Update Dockerfile

Dockerfile

@@ -1,28 +1,51 @@
-# Dockerfile (Place in the root of your repo)
+# Dockerfile
 
-# Use a specific Python version slim image for smaller size
-# Or a version compatible with your dependencies
+# Use a specific Python version slim image for smaller size.
+# python:3.10 is recommended as it's well-supported by many ML libraries.
 FROM python:3.10-slim
 
+# Set the working directory inside the container
 WORKDIR /code
 
-# Install system dependencies (like ffmpeg for imageio's mp4 writing)
-# Using --no-install-recommends helps keep the image smaller
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    ffmpeg \
-    && apt-get clean && rm -rf /var/lib/apt/lists/* # Clean up apt cache
+# Set Hugging Face cache directory environment variable.
+# Use /tmp which is generally writable in containers and suitable for caching downloads.
+# This prevents permission errors when transformers/diffusers try to download models.
+ENV HUGGINGFACE_HUB_CACHE="/tmp/huggingface_cache"
+# Optional: You could also set HF_HOME for broader config/cache, but HUB_CACHE is specific to downloads.
+# ENV HF_HOME="/tmp/hf_home"
 
+# Optional: Explicitly create the directory and ensure permissions, though /tmp usually works.
+# RUN mkdir -p $HUGGINGFACE_HUB_CACHE && chmod 777 $HUGGINGFACE_HUB_CACHE
+
+# Install essential system dependencies.
+# - ffmpeg: Required by imageio for writing MP4 video files.
+# Use --no-install-recommends to keep the image smaller.
+# Clean up apt cache afterwards in the SAME layer to reduce image size.
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+        ffmpeg \
+    && apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
+
+# Copy just the requirements file first to leverage Docker cache.
+# If requirements.txt doesn't change, this layer won't be rebuilt.
 COPY requirements.txt requirements.txt
-# Use --no-cache-dir during pip install to reduce layer size
+
+# Install Python dependencies using pip.
+# Upgrade pip first.
+# Use --no-cache-dir to reduce image size by not storing the pip download cache.
 RUN pip install --no-cache-dir --upgrade pip && \
     pip install --no-cache-dir -r requirements.txt
 
+# Copy the rest of the application code into the container's working directory
 COPY . /code
 
-# Expose the port FastAPI will run on (default 8000 for uvicorn, 7860 common for HF)
+# Expose the port the application will run on.
+# 7860 is the default port expected by Hugging Face Spaces Gradio/Docker SDKs.
 EXPOSE 7860
 
-# Command to run the application using uvicorn
-# Use --host 0.0.0.0 to make it accessible from outside the container
-# Use --port 7860 as expected by HF Spaces default proxying
+# Define the command to run the application when the container starts.
+# Use uvicorn to run the FastAPI app defined in app.py (the 'app' object).
+# --host 0.0.0.0 makes the server accessible from outside the container.
+# --port 7860 matches the EXPOSE directive.
 CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--port", "7860"]