fastAPI Poetry Docker image

Dockerfile

FROM python:3.9-slim AS install
RUN apt-get update \
    && apt-get upgrade -y \
    && apt-get install -y --no-install-recommends curl \
    && apt-get autoremove -y
RUN pip install --upgrade pip
WORKDIR /app/
# install poetry and keep the get-poetry script so it can be reused later.
ENV POETRY_HOME="/opt/poetry"
RUN curl https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py > get-poetry.py
RUN python get-poetry.py

FROM install AS app-image
# support multiple apps as generic arguments
ARG APP_TARGET
# allow controlling the poetry installation of dependencies via external args
ARG INSTALL_ARGS="--no-root --no-dev"
# pass ENVIRONMENT from outside, e.g. development / staging / production
ARG ENVIRONMENT="production"
WORKDIR /app/
# let poetry know where its installed and add the poetry bin to the path
ENV POETRY_HOME="/opt/poetry"
ENV PATH="$POETRY_HOME/bin:$PATH"
ENV ENVIRONMENT=$ENVIRONMENT
COPY $APP_TARGET/pyproject.toml $APP_TARGET/poetry.lock ./
COPY $APP_TARGET/app app
# install without virtualenv, since we are inside a continer, follow by cleanup
RUN poetry config virtualenvs.create false \
    && poetry install $INSTALL_ARGS \
    && python get-poetry.py --uninstall \
    && rm get-poetry.py
# cleanup curl and apt cache
RUN apt-get purge -y curl \
    && apt-get clean -y \
    && rm -rf /root/.cache \
    && rm -rf /var/apt/lists/* \
    && rm -rf /var/cache/apt/*
# switch to a non-root user for security
RUN addgroup --system --gid 1001 "$APP_TARGET-user"
RUN adduser --system --uid 1001 "$APP_TARGET-user"
USER "$APP_TARGET-user"

This docker file is setup for a monorepo scenario. The assumption that there are multiple apps, each in its own python package, which follow have source code inside <package_folder>/app. Hence the $APP_TARGET build argument. This can of course be modified as needed.