meltano install not working inside a docker container

[seunggs]

I'm trying to run a very simple test run of Meltano (tap-csv -> target-s3) locally using docker.

I was able to get this working fine outside of it, but inside the container, it keeps throwing this error:

Cannot start plugin tap-csv: Executable 'tap-csv' could not be found. Extractor 'tap-csv' may not have been installed yet using 'meltano install extractor tap-csv', or the executable name may be incorrect.

Here's my Dockerfile (simplified):

FROM python:3.10-slim-bullseye as build
WORKDIR /app
ENV VENV=/venv

# Prepend poetry & venv to path
ENV PATH="/opt/poetry/bin:$VENV/bin:$PATH"

# Install poetry separate from system interpreter
RUN python3 -m venv $VENV \
    && $VENV/bin/pip install -U pip setuptools \
    && $VENV/bin/pip install poetry

# Install dependencies
# NOTE: --no-root instructs Poetry to avoid installing the current project into the virtual environment.
COPY pyproject.toml poetry.lock ./
RUN poetry install --no-dev --no-root

# Copy the rest of the project files
COPY ./test-project ./test-project

# Run meltano install since .meltano is not copied over (must be run inside meltano dir)
WORKDIR /app/test-project/meltano-dir
RUN meltano install

# PRODUCTION
FROM python:3.10-slim-bullseye as production

ENV VENV=/venv

# Set working directory
WORKDIR /app

# Prepend venv to path
ENV PATH="$VENV/bin:$PATH"

# Copy built venv and project files
COPY --from=build $VENV $VENV
COPY --from=build /app/test-project /app/test-project

ENTRYPOINT bash

[seunggs]

I'm not sure exactly how meltano install works, but turns out I need to run it in the production stage, not the build stage. Copying the venv and project files after running meltano install is not enough.