pyenv setup under Ubuntu 21.04

Dockerfile

FROM ubuntu:21.04

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update \
    && apt-get install -y \
        # Tools for the pyenv installer script
        curl \
	git \
	# Tools to build python from source
	build-essential \
	libncursesw5-dev \
	libreadline-dev \
	libssl-dev \
	libsqlite3-dev \
	tk-dev \
	libgdbm-dev \
	libc6-dev \
	libbz2-dev \
	libffi-dev \
	zlib1g-dev

# Install pyenv
RUN curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash

# Configure the shell to be pyenv and pyenv-virtualenv aware
RUN echo 'export PATH=$PATH:~/.pyenv/bin' | tee -a ~/.bashrc \
    && echo 'eval "$(pyenv init --path)"' | tee -a ~/.bashrc \
    && echo 'eval "$(pyenv init -)"' | tee -a ~/.bashrc \
    && echo 'eval "$(pyenv virtualenv-init -)"' | tee -a ~/.bashrc

# Now it's possible to install python versions through pyenv and create virtualenvs
# docker build -t pyenv:local .
# docker run --rm -it pyenv:local bash
# > pyenv install 3.6.15
# > pyenv virtualenv 3.6.15 demo
# > python --version
# Python 3.6.15
# 🎉