From Fedora Project Wiki
(Summary update, add myself to owners)
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== Summary ==
 
== Summary ==
 
<!-- A sentence or two summarizing what this change is and what it will do. This information is used for the overall changeset summary page for each release. -->
 
<!-- A sentence or two summarizing what this change is and what it will do. This information is used for the overall changeset summary page for each release. -->
This change is about upgrading {{package|python-django}} to version 2.0. The latest Django release [https://docs.djangoproject.com/en/2.0/releases/2.0/#python-compatibility drops support for Python 2], but a few Django apps packaged in Fedora do not yet support Python 3.  
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This change is about upgrading {{package|python-django}} to version 2.0. The latest Django release [https://docs.djangoproject.com/en/2.0/releases/2.0/#python-compatibility drops support for Python 2], but a few Django apps packaged in Fedora do not yet support Python 3. A compatibility package will be provided for those.
  
 
== Owner ==
 
== Owner ==
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<!-- Expand on the summary, if appropriate.  A couple sentences suffices to explain the goal, but the more details you can provide the better. -->
 
<!-- Expand on the summary, if appropriate.  A couple sentences suffices to explain the goal, but the more details you can provide the better. -->
The latest Django release 2.0 finally drops support for Python 2.7. Not all dependent applications can keep up with Djangos pace. This change describes a way how to enable both, keeping 2.7 compatibility and also leveraging the latest version.
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The latest Django release 2.0 finally drops support for Python 2.7. Not all dependent applications in Fedora can keep up with Djangos pace. This change describes a way how to enable both, keeping 2.7 compatibility and also leveraging the latest version.
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The {{package|python-django}} package will be updated to 2.0, Python 2 subpackage(s) will be removed. A new compatibility {{package|python2-django1.11}} package will be created with Python 2 version of Django 1.11. The Django 1.11.x series is the last to support Python 2.7, it also has Long Term Support (supported until April 2020 by upstream). See the [https://docs.djangoproject.com/en/2.0/releases/2.0/#python-compatibility Django 2.0 release notes] for details about Django compatibility with various Python versions.
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Note that whether this will be a Python 2 only package or rather {{package|python-django1.11}} SRPM creating both {{package|python2-django1.11}}  and {{package|python3-django1.11}} packages is yet to be decided.
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The new {{package|python2-django1.11}} package will obsolete <code>python2-django < 2</code> and <code>python-django < 2</code>, but it will deliberately not provide either of those. This would make packages depending on <code>python(2)-django</code> FTBFS. This is intentional. If we don't do that, all Django packages in Fedora will just keep dragging the Legacy Python dependency chain forever. Package owners of Django applications requiring Python 2 will need to manually adjust their dependencies to use <code>python2-django</code> or move to Python 3 only (this is preferred but not always possible). Package owners of Django libraries will need to coordinate this with package owners of the applications. The rule of thumb is: If the library is not required by an application (packaged in Fedora) that uses Legacy Python, remove the Python 2 subpackage (or retire the package, if it does cannot support Python 3).
  
 
== Benefit to Fedora ==
 
== Benefit to Fedora ==
Fedora will be able to provide both: latest and current release and also a fallback for applications, which do not support Python3 yet.
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Fedora will be able to provide both: latest and current release of Django and also a fallback for applications, which do not support Python 3 yet.
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This will also remove some Legacy packages nobody is actively taking care of.
 
   
 
   
 
    
 
    

Revision as of 13:39, 12 December 2017


Django 2.0

Summary

This change is about upgrading Package-x-generic-16.pngpython-django to version 2.0. The latest Django release drops support for Python 2, but a few Django apps packaged in Fedora do not yet support Python 3. A compatibility package will be provided for those.

Owner

Current status

  • Targeted release: Fedora 28
  • Last updated: 2017-12-12
  • Tracker bug: <will be assigned by the Wrangler>

Detailed Description

The latest Django release 2.0 finally drops support for Python 2.7. Not all dependent applications in Fedora can keep up with Djangos pace. This change describes a way how to enable both, keeping 2.7 compatibility and also leveraging the latest version.

The Package-x-generic-16.pngpython-django package will be updated to 2.0, Python 2 subpackage(s) will be removed. A new compatibility Package-x-generic-16.pngpython2-django1.11 package will be created with Python 2 version of Django 1.11. The Django 1.11.x series is the last to support Python 2.7, it also has Long Term Support (supported until April 2020 by upstream). See the Django 2.0 release notes for details about Django compatibility with various Python versions.

Note that whether this will be a Python 2 only package or rather Package-x-generic-16.pngpython-django1.11 SRPM creating both Package-x-generic-16.pngpython2-django1.11 and Package-x-generic-16.pngpython3-django1.11 packages is yet to be decided.

The new Package-x-generic-16.pngpython2-django1.11 package will obsolete python2-django < 2 and python-django < 2, but it will deliberately not provide either of those. This would make packages depending on python(2)-django FTBFS. This is intentional. If we don't do that, all Django packages in Fedora will just keep dragging the Legacy Python dependency chain forever. Package owners of Django applications requiring Python 2 will need to manually adjust their dependencies to use python2-django or move to Python 3 only (this is preferred but not always possible). Package owners of Django libraries will need to coordinate this with package owners of the applications. The rule of thumb is: If the library is not required by an application (packaged in Fedora) that uses Legacy Python, remove the Python 2 subpackage (or retire the package, if it does cannot support Python 3).

Benefit to Fedora

Fedora will be able to provide both: latest and current release of Django and also a fallback for applications, which do not support Python 3 yet.

This will also remove some Legacy packages nobody is actively taking care of.


Scope

  • Proposal owners: drop Python2 subpackage from python-django, upgrade python-django to Django-2.0 and package Django-1.11.x for Python2 only.
  • Other developers: Other developers, whose applications do work with Python3 and Django 2.0 will need to change the requirement to python3-django.
  • Policies and guidelines:
    • Python packaging guidelines
    • Documentation should be provided
  • Trademark approval: N/A (not needed for this Change)

Upgrade/compatibility impact

N/A (not a System Wide Change)

How To Test

You should be able to install two web-apps, one requiring python2-django and one requiring python3-django. (TODO: provide actual package names)

  1. dnf install (package 1)
  2. see python2-django is installed as dependency
  3. run that package
  4. dnf install (package 2)
  5. verify python3-django is installed as dependency
  6. package 1 still works
  7. package 2 works as well
  8. dnf remove package 1
  9. package 2 still works

User Experience

N/A (not a System Wide Change)

Dependencies

N/A (not a System Wide Change)

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)
  • Contingency deadline: N/A (not a System Wide Change)
  • Blocks release? N/A (not a System Wide Change), Yes/No
  • Blocks product? product

Documentation

N/A (not a System Wide Change)

Release Notes