Install Poetry with pipx

[br3ndonland]

Description

Poetry has introduced some breaking changes recently. To help buffer against these breaking changes, and to promote reproducible Poetry installations, this PR will install Poetry with pipx instead of get-poetry.py.

Changes

GitHub Actions

The following steps will be taken to install Poetry and verify that the correct version is installed:

1. Set the PIPX_VERSION and POETRY_VERSION environment variables, which will be used to install specific versions of each package.
2. Set the POETRY_VIRTUALENVS_IN_PROJECT=true environment variable so that Poetry uses a consistent path for the project's virtualenv.
3. Install pipx with pip, for the appropriate version of Python. pipx is included by default in the GitHub Actions virtual environment, but only for the default Python version, not necessarily the version installed by actions/setup-python.
4. Install Poetry with pipx, instead of the get-poetry.py and install-poetry.py install scripts.
5. Install the Poetry project with poetry install as usual.
6. Test that the Poetry version returned by the poetry -V command matches $POETRY_VERSION.
7. Test that the project's virtualenv is installed into the expected location.

These steps promote reproducible Poetry installations.

Docker

As explained in python-poetry/poetry#1879 (comment), there are two conflicting conventions to consider when working with Poetry in Docker:

1. Docker's convention is to not use virtualenvs, because containers themselves provide sufficient isolation.
2. Poetry's convention is to always use virtualenvs, because of the reasons given in #2822 Add dockerfile install instructions python-poetry/poetry#3209 (comment).

This project previously preferred the Docker convention:

• Poetry itself was installed with the get-poetry.py script, with the environment variable POETRY_HOME=/opt/poetry used to specify a consistent location for Poetry.
• poetry install was used with POETRY_VIRTUALENVS_CREATE=false to install the project's packages into the system Python directory.

The conventional Docker approach no longer works because:

• The old install script get-poetry.py is deprecated and not compatible with Python 3.10.
• The new install script install-poetry.py has been problematic so far, and Poetry doesn't really test it, so it will likely continue to be problematic.

In the updated approach:

• ENV PATH=/opt/pipx/bin:/app/.venv/bin:$PATH will be set first to prepare the $PATH.
• pip will be used to install a pinned version of pipx.
• pipx will be used to install a pinned version of Poetry, with PIPX_BIN_DIR=/opt/pipx/bin used to specify the location where pipx installs the Poetry command-line application, and PIPX_HOME=/opt/pipx/home used to specify the location for pipx itself.
• poetry install will be used with POETRY_VIRTUALENVS_CREATE=true, POETRY_VIRTUALENVS_IN_PROJECT=true and WORKDIR /app to install the project's packages into the virtualenv at /app/.venv.

Subsequent python commands will use the executable at app/.venv/bin/python. As long as POETRY_VIRTUALENVS_IN_PROJECT=true and WORKDIR /app are retained, subsequent Poetry commands will use the same virtual environment at /app/.venv.

For a Poetry project with the following directory structure:

• repo/
  • package/
    • __init__.py
    • main.py
  • Dockerfile
  • poetry.lock
  • pyproject.toml

A minimal Dockerfile could look like this:

ARG PYTHON_VERSION=3.10
FROM python:$PYTHON_VERSION
ARG PIPX_VERSION=0.16.4 POETRY_VERSION=1.1.11
ENV PATH=/opt/pipx/bin:/app/.venv/bin:$PATH PIPX_BIN_DIR=/opt/pipx/bin PIPX_HOME=/opt/pipx/home POETRY_VIRTUALENVS_IN_PROJECT=true
COPY poetry.lock pyproject.toml /app/
WORKDIR /app
RUN python -m pip install --no-cache-dir --upgrade pip "pipx==$PIPX_VERSION" && \
  pipx install "poetry==$POETRY_VERSION" && \
  poetry install --no-dev --no-interaction --no-root
COPY package /app/package
ENTRYPOINT ["python"]
CMD ["-m", "package.main"]

Related

• Pin and test Poetry version fastenv#6
• Add Python 3.10 support #36
• Pin and test Poetry version #44
• Document docker poetry best practices python-poetry/poetry#1879 (comment)
• Consider strictly following SemVer python-poetry/poetry#4271
• Huge number of bugs for a patch release version 1.1.8 - reconsider how releases are versioned python-poetry/poetry#4429

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/br3ndonland/inboard/8WLzDUrKnkT4YY5rVWJynKMDBnEV
✅ Preview: https://inboard-git-pipx-poetry-br3ndonland.vercel.app

[codecov]

Codecov Report

Merging #47 (ebd8454) into develop (48ae350) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           develop       #47   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           10        10           
  Lines          264       264           
=========================================
  Hits           264       264           

Flag	Coverage Δ
unit	100.00% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 48ae350...ebd8454. Read the comment docs.