reduce production image size without runtime drift

backend/Dockerfile

@@ -1,8 +1,7 @@
-# Stage 1: Build stage with dependencies
 ARG PYTHON_IMAGE=python:3.13-slim
+
 FROM ${PYTHON_IMAGE} AS builder
 
-# Metadata labels
 LABEL maintainer="Voyage contributors" \
       version="0.10.0" \
       description="Voyage — the ultimate self-hosted travel companion." \
@@ -14,64 +13,55 @@ LABEL maintainer="Voyage contributors" \
       org.opencontainers.image.vendor="Voyage contributors" \
       org.opencontainers.image.licenses="GPL-3.0"
 
-ENV PYTHONDONTWRITEBYTECODE=1
-ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    DEBIAN_FRONTEND=noninteractive \
+    VIRTUAL_ENV=/opt/venv
+
 WORKDIR /code
-ENV DEBIAN_FRONTEND=noninteractive
 
-# Install system dependencies needed for build
 RUN apt-get update && apt-get install -y --no-install-recommends \
-      git \
-      postgresql-client \
-      gdal-bin \
+      build-essential \
       libgdal-dev \
-      nginx \
-      memcached \
-      supervisor \
-    && apt-get clean && rm -rf /var/lib/apt/lists/*
+      libpq-dev \
+    && rm -rf /var/lib/apt/lists/*
 
-# Install Python dependencies
-COPY ./server/requirements.txt /code/
-RUN pip install --upgrade pip \
-    && pip install --no-cache-dir -r requirements.txt
+COPY ./server/requirements.txt /tmp/requirements.txt
+
+RUN python -m venv "$VIRTUAL_ENV" \
+    && "$VIRTUAL_ENV/bin/pip" install --upgrade pip \
+    && "$VIRTUAL_ENV/bin/pip" install --no-cache-dir --no-compile --prefer-binary -r /tmp/requirements.txt \
+    && find "$VIRTUAL_ENV" \( -type d -name '__pycache__' -o -type d -name 'tests' \) -prune -exec rm -rf '{}' + \
+    && find "$VIRTUAL_ENV" -type f \( -name '*.pyc' -o -name '*.pyo' \) -delete
 
-# Stage 2: Final image with runtime dependencies
 FROM ${PYTHON_IMAGE}
-WORKDIR /code
-ENV PYTHONDONTWRITEBYTECODE=1
-ENV PYTHONUNBUFFERED=1
-ENV DEBIAN_FRONTEND=noninteractive
 
-# Install runtime dependencies (including GDAL)
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    DEBIAN_FRONTEND=noninteractive \
+    VIRTUAL_ENV=/opt/venv
+
+WORKDIR /code
+
 RUN apt-get update && apt-get install -y --no-install-recommends \
-      postgresql-client \
-      gdal-bin \
-      libgdal-dev \
+      libgdal36 \
       nginx \
       memcached \
       supervisor \
-    && apt-get clean && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/*
 
-# Copy Python packages from builder
-COPY --from=builder /usr/local/lib/python3.13/site-packages /usr/local/lib/python3.13/site-packages
-COPY --from=builder /usr/local/bin /usr/local/bin
-
-# Copy project code and configs
+COPY --from=builder /opt/venv /opt/venv
 COPY ./server /code/
 COPY ./nginx.conf /etc/nginx/nginx.conf
 COPY ./supervisord.conf /etc/supervisor/conf.d/supervisord.conf
 COPY ./entrypoint.sh /code/entrypoint.sh
+
 RUN chmod +x /code/entrypoint.sh \
     && mkdir -p /code/static /code/media
 
-# Collect static files
-RUN python3 manage.py collectstatic --noinput --verbosity 2
+RUN "$VIRTUAL_ENV/bin/python" manage.py collectstatic --noinput --verbosity 2
 
-# Expose ports
 EXPOSE 80 8000
 
-# Start with an entrypoint that runs init tasks then starts supervisord
 ENTRYPOINT ["/code/entrypoint.sh"]
-
-# Start supervisord to manage processes
 CMD ["supervisord", "-c", "/etc/supervisor/conf.d/supervisord.conf"]