Hi folks, [Note: this may not make much sense to folks that haven't been closely following the Modular Server work for F27. If that's you, sorry - hopefully this will be more comprehensible by the time I officially propose it for F28, as the relevant terminology becomes more widely understood. In the meantime, check out https://docs.pagure.org/modularity/ to learn more]
I'm working on a draft proposal for a "Default Python" module (see https://fedora-python.readthedocs.io/en/latest/plans/default-python-module/ for details), and hit an interesting challenge when it comes to defining the containing images that we want to be able to build from our module definitions. A quick summary of what I'm expecting we'll have by F28: - a separate platform-python binary in the Platform module - python2 modules with a full 2.7 stream and a partial interpreter-only 2.6 stream - python3 modules with a full 3.6 stream and a TBD set of other streams - a default-python module to switch between no-default, python2-default and python3-default With those modules defined, a minimal Fedora container image will only include platform-python, but we'd at least also have Python3-F28, and Python2-F28 images that included the respective user Python stack in addition to the platform Python runtime. The part I'm struggling with is this: Python 3.7.0 is expected to be released in June 2018, while Fedora 28 is due out in May 2018. It would be *really nice* to be able to define a Fedora 28 based Python 3.7 container where "/usr/bin/python" and "/usr/bin/python3" were both references to "/usr/bin/python3.7". The challenge with actually doing that lies in the "/usr/bin/python3" symlink: integrated userspace Python applications in F28 are going to expect that to still refer to the Python 3.6 stream. One way I could potentially see this working: * the normal non-conflicting setup is as follows: * the python3 3.6 stream includes a "/usr/bin/python3" symlink * the other python3 3.x streams do *not* include such a symlink & hence don't conflict * the default-python python3-default stream does *not* include such a symlink & hence doesn't conflict We then add some more streams to the default-python module that *do* include a "/usr/bin/python3" symlink: python3.5-default, python3.7-default, etc The trick with these streams is that they would *conflict* with the regular python3 3.6 stream, due to the disagreement over what "/usr/bin/python" means. That dependency resolution conflict would then mean that have a non-default version of Python 3.x configured as the default when defining your container would *prevent* you from including any regular userspace Python components - you'd only be able to include the ones built specifically for that stream. Does that approach sound sufficiently plausible to folks that I can use it to provide feedback to the folks working on the modularity tooling as to the capabilities we think we'll need? Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ python-devel mailing list -- python-devel@lists.fedoraproject.org To unsubscribe send an email to python-devel-le...@lists.fedoraproject.org
