django.core.cache.backends.memcached.MemcachedCache backend is removed

[Corey Bryant]

[Description]
In 4.1 the django.core.cache.backends.memcached.MemcachedCache backend is removed.

https://github.com/django/django/blob/main/docs/releases/4.1.txt#L749

It's been deprecated since 3.2:

https://docs.djangoproject.com/en/4.2/releases/3.2/#features-deprecated-in-3-2

"The django.core.cache.backends.memcached.MemcachedCache backend is deprecated as python-memcached has some problems and seems to be unmaintained. Use django.core.cache.backends.memcached.PyMemcacheCache or django.core.cache.backends.memcached.PyLibMCCache instead."

This results in the following error on Ubuntu Mantic:

InvalidCacheBackendError at /
Could not find backend 'django.core.cache.backends.memcached.MemcachedCache': Module "django.core.cache.backends.memcached" does not define a "MemcachedCache" attribute/class
Request Method: GET
Request URL: http://10.5.3.66/horizon/
Django Version: 4.2.4
Exception Type: InvalidCacheBackendError
Exception Value:
Could not find backend 'django.core.cache.backends.memcached.MemcachedCache': Module "django.core.cache.backends.memcached" does not define a "MemcachedCache" attribute/class
Exception Location: /usr/lib/python3/dist-packages/django/core/cache/__init__.py, line 49, in create_connection
Python Executable: /usr/bin/python3
Python Version: 3.11.6
Python Path:
['/usr/lib/python3/dist-packages',
 '/usr/lib/python311.zip',
 '/usr/lib/python3.11',
 '/usr/lib/python3.11/lib-dynload',
 '/usr/local/lib/python3.11/dist-packages',
 '/usr/lib/python3/dist-packages',
 '/usr/lib/python3/dist-packages/openstack_dashboard']
Server time: Thu, 12 Oct 2023 20:44:30 +0000

[Test Case]
Deploy openstack with the openstack-dashboard (horizon) on Ubuntu mantic. Ensure the dashboard is functional and no errors in /var/log/apache/error.log.

[Regression Potential]
This fix is inline with the upstream. Currently the dashboard is not functional without this fix.

[Corey Bryant (corey.bryant)]

If the horizon package fix is needed before the SRU lands, it is available in https://launchpad.net/~corey.bryant/+archive/ubuntu/mantic-bobcat

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/charm-openstack-dashboard/+/898246

[Takashi Kajinami (kajinamit)]

There is a patch to update the default cache backend. We can probably use it.
 https://review.opendev.org/c/openstack/horizon/+/891828

[Corey Bryant (corey.bryant)]

Ubuntu package update uploaded to noble and mantic unapproved queue.

[Launchpad Janitor (janitor)]

This bug was fixed in the package horizon - 4:23.3.0-0ubuntu2

---------------
horizon (4:23.3.0-0ubuntu2) noble; urgency=medium

  * d/p/ubuntu_settings.patch, d/p/switch-to-pymemcachecache-backend.patch,
    d/control: Switch to python3-pymemcache and PyMemcacheCache driver as
    the Django MemcachedCache backend was removed in Django 4.1 in favor of
    the PyMemcacheCache or PyLibMCCache backend (LP: #2039225).
  * d/p/ubuntu_settings.patch: Rebase and apply on top of
    switch-to-pymemcachecache-backend.patch.
  * d/gbp.conf, .launchpad.yaml: Sync from cloud-archive-tools for
    caracal.

 -- Corey Bryant <email address hidden> Thu, 12 Oct 2023 17:17:26 -0400

[Steve Langasek (vorlon)]

Hello Corey, or anyone else affected,

Accepted horizon into mantic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/horizon/4:23.3.0-0ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-mantic to verification-done-mantic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-mantic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Corey Bryant (corey.bryant)]

Hello Corey, or anyone else affected,

Accepted horizon into bobcat-proposed. The package will build now and be available in the Ubuntu Cloud Archive in a few hours, and then in the -proposed repository.

Please help us by testing this new package. To enable the -proposed repository:

  sudo add-apt-repository cloud-archive:bobcat-proposed
  sudo apt-get update

Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-bobcat-needed to verification-bobcat-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-bobcat-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Corey Bryant (corey.bryant)]

openstack-dashboard is functional on mantic-proposed
version tested: 4:23.3.0-0ubuntu1.1

[Corey Bryant (corey.bryant)]

openstack-dashboard is functional on bobcat-proposed
version tested: openstack-dashboard/jammy-proposed,now 4:23.3.0-0ubuntu1.1~cloud0 all [installed]

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/horizon/+/891828
Committed: https://opendev.org/openstack/horizon/commit/caa99b2010bd914bbe3cb2779940b7c544fe1104
Submitter: "Zuul (22348)"
Branch: master

commit caa99b2010bd914bbe3cb2779940b7c544fe1104
Author: Radomir Dopieralski <email address hidden>
Date: Thu Aug 17 17:06:14 2023 +0200

    Switch to PyMemcacheCache backend

    The new library is already supported in django 3.2 and gives us better
    support for IPv6 addresses and encrypted connections.

