Generate Dockerfile from current Python environment

gendockerfile.py

import imp
import os.path
import sys
import types
import platform

__dockerfile_template__ = """
FROM ubuntu:latest

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update && apt-get -y update
RUN apt-get install -y build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python-openssl git

RUN useradd -m python_user
WORKDIR /home/python_user
USER python_user

RUN git clone https://github.com/pyenv/pyenv.git .pyenv
ENV HOME /home/python_user
ENV PYENV_ROOT $HOME/.pyenv
ENV PATH $PYENV_ROOT/shims:$PYENV_ROOT/bin:$PATH
RUN pyenv update && \
    pyenv install {version} && \
    pyenv global {version}
RUN pip install jupyter
RUN pip install {modules}
"""

def is_external_module(module_name):
    python_path = os.path.dirname(sys.executable)

    module_path = imp.find_module(module_name)
    return module_path[1] != None and 'site-packages' in module_path[1]

def external_imports():    
    names = set()
    for name, val in globals().copy().items():
        if isinstance(val, types.ModuleType) and is_external_module(val.__name__):
            names.add(val.__name__)
    return names

def generate_dockerfile_from_current_environment():
    version = platform.python_version()
    modules = ' '.join(external_imports())
    return __dockerfile_template__.format(version=version, modules=modules)

print(generate_dockerfile_from_current_environment())