Dockerfile

# Library API (FastAPI). Two stages: install the packages into a virtual environment,
# then copy only that environment and the source into a clean slim image.
#   docker build -t library-api-fastapi .
#   docker compose up --build            (the app with PostgreSQL 17)

FROM python:3.13-slim AS build
ENV PIP_NO_CACHE_DIR=1 PIP_DISABLE_PIP_VERSION_CHECK=1
RUN python -m venv /opt/venv
ENV PATH=/opt/venv/bin:$PATH
COPY requirements.txt .
RUN pip install -r requirements.txt

FROM python:3.13-slim
# HOST=0.0.0.0 so the server is reachable from outside the container.
# Time zone data for Europe/London comes from the tzdata package in requirements.txt.
ENV PATH=/opt/venv/bin:$PATH \
    PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    HOST=0.0.0.0 \
    PORT=8000 \
    TZ=Europe/London
RUN useradd --create-home --uid 10001 library
WORKDIR /srv/library
COPY --from=build /opt/venv /opt/venv
COPY alembic.ini ./
COPY alembic ./alembic
COPY app ./app
# The default DATABASE_URL (sqlite:///library.db) writes here, so the app user owns the folder.
RUN chown library:library /srv/library
USER library
EXPOSE 8000
# Runs the migrations and loads the sample data on an empty database, then serves.
CMD ["python", "-m", "app"]