. Usually a DB connection issue.

**Images not found** → For Minikube, run `eval $(minikube docker-env)` before `prepare-app.sh`.