Derive Poetry Lock from

poetry_to_pyproject.py

import tomlkit

LOCK_FILE_PATH = "poetry.lock"
PYPROJECT_PATH = "pyproject.toml"


def main():
    try:
        with open(LOCK_FILE_PATH, "r") as lock_file:
            lock_content = lock_file.read()
    except FileNotFoundError:
        raise AssertionError("Could not find the poetry.lock file.")

    lock_data = tomlkit.parse(lock_content)

    package_data = lock_data.get("package", [])

    if not package_data:
        raise AssertionError("No package data found in the poetry.lock file.")

    doc = tomlkit.document()

    tool_table = tomlkit.table()
    doc.add("tool", tool_table)

    poetry_table = tomlkit.table()
    tool_table.add("poetry", poetry_table)

    poetry_table.add("name", "app")
    poetry_table.add("version", "0.0.0")
    poetry_table.add("description", "")
    poetry_table.add("authors", [])

    dependencies_table = tomlkit.table()
    poetry_table.add("dependencies", dependencies_table)

    dependencies_table.add("python", "^3")

    all_dependencies = set()
    for package in package_data:
        dependencies = package.get("dependencies", {})
        all_dependencies.update(dependencies.keys())

    top_level_packages = [
        package for package in package_data if package["name"] not in all_dependencies]

    for package in top_level_packages:
        name = package["name"]
        version = package["version"]
        dependencies_table.add(name, f"^{version}")

    with open(PYPROJECT_PATH, "w") as pyproject_file:
        pyproject_file.write(tomlkit.dumps(doc))


if __name__ == "__main__":
    main()

This is great! Have you thought about creating a Poetry plugin?

• create a temporary directory
• copy poetry.lock into it
• create a minimal pyproject.toml using this script
• run poetry install --no-root in the directory

This would allow you to avoid bundling poetry_to_pyproject.py as part of your Dockerfile:

COPY poetry_to_pyproject.py poetry.lock ./
RUN python poetry_to_pyproject.py
RUN poetry install

would become:

RUN \
    --mount=type=bind,source=poetry.lock,target=/workspace/poetry.lock \
    poetry self add poetry-plugin-lock-install \
    && poetry lock-install

This might not be the exact way to do it, but hopefully you can see what I am saying?