Drupal 8 - End of Life

Drupal 8 officially went end-of-life in November 2021 (https://www.drupal.org/psa-2021-11-30). The focus of this issue is to gauge sentiment about (and identify tasks for) ending CiviCRM's Drupal 8.x support.

(Note: This issue has no impact on CiviCRM's support for Drupal 7 or Drupal 9 -- both continue to be supported by drupal.org and civicrm.org.)

Rationale

@DaveD made the case on Github as follows

• There's the 3 reasons already mentioned:
  • Has been EOL for 6 months
  • No security updates.
    • And there have been recent drupal security fixes which would have helped prompt people to move off 8 if they were still on it.
  • Civi works equally as well on 9 as on 8
• There's support for dropping it in chat, with nobody dissenting: https://chat.civicrm.org/civicrm/pl/qh6t761dt7gsdyp78m6stbmpwo
• Drupal 8 to 9 is very different than 6 to 7. Drupal 9 is identical to drupal 8.9 except for some deprecated functions. It's not much different than if they had called it 8.10.
  • There were many blog posts about this on the internet, about how easy it would be to upgrade compared to other jumps.
• There was plenty of awareness ahead of time in the drupal world that drupal 8 would be unsupported.
  • From May 2021 to November 2021, the only updates for drupal 8.9.x were security updates, with repeated notices that 8 was becoming EOL.
  • There was a module available that was pretty good about pointing out what if anything you needed to change.
• There is no CIVICRM_UF=Drupal9, because it's not needed.

I would add two more items in favor of dropping D8:

• Drupal 10 Support: Preserving D8 may make it harder to add D10. While most changes can be bridged to support 2 versions major (eg D8+D9 or D9+D10), it gets more complicated with 3 major versions (D8+D9+D10). We've encountered at least one issue (involving changes in Symfony Dispatcher / PSR-14) that gets prickly with 3 major versions.
• Pingbacks: There are only ~30 Civi deployments still reporting Drupal 8.x. They represent <1% of Civi-Drupal deployments.
  • Note: This is based on directly examining pingbacks from 2022 -- and only counting sites with multiple pingbacks (e.g. to exclude most ephemeral test-sites). The data on stats.civicrm.org is confusing in this regard, because Drupal 8.x and Drupal 9.x are lumped together with UF Drupal8. My comments are based on examining actual version-numbers and not just UF name.

Tasks

There are a few tasks to do as follow-up:

• Update installation guide
• Remove Drupal 8.x from test infra

Suggested Emojis

Please do register a quick reaction on D8 EOL. Some suggested emojis:

• 🚀 - Remove Drupal 8 compatibility at the soonest convenience.
• 🐢 - Remove Drupal 8 compatibility... just not quite yet. (Keep it until 5.51 ESR).
• 🛡 - Protect Drupal 8 compatibility for a longer period of time.
• ‼ - Extra importance modifier. (Add this if the sentiment on the first emoji is strong - eg if you will be significantly impacted by the issue.)

(Flag whichever is the soonest that you think is appropriate/acceptable.)

(Example: If you maintain a site that's been held back on D8 because of some complicated issue and cannot resolve it in the near future, then you could say "🛡 ‼".)

(You may see totten on all emojis for a while, since I put them in as placeholders.)