Please read the question carefully before closing as duplicate, I believe the use case to be unique.
I'm trying to create a docker image that only has python 3.7 installed, the problem is that if I try to install pip, the command also installs python 3.6 which I do not want.
The relevant part of the ideal docker file I'm tinkering is as follows
FROM ubuntu:18.04
# Upgrade installed packages
RUN apt-get update && apt-get upgrade -y && apt-get clean
# (...)
# Python package management and basic dependencies
RUN apt-get install -y python3.7 python3.7-dev python3.7-pip
# Register the version in alternatives
RUN update-alternatives --install /usr/bin/python python /usr/bin/python3.7 1
# Set python 3 as the default python
RUN update-alternatives --set python /usr/bin/python3.7
# Upgrade pip to latest version
RUN python -m ensurepip --upgrade
# (...)
This would fail as python3.7-pip doesn't seem to exist; only python3-pip does, which is what installs python 3.6 for some reason.
I tried not installing pip at all and doing it manually, like so
# (...)
RUN apt-get install -y python3.7 python3.7-dev
# (...)
RUN curl 'https://bootstrap.pypa.io/get-pip.py' > get-pip.py
RUN python get-pip.py pip --no-setuptools --no-wheel
Which fails with this error:
Traceback (most recent call last):
File "get-pip.py", line 21492, in <module>
main()
File "get-pip.py", line 197, in main
bootstrap(tmpdir=tmpdir)
File "get-pip.py", line 82, in bootstrap
import pip._internal
File "/tmp/tmpbez2vju9/pip.zip/pip/_internal/__init__.py", line 40, in <module>
File "/tmp/tmpbez2vju9/pip.zip/pip/_internal/cli/autocompletion.py", line 8, in <module>
File "/tmp/tmpbez2vju9/pip.zip/pip/_internal/cli/main_parser.py", line 8, in <module>
File "/tmp/tmpbez2vju9/pip.zip/pip/_internal/cli/cmdoptions.py", line 14, in <module>
ModuleNotFoundError: No module named 'distutils.util'
Again, installing python3-distutils results in python 3.6 appearing in the system
So, is there a way to install ONLY a fully functional python 3.7 in ubuntu 18.04, WITHOUT having to install python 3.6?
In case someone else is ok with getting Python3.6 installed as a side effect (python3.7-distutils introduces it as pointed out by OP). This will install Python3.7 making it default and have the latest available pip using your python3.7 installation
FROM ubuntu:18.04
# Upgrade installed packages
RUN apt-get update && apt-get upgrade -y && apt-get clean
# (...)
# Python package management and basic dependencies
RUN apt-get install -y curl python3.7 python3.7-dev python3.7-distutils
# Register the version in alternatives
RUN update-alternatives --install /usr/bin/python python /usr/bin/python3.7 1
# Set python 3 as the default python
RUN update-alternatives --set python /usr/bin/python3.7
# Upgrade pip to latest version
RUN curl -s https://bootstrap.pypa.io/get-pip.py -o get-pip.py && \
python get-pip.py --force-reinstall && \
rm get-pip.py
# (...)
I see two choices:
or
The solution by @donhector has two subtle problems:
ppa:deadsnakes to get newer versionspython it breaks the convention that python is used for Python 2.x. This might break apt, see How to update-alternatives to Python 3 without breaking apt?A solution without these problems is:
FROM ubuntu:18.04
# Upgrade installed packages
RUN apt update && apt upgrade -y && apt clean
# install python 3.7.10 (or newer)
RUN apt update && \
apt install --no-install-recommends -y build-essential software-properties-common && \
add-apt-repository -y ppa:deadsnakes/ppa && \
apt install --no-install-recommends -y python3.7 python3.7-dev python3.7-distutils && \
apt clean && rm -rf /var/lib/apt/lists/*
# Register the version in alternatives (and set higher priority to 3.7)
RUN update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 1
RUN update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.7 2
# Upgrade pip to latest version
RUN curl -s https://bootstrap.pypa.io/get-pip.py -o get-pip.py && \
python3 get-pip.py --force-reinstall && \
rm get-pip.py