OMERO.web upgrade to Django 3.2

Introduction

Since 5.6.0, OMERO.web has depended on Django 1.11.x. This version left extended support in April 2020 ¹. Django version conservatism has helped us establish a very fertile, stable environment for plugin developers. Furthermore, the usage of the plethora of Django functionality available in core OMERO.web is quite limited.

Running a version of any software that the authors consider unsupported is risky; if any bugs of either class are found they will not be fixed upstream. However, we are not currently aware of any security or data loss bugs in the latest available versions of Django 1.11.x that affect OMERO.web.

For the future safety of the community as well as enhanced developer ergonomics we need to upgrade Django. This was first attempted, targetting Django 2.2, during the summer of 2020 ². Unfortunately, that work never came to fruition and Django 2.2.x leaves Long Term Support in just a few months (April 2022). Consequently, we have reactivated the work ³ and plan to upgrade to Django 3.2.x this Spring.

Path to release

By the end of March 2022 we plan to have a release candidate version of OMERO.web with Django 3.2.x as a dependency to be made available for the community to evaluate. We will notify the community as soon as this release candidate is available. In anticipation of this we are recommending that all plugin developers pin their omero-web dependencies to <5.14.0 and make a release of their plugin as soon as possible.

Plugin developers are encouraged to review the release notes, in particular the Backwards incompatible and Features deprecated for all major Django versions since 1.11.x to ensure they can be compliant with the new APIs. They are as follows:

• Django 2.0 release notes
• Django 2.1 release notes
• Django 2.2 release notes
• Django 3.0 release notes
• Django 3.1 release notes
• Django 3.2 release notes

The OME team will be publishing a migration guide along with the release candidate to draw the attention of plugin developers to specific OMERO.web idioms and design patterns that will change in this new major version. Those developers wishing to observe this process in real time may do so by watching the progress on the upgrade PR ³ or the overhauling GitHub project ⁴.

Every attempt has been made to make the absolute minimum number of changes required to maintain OMERO.web functionality and leave potential Django infrastructure modernisation to other follow up PRs.

NOTE: The supported Python versions for Django 3.2.x are currently 3.6, 3.7, 3.8, 3.9, and 3.10 ⁵. At this time for changes to include Python 3.10 support are not planned.