add .env.example and update README for environment variable configuration

README.md

@@ -26,7 +26,7 @@ tesla-cam-view-1/
 ## Requirements
 
 - Python 3.x
-- Flask (see `requirements.txt`)
+- Flask, python-dotenv, gunicorn (see `requirements.txt`)
 
 ## Setup
 
@@ -46,17 +46,27 @@ tesla-cam-view-1/
    pip install -r requirements.txt
    ```
 
-3. Configure the TeslaCam directory by editing `TESLACAM_DIRECTORY` in `videoplayer.py`:
+3. Configure the TeslaCam directory via environment variables. Copy the example
+   file and edit it:
 
-   ```python
-   TESLACAM_DIRECTORY = r'W:\2026\USA2026\TeslaCam'
+   ```bash
+   cp .env.example .env
    ```
 
-   Point this to the root folder containing your `RecentClips`, `SavedClips`, and `SentryClips` subfolders.
+   ```ini
+   TESLACAM_DIRECTORY=/mnt/TeslaCam
+   FLASK_RUN_HOST=0.0.0.0
+   FLASK_RUN_PORT=5000
+   FLASK_DEBUG=0
+   ```
+
+   `TESLACAM_DIRECTORY` should point to the root folder containing your
+   `RecentClips`, `SavedClips`, and `SentryClips` subfolders. Variables set in
+   the real environment take precedence over `.env`.
 
 ## Usage
 
-Run the app:
+### Local development server
 
 ```bash
 python videoplayer.py
@@ -64,6 +74,26 @@ python videoplayer.py
 
 Then open [http://localhost:5000](http://localhost:5000) in your browser.
 
+### Production (WSGI server on Linux)
+
+For production, run the app behind a WSGI server such as **gunicorn**. The
+`app` object in `videoplayer.py` is the WSGI entry point:
+
+```bash
+gunicorn -w 4 -b 0.0.0.0:5000 'videoplayer:app'
+```
+
+`TESLACAM_DIRECTORY` is read from the environment (or `.env`), so make sure it
+is set for the gunicorn process, e.g.:
+
+```bash
+export TESLACAM_DIRECTORY=/mnt/TeslaCam
+gunicorn -w 4 -b 0.0.0.0:5000 'videoplayer:app'
+```
+
+For a systemd service or other process manager, set the variable in the unit
+file / environment rather than relying on `.env`.
+
 - The **main page** lists all clips grouped by camera view with a player and searchable clip list.
 - Click a clip to play it; use the camera switch buttons to jump between angles for the same timestamp.
 - The `/camera/<view>` route shows all clips for a single camera.
@@ -89,6 +119,7 @@ Then open [http://localhost:5000](http://localhost:5000) in your browser.
 
 ## Notes
 
-- The app runs with `debug=True` by default — disable this for production use.
+- Debug mode is off by default (`FLASK_DEBUG=0`) and is only used by the local
+  dev server. It has no effect when running under a WSGI server like gunicorn.
 - The TeslaCam directory must be accessible from the machine running the app (e.g., a mounted USB drive or network share).
 - Filename parsing assumes the standard TeslaCam naming format; files not matching the regex are ignored.