# Small Business Inventory Management System

This is a FastAPI application for managing small business inventory, products, orders, and suppliers.

## Features

- User authentication and authorization
- Product management
- Inventory tracking
- Order processing
- Supplier management
- Category organization

## API Endpoints

- `/docs` - Swagger UI documentation
- `/redoc` - ReDoc documentation
- `/health` - Health check endpoint
- `/api/v1/auth` - Authentication endpoints
- `/api/v1/users` - User management
- `/api/v1/products` - Product management
- `/api/v1/inventory` - Inventory management
- `/api/v1/orders` - Order processing
- `/api/v1/suppliers` - Supplier management
- `/api/v1/categories` - Category management

## Running Locally

1. Install dependencies:
   ```
   pip install -r requirements.txt
   ```

2. Start the server:
   ```
   uvicorn main:app --host 0.0.0.0 --port 8000 --reload
   ```

## Environment Variables

The application uses the following environment variables:

- `SECRET_KEY`: Secret key for JWT token generation
- `SERVER_NAME`: Server name (e.g., "Inventory Management System")
- `SERVER_HOST`: Server host URL (e.g., "https://inventory.example.com")
- `FIRST_SUPERUSER`: Email for the first superuser
- `FIRST_SUPERUSER_PASSWORD`: Password for the first superuser

## Kubernetes Deployment

The application can be deployed using Kubernetes with the provided configuration files in the `kubernetes/` directory:

- `deployment.yaml`: Deployment configuration (using name `prod-pod`)
- `service.yaml`: Service configuration (using name `prod-pod-service`)
- `pvc.yaml`: Persistent Volume Claim for storage
- `secrets.yaml`: Secret configuration for environment variables

### Deployment Configuration

The deployment has been optimized for maximum scheduling flexibility and minimal resource requirements:

- **Minimal Resource Requirements**:
  - Single replica (no high availability) to ensure easier scheduling
  - Extremely low resource requests (10m CPU, 64Mi memory)
  - No resource limits to allow for flexible resource usage
  - Reduced PVC storage request (100Mi)
  - Optional emptyDir volume configuration (commented out)

- **Maximum Scheduling Flexibility**:
  - Uses Recreate deployment strategy instead of RollingUpdate
  - Tolerations for all taints using `operator: "Exists"`
  - No node selector or required affinity rules
  - Default scheduler and DNS policy

- **Vault Integration (Commented Out)**:
  - Added configuration templates for HashiCorp Vault integration
  - Instructions for using Vault Agent Injector with the deployment
  - Support for vault-agent and vault-agent-init sidecars

### Troubleshooting "pod does not have a host assigned" Error

If you encounter this error, follow these steps:

1. **Check Cluster Resources**:
   ```bash
   kubectl get nodes
   kubectl describe nodes
   ```
   - Ensure nodes have available CPU, memory, and are in Ready state

2. **Check PVC Status**:
   ```bash
   kubectl get pvc
   kubectl describe pvc inventory-api-pvc
   ```
   - If the PVC is stuck in Pending state, check storage class availability:
     ```bash
     kubectl get storageclass
     ```
   - If no storage class is available, modify deployment.yaml to use emptyDir:
     ```yaml
     volumes:
     - name: storage-volume
       emptyDir: {}
       # persistentVolumeClaim:
       #   claimName: inventory-api-pvc
     ```

3. **Check Pod Status**:
   ```bash
   kubectl get pods
   kubectl describe pod <pod-name>
   kubectl get events --sort-by='.metadata.creationTimestamp'
   ```
   - Look for scheduling errors or resource constraints

4. **Verify Vault Configuration** (if applicable):
   - If your cluster uses HashiCorp Vault, uncomment the Vault configuration in deployment.yaml
   - Check Vault service status:
     ```bash
     kubectl get svc -n vault
     ```

5. **Extreme Resource Reduction**:
   - If still having issues, you can uncomment and adjust these values in deployment.yaml:
     ```yaml
     resources:
       requests:
         cpu: "1m"  # Absolute minimum
         memory: "32Mi"  # Absolute minimum
     ```

### Deployment Commands

To deploy:

```bash
# Apply secret first
kubectl apply -f kubernetes/secrets.yaml

# Create PVC
kubectl apply -f kubernetes/pvc.yaml

# Apply deployment
kubectl apply -f kubernetes/deployment.yaml

# Apply service
kubectl apply -f kubernetes/service.yaml
```

To check status:

```bash
# Get pod status
kubectl get pods

# Describe pod for detailed information
kubectl describe pod <pod-name>

# Check recent events
kubectl get events --sort-by='.metadata.creationTimestamp'

# Get logs from container
kubectl logs <pod-name> -c app
```

To delete deployment:

```bash
kubectl delete -f kubernetes/deployment.yaml
kubectl delete -f kubernetes/service.yaml
kubectl delete -f kubernetes/pvc.yaml
kubectl delete -f kubernetes/secrets.yaml
```