Portable python binaries

Portable-Python is a CLI (and a python library) for compiling python binaries from source than can be decompressed in any folder, and used from there without further ado (ie: no need to run an "installer").

Motivation

The idea here is to allow for automated systems to:

• Easily obtain a python binary, that can be used in sandboxes / workstations / laptops / instances...
• Inspect any python installation, and point out how portable it is, which shared or non-standard libraries it is using

Installation

portable-python is a regular python CLI, it can be installed with:

pickley:

pickley install portable-python
portable-python --help
portable-python inspect /usr/bin/python3

Or pipx:

pipx install portable-python
portable-python inspect /usr/bin/python3

Using pip install (a CI builder would probably do this):

/usr/bin/python3 -mvenv /tmp/pp
/tmp/pp/bin/python -mpip install portable-python
/tmp/pp/bin/portable-python --help
/tmp/pp/bin/portable-python inspect /usr/bin/python3

Supported operating systems

Portable python binaries can be built for Linux and MacOS (Intel/M1/M2).

Currently Windows is NOT supported, contributions are welcome.

Python binaries can be produced as "portable" (statically linked, can run from any folder where the binary is unpacked in), or with a --prefix (build targeted to live in a pre-determined folder, like /apps/pythonM.m)

Operating system	Portable	--prefix
Linux	✅	✅
Macos	✅	✅
Windows	❌	❌

Building a portable cpython

Once portable-python is installed:

Build a binary:

cd some-temp-folder
portable-python build 3.9.7
ls -l dist/cpython-3.9.7-macos-arm64.tar.gz

Unpack it somewhere:

tar -C ~/tmp/versions/ -xf dist/cpython-3.9.7-macos-arm64.tar.gz
ls -l ~/tmp/versions/

It's ready to be used:

~/tmp/versions/3.9.7/bin/python --version

Note that you can use --dryrun mode to inspect what would be done without doing it:

$ portable-python --dryrun build 3.9.7

INFO selected: xz openssl gdbm (3 modules) xz:5.2.5 openssl:1.1.1k gdbm:1.18.1
INFO Platform: macos-x86_64
...
--------------
-- xz:5.2.5 --
--------------
Would download https://tukaani.org/xz/xz-5.2.5.tar.gz
Would untar build/sources/xz-5.2.5.tar.gz -> build/components/xz
INFO env PATH=build/deps/bin:/usr/bin:/bin
INFO env MACOSX_DEPLOYMENT_TARGET=10.14
Would run: ./configure --prefix=build/deps --enable-shared=no --enable-static=yes ...
...
-------------------
-- cpython:3.9.7 --
-------------------
Would download https://www.python.org/ftp/python/3.9.7/Python-3.9.7.tar.xz
Would untar build/sources/Python-3.9.7.tar.xz -> build/components/cpython
...
Would run: ./configure --prefix=/ppp-marker/3.9.7 --enable-optimizations ...
Would run: /usr/bin/make
Would run: /usr/bin/make install DESTDIR=build
...
Would tar build/3.9.7 -> dist/cpython-3.9.7-macos-x86_64.tar.gz

Library

Portable Python can be used as a python library to invoke builds, or inspect an installation.

Invoke a build from python code:

from portable_python import BuildSetup

setup = BuildSetup("cpython:3.9.7")
setup.compile()

Invoke an inspection from python code:

from portable_python.inspector import PythonInspector

inspector = PythonInspector("/usr/bin/python3")
print(inspector.represented())
problem = inspector.full_so_report.get_problem(portable=True)
if problem:
    print("oops, it is not portable!: %s" % problem)

From source, contributions welcome!:

git clone https://github.com/codrsquad/portable-python.git
cd portable-python
python3 -mvenv .venv
.venv/bin/pip install -r requirements.txt -r tests/requirements.txt
.venv/bin/pip install -e .
.venv/bin/portable-python --help
.venv/bin/portable-python inspect /usr/bin/python3

tox -e py311
tox -e style

Build folder structure

portable-python uses this file structure (build/ and dist/ folders configurable):

build/
    ppp-marker/3.9.7/                   # Full installation (after build completes)
    components/                         # Builds of statically compiled extension modules are here
    deps/                               # --prefix=.../deps passed to all component ./configure scripts
    sources/
        openssl-1.1.1k.tar.gz           # Downloaded artifacts (downloaded only once)
dist/
    cpython-3.9.7-macos-arm64.tar.gz    # Ready-to-go portable binary tarball

Guiding principles

• Focuses on just one thing: compile a portable python, and validate that it is indeed portable, produce outcome in (configurable) ./dist/ folder and that's it
• No patches: C compilation is done as simply as possible without modifying the upstream source code. Rely solely on the make/configure scripts, typically via stuff like --enable-shared=no
• Builds are validated, an important part of the effort was to write up code that is able to inspect a python installation and detect whether it is portable or not (and why not if so).
• Only the last few non-EOL versions of python are supported (no historical stuff)
• As time goes on, the code of this tool will evolve so that the latest pythons keep building (but won't worry that older versions still keep building)

For this repo itself:

• Code is pure python, it is a CLI with one entry-point called portable-python
  • Can be ran in a debugger
  • 100% test coverage, has a --dryrun mode to help with testing / debugging / seeing what would be done quickly
  • No shell scripts (those are hard to maintain/test/debug)
  • Can be pip install-ed and reused