fix: use Python 3.12 (Ubuntu 24.04 default), simplify Dockerfile, combine install steps

Dockerfile

@@ -1,48 +1,34 @@
 # Hugging Face Spaces Dockerfile for PaddleOCR-VL Document Parser API
 # GPU-accelerated document parsing with PaddleOCR-VL-1.5 + PaddlePaddle
-# Build: v5.0.0 - PaddleOCR-VL for high-quality OCR on Nvidia T4
+# Build: v5.0.0 - PaddleOCR-VL for high-quality OCR on Nvidia L4/T4
 #
 # NOTE: Run with --shm-size 16g for PaddlePaddle shared memory:
 #   docker build -t hf-docling .
 #   docker run --gpus all --shm-size 16g -p 7860:7860 -e API_TOKEN=test hf-docling
 
-# CUDA 12.6 runtime with cuDNN (required by PaddlePaddle GPU)
 FROM nvidia/cuda:12.6.3-cudnn-runtime-ubuntu24.04
 
 USER root
 
-RUN echo "========== BUILD STARTED at $(date -u '+%Y-%m-%d %H:%M:%S UTC') =========="
-
-# Install system dependencies
-RUN echo "========== STEP 1: Installing system dependencies ==========" && \
-    apt-get update && apt-get install -y --no-install-recommends \
-    # Python 3.11
-    python3.11 \
-    python3.11-venv \
-    python3.11-dev \
+# Install system dependencies (Python 3.12 is default in Ubuntu 24.04)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    python3 \
     python3-pip \
-    # Fonts for document rendering
+    python3-venv \
+    python3-dev \
     fonts-noto-core \
     fonts-noto-cjk \
     fontconfig \
-    # Image processing (required by OpenCV)
     libgl1 \
     libglib2.0-0 \
-    # PDF utilities (required by pdf2image)
     poppler-utils \
-    # Health checks
     curl \
-    && fc-cache -fv && \
-    # Set python3.11 as default python3/python
-    update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.11 1 && \
-    update-alternatives --install /usr/bin/python python /usr/bin/python3.11 1 && \
-    rm -rf /var/lib/apt/lists/* && \
-    echo "========== System dependencies installed =========="
+    && fc-cache -fv \
+    && rm -rf /var/lib/apt/lists/*
 
-# Create non-root user for HF Spaces (required by HuggingFace)
+# Create non-root user for HF Spaces
 RUN useradd -m -u 1000 user
 
-# Set environment variables
 ENV PYTHONUNBUFFERED=1 \
     PYTHONDONTWRITEBYTECODE=1 \
     IMAGES_SCALE=2.0 \
@@ -52,52 +38,26 @@ ENV PYTHONUNBUFFERED=1 \
     HOME=/home/user \
     PATH=/home/user/.local/bin:/usr/local/bin:/usr/bin:$PATH
 
-# Create cache directories with correct ownership
-RUN echo "========== STEP 2: Creating cache directories ==========" && \
-    mkdir -p /home/user/.cache/huggingface \
-    /home/user/.cache/paddleocr \
-    /home/user/app && \
-    chown -R user:user /home/user && \
-    echo "========== Cache directories created =========="
+RUN mkdir -p /home/user/.cache/huggingface /home/user/.cache/paddleocr /home/user/app \
+    && chown -R user:user /home/user
 
-# Switch to non-root user
 USER user
 WORKDIR /home/user/app
 
-# Copy requirements first for better caching
 COPY --chown=user:user requirements.txt .
 
-# Install PaddlePaddle GPU (must be installed before paddleocr)
-RUN echo "========== STEP 3: Installing PaddlePaddle GPU ==========" && \
-    python -m pip install --user --upgrade pip && \
-    python -m pip install --user paddlepaddle-gpu==3.2.1 -i https://www.paddlepaddle.org.cn/packages/stable/cu126/ && \
-    echo "========== PaddlePaddle GPU installed (verified at runtime) =========="
-
-# Install Python dependencies from requirements.txt
-RUN echo "========== STEP 4: Installing Python dependencies ==========" && \
-    python -m pip install --user -r requirements.txt && \
-    echo "Installed packages:" && \
-    pip list --user && \
-    echo "========== Python dependencies installed =========="
-
-# NOTE: Model pre-download skipped — PaddlePaddle GPU requires CUDA at import time,
-# which is unavailable during Docker build. Model downloads on first startup (~60s).
-RUN echo "========== STEP 5: Skipping model pre-download (no GPU during build) =========="
+# Install PaddlePaddle GPU then Python deps
+RUN python3 -m pip install --user --upgrade pip --break-system-packages && \
+    python3 -m pip install --user --break-system-packages paddlepaddle-gpu==3.2.1 -i https://www.paddlepaddle.org.cn/packages/stable/cu126/ && \
+    python3 -m pip install --user --break-system-packages -r requirements.txt
 
-# Copy application code
 COPY --chown=user:user . .
 
-RUN echo "========== STEP 6: Finalizing build ==========" && \
-    chmod +x start.sh && \
-    echo "Files in app directory:" && ls -la /home/user/app/ && \
-    echo "========== BUILD COMPLETED at $(date -u '+%Y-%m-%d %H:%M:%S UTC') =========="
+RUN chmod +x start.sh
 
-# Expose the port (HF Spaces standard)
 EXPOSE 7860
 
-# Health check
 HEALTHCHECK --interval=30s --timeout=30s --start-period=300s --retries=5 \
     CMD curl -f http://localhost:7860/ || exit 1
 
-# Single-process FastAPI app (no vLLM sidecar needed)
 CMD ["/bin/bash", "/home/user/app/start.sh"]