Poetry not installing current project in docker build

[tom-whitehead]

Hi, need some help. I have a poetry project that runs well locally. When I do poetry install it installs the current project and I can import my files as an installed Python module (e.g from mymodule.dtos import MyObject, rather than than using a relative import). However, when I build a docker image and try to run it, I get a module not found error and it doesn't run.

This is my pyproject.toml:

[tool.poetry]
name = "my-project"
version = "0.1.0"
description = ""
readme = "README.md"
packages = [{include = "my_module"}]

[tool.poetry.dependencies]
python = "^3.13"
boto3 = "^1.35.78"
motor = "^3.6.0"
pymysql = "^1.1.1"
types-pymysql = "^1.1.0.20241103"
openai = "^1.57.4"
numpy = "^2.2.0"

[tool.poetry.group.dev.dependencies]
ruff = "^0.8.2"
mypy = "^1.13.0"

[build-system]
requires = ["poetry-core"]
build-backend = "poetry.core.masonry.api"

And this is my Docker file:

ROM public.ecr.aws/docker/library/python:3.13-slim

RUN apt-get update \
    && apt-get install -y curl build-essential \
    && rm -rf /var/lib/apt/lists/*

RUN curl -sSL https://install.python-poetry.org | python -
ENV PATH="/root/.local/bin:$PATH"

WORKDIR /app

COPY my-project/pyproject.toml my-project/poetry.lock ./

RUN poetry config virtualenvs.create false \
    && poetry install --without dev 

COPY my-project/* ./my-project/

CMD ["poetry", "run", "python", "my_module/app.py"]

Any help from someone with experience with using docker and Poetry would be much appreciated. Ideally I want to keep my module as an installed to make testing and CI easier down the line.

[CarlosCuevas]

i had to replace
COPY my-project/pyproject.toml my-project/poetry.lock ./
with
COPY . ./

[abn]

You need poetry install --no-root --without dev (install only locked deps) if you are not copying your source tree into the container for caching.

Then once that is complete and you copy over the source tree, run install again without the --no-root.

[tom-whitehead]

Thanks for responding guys. I actually got it working like this:

FROM public.ecr.aws/docker/library/python:3.11-slim

WORKDIR /app

RUN apt-get update \
    && apt-get install -y --no-install-recommends build-essential curl \
    && rm -rf /var/lib/apt/lists/*

RUN curl -sSL https://install.python-poetry.org | python - \
    && ln -s /root/.local/bin/poetry /usr/local/bin/poetry
ENV PATH="/root/.local/bin:$PATH"

COPY my-project/pyproject.toml my-project/poetry.lock ./
COPY my-project/my_module ./my_module

RUN poetry config virtualenvs.create false \
    && poetry install --without dev

CMD ["poetry", "run", "python", "my_module/app.py"]

So:

• moving the COPY above the RUN poetry.
• moving up the the WORKDIR
• I also had to remove reference of the readme from pyproject.toml otherwise the install fails as it's not in the container file system (alternatively could have copied it with pyproject.toml.

Mysteriously, if I don't separate out the two copy steps like that the install fails.

@abn What's the advantage of doing the install in two steps like that without the root and then for the root? I've seen people do this elsewhere too. -> EDIT: Ignore me sorry I didn't read your answer fully