Base Image Change (Bookworm → Trixie)

[Llewellynvdm]

There's an upstream change in the PHP official images that affects us. See the PR here for context:
🔗 docker-library/official-images#19660

What happened?

• Until now, our Joomla images using FROM php:x.y-foo (for example php:8.3-apache) were built on Debian Bookworm.
• With the PHP update above, the unqualified tags (php:x.y-foo without a -bookworm or -trixie suffix) now default to Debian Trixie.
• That means if we rebuild today without changes, our base OS silently shifts from Bookworm (Debian 12) to Trixie (Debian 13).

Why did they do this?

The PHP maintainers (and Docker Library maintainers in general) want unqualified tags to always point to the current Debian stable release. This reduces confusion and duplicate tags. If you want to stay on a fixed base, you now need to pin it explicitly (e.g. php:8.3-apache-bookworm).

What are our options?

1. Pin to Bookworm: Explicitly use php:8.3-apache-bookworm (and the FPM variants, etc.) so builds stay on Debian 12 until we decide to move. This avoids surprises but means we'll eventually have to make a conscious jump to Trixie later.
2. Move to Trixie now: Accept the new default and let Joomla Docker images follow Debian's stable track. This reduces maintenance overhead and keeps us aligned with upstream, but comes with the usual Debian major-version churn (newer libc, OpenSSL, ICU, etc.), which may have knock-on effects for extensions or package installs.

What do we need to decide?

• Should we stick with Bookworm for now (and explicitly pin), or
• Should we move forward to Trixie right away and update docs accordingly?

Personally, I can see the benefit of just moving on to Trixie to stay aligned, but I also understand the value of giving everyone time to prepare by staying on Bookworm a bit longer.

I'd love to hear the community's thoughts on this—especially from those running Joomla in production via these Docker images. Do you prefer stability (pin to Bookworm) or staying current (move to Trixie)?

[Llewellynvdm]

We've decided to move forward with Debian Trixie as the base for Joomla 5 and above. This means our Joomla 5+ Docker images will follow the upstream PHP defaults and build on Trixie going forward. For Joomla 4.4, we're removing those builds for now to avoid late lifecycle disruption, but if a 4.4 security release comes along, we'll reintroduce it explicitly pinned to Bookworm to ensure stability.

So in short: Joomla 5+ moves with upstream to Trixie, Joomla 4.4 is paused unless security requires otherwise (in which case it'll be Bookworm-pinned). If anyone runs into Trixie-specific quirks—whether that's package availability, extension compatibility, or runtime differences—please share them here so we can track and adjust if needed.