# Docker Setup for RDC Simulation

This guide explains how to run the RDC Simulation environment inside a Docker container with NVIDIA GPU support and X11 display forwarding. This approach isolates the simulation environment from your host system while providing full hardware acceleration.

## Prerequisites

1.  **Docker Engine**: Install Docker for your OS.
2.  **NVIDIA GPU & Drivers**: Ensure you have an NVIDIA GPU and proprietary drivers installed.
3.  **NVIDIA Container Toolkit**: Required for GPU pass-through to Docker.

    ```bash
    # Install NVIDIA Container Toolkit
    curl -fsSL https://nvidia.github.io/libnvidia-container/gpgkey | sudo gpg --dearmor -o /usr/share/keyrings/nvidia-container-toolkit-keyring.gpg
    echo "deb [signed-by=/usr/share/keyrings/nvidia-container-toolkit-keyring.gpg] https://nvidia.github.io/libnvidia-container/stable/deb/$(. /etc/os-release;echo $ID$VERSION_ID) /" | sudo tee /etc/apt/sources.list.d/nvidia-container-toolkit.list
    sudo apt update && sudo apt install -y nvidia-container-toolkit
    sudo systemctl restart docker
    ```

## Quick Start

### 1. Build the Image

```bash
cd ~/RDC_Simulation
docker compose build
```
*This may take 15-20 minutes mostly due to compiling Gazebo plugins.*

### 2. Allow X11 Display Access

To allow the container to display the Gazebo GUI on your host screen:

```bash
xhost +local:docker
```

### 3. Run the Container

```bash
docker compose run --rm simulation
```

This drops you into a bash shell inside the container as the user `pilot`.

---

## Running the Simulation

Once inside the container, the environment is pre-configured.

### 1. Start the Environment
You can use the helper script to verify everything is ready:

```bash
./docker-entrypoint.sh
```

### 2. Launch Components (Multi-Terminal)

Since `docker compose run` gives you a single terminal, you can verify basic functionality, but for the full workflow you might want to run the combined script:

```bash
# Run everything (Gazebo + SITL + Controller)
./scripts/run_ardupilot_controller.sh
```

**Or** manually launch components in background/separate terminals:

To open a second terminal into the *running* container:
1.  Find the container name or ID: `docker ps`
2.  Exec into it: `docker exec -it <container_name> bash`

Then run your components:
*   **Terminal 1:** Gazebo
    ```bash
    ./scripts/run_ardupilot_sim.sh runway
    ```
*   **Terminal 2:** ArduPilot SITL
    ```bash
    sim_vehicle.py -v ArduCopter -f gazebo-iris --model JSON --console
    ```
*   **Terminal 3:** Controller
    ```bash
    python scripts/run_ardupilot.py --pattern square
    ```

---

## Video Recording

The Docker image includes `ffmpeg` and tools to record the simulation.

### Record Flight
Run a flight pattern and save the video automatically:

```bash
python scripts/record_flight.py --pattern square --quality high --output my_flight_video
```
Videos are saved to the `recordings/` directory which is mounted inside the container (if you used a volume mount) or can be copied out.

### Record Manually
```bash
./scripts/record_simulation.sh --duration 30
```

---

## Headless Mode (CI/Server)

If you are running on a remote server without a display attached, use the headless service. Note that standard Gazebo GUI will not show, but you can still run simulations and record videos (rendering offscreen).

```bash
docker compose run --rm simulation-headless
```

## Troubleshooting

**"All CUDA-capable devices are busy or unavailable"**
Check your NVIDIA drivers on the host. verifying with `nvidia-smi`.

**"Example: Could not connect to display :0"**
Make sure you ran `xhost +local:docker` on the host machine.
If using SSH, ensure X11 forwarding is enabled (`ssh -X`).

**Persisting Data**
The `docker-compose.yml` mounts the project directory. Changes to python scripts *inside* the container are reflected on your host machine.