    Also, the same library is being used by all other OpenStack projects.

    Depends-on: https://review.opendev.org/c/openstack/devstack/+/898302
    Closes-Bug: #2039225
    Change-Id: I964ac4d0d62dff4c1f7c1f1373763fbf23024269

[Timo Aaltonen (tjaalton)]

The verification of the Stable Release Update for horizon has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package horizon - 4:23.3.0-0ubuntu1.1

---------------
horizon (4:23.3.0-0ubuntu1.1) mantic; urgency=medium

  * d/p/ubuntu_settings.patch, d/p/switch-to-pymemcachecache-backend.patch,
    d/control: Switch to python3-pymemcache and PyMemcacheCache driver as
    the Django MemcachedCache backend was removed in Django 4.1 in favor of
    the PyMemcacheCache or PyLibMCCache backend (LP: #2039225).
  * d/p/ubuntu_settings.patch: Rebase and apply on top of
    switch-to-pymemcachecache-backend.patch.
  * d/gbp.conf: Create stable/2023.2 branch.
  * d/gbp.conf, .launchpad.yaml: Sync from cloud-archive-tools for
    bobcat.

 -- Corey Bryant <email address hidden> Thu, 26 Oct 2023 14:38:06 -0400

[Corey Bryant (corey.bryant)]

This bug was fixed in the package horizon - 4:23.3.0-0ubuntu1.1~cloud0
---------------

 horizon (4:23.3.0-0ubuntu1.1~cloud0) jammy-bobcat; urgency=medium
 .
   * New update for the Ubuntu Cloud Archive.
 .
 horizon (4:23.3.0-0ubuntu1.1) mantic; urgency=medium
 .
   * d/p/ubuntu_settings.patch, d/p/switch-to-pymemcachecache-backend.patch,
     d/control: Switch to python3-pymemcache and PyMemcacheCache driver as
     the Django MemcachedCache backend was removed in Django 4.1 in favor of
     the PyMemcacheCache or PyLibMCCache backend (LP: #2039225).
   * d/p/ubuntu_settings.patch: Rebase and apply on top of
     switch-to-pymemcachecache-backend.patch.
   * d/gbp.conf: Create stable/2023.2 branch.
   * d/gbp.conf, .launchpad.yaml: Sync from cloud-archive-tools for
     bobcat.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-openstack-dashboard/+/898246
Committed: https://opendev.org/openstack/charm-openstack-dashboard/commit/16c5a026419e5c23ab4e7777cec8deb15c25ee6f
Submitter: "Zuul (22348)"
Branch: master

commit 16c5a026419e5c23ab4e7777cec8deb15c25ee6f
Author: Corey Bryant <email address hidden>
Date: Fri Oct 13 14:57:46 2023 -0400

    Add local_settings.py template for Bobcat

    This fixes issues found in testing with Django 4 in mantic.

    ugettext_lazy was deprecated in Django 3.0 and removed in
    Django 4.0. Switch to gettext_lazy.

    Switch to PyMemcacheCache backend as the Django MemcachedCache
    backend was removed in Django 4.1 in favor of the PyMemcacheCache
    or PyLibMCCache backend. This depends on a new openstack-dashboard
    package version that will be provided in an SRU for bug #2039225.

    Closes-Bug: #2039226
    Closes-Bug: #2039225
    Change-Id: Ia8e4f6f5f50d58268e4c6fa80c9f9c65a56a26ea

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/2023.2
Review: https://review.opendev.org/c/openstack/charm-openstack-dashboard/+/901561

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-openstack-dashboard/+/901561
Committed: https://opendev.org/openstack/charm-openstack-dashboard/commit/dec3e0158f0fc7c484e3fc2ffd8fa31c166f9b58
Submitter: "Zuul (22348)"
Branch: stable/2023.2

commit dec3e0158f0fc7c484e3fc2ffd8fa31c166f9b58
Author: Corey Bryant <email address hidden>
Date: Fri Oct 13 14:57:46 2023 -0400

    Add local_settings.py template for Bobcat

    This fixes issues found in testing with Django 4 in mantic.

    ugettext_lazy was deprecated in Django 3.0 and removed in
    Django 4.0. Switch to gettext_lazy.

    Switch to PyMemcacheCache backend as the Django MemcachedCache
    backend was removed in Django 4.1 in favor of the PyMemcacheCache
    or PyLibMCCache backend. This depends on a new openstack-dashboard
    package version that will be provided in an SRU for bug #2039225.

    Closes-Bug: #2039226
    Closes-Bug: #2039225
    Change-Id: Ia8e4f6f5f50d58268e4c6fa80c9f9c65a56a26ea
    (cherry picked from commit 16c5a026419e5c23ab4e7777cec8deb15c25ee6f)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 23.4.0 release.