Using pipenv and Docker#

I had a Django project that used pipenv (in particular a Pipfile.lock) to manage dependencies and I wanted to build a Docker container for it.

With the help of this article (for the PIPENV_VENV_IN_PROJECT tip) I came up with the following:

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FROM python:3.6.15-slim-buster
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RUN mkdir -p /app
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WORKDIR /app
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COPY . .
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ENV PIPENV_VENV_IN_PROJECT=1
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RUN pip install pipenv
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RUN pipenv sync
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RUN pipenv run ./manage.py collectstatic --noinput
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EXPOSE 8000
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CMD pipenv run gunicorn --bind 0.0.0.0:8000 --timeout 120 --workers 2 cbwg.wsgi

Ignore the base image - the project was an emergency port from Heroku and I didn’t have time to upgrade it from the ancient version of Python it was using (if you’re using a Pipfile.lock file you need to keep your Python version stable unless you want to lock new versions).

The key lines here are these ones:

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RUN mkdir -p /app
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WORKDIR /app
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COPY . .
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ENV PIPENV_VENV_IN_PROJECT=1
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RUN pip install pipenv
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RUN pipenv sync

First we create a /app directory and set that as the working directory.

COPY . . copies ALL files and directories from the Dockerfile directory into the new image, inside /app.

ENV PIPENV_VENV_IN_PROJECT=1 is important: it causes the resuling virtual environment to be created as /app/.venv. Without this the environment gets created somewhere surprising, such as /root/.local/share/virtualenvs/app-4PlAip0Q - which makes it much harder to write automation scripts later on.

Then we install pipenv and use RUN pipenv sync to install all of the package versions from our Pipfile.lock file (which was added by COPY . .).

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FROM python:3.6.15-slim-buster
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RUN mkdir -p /app
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WORKDIR /app
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COPY . .
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RUN pip install pipenv
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RUN pipenv sync --system
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RUN ./manage.py collectstatic --noinput
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EXPOSE 8000
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CMD pipenv run gunicorn --bind 0.0.0.0:8000 --timeout 120 --workers 2 cbwg.wsgi