Update default_variant to trixie

[MikeMcC399]

Problem

The default image as defined in

docker-node/config

Line 2 in 4c215dc

default_variant bookworm

is bookworm.

confirmed also by

$ docker run --rm --entrypoint cat node:25.5 /etc/debian_version
12.13

https://www.debian.org/releases/ shows

Version	Code Name	Release Date	Status
13	Trixie	2025-08-09	stable
12	Bookworm	2023-06-10	oldstable

Solution

Update the default_variant to trixie.

Add the information to README > node: which currently does not state which operating system and version the default is based on.

Alternatives to Consider

Stay with bookworm

EOL is however 2026-06-10 (with later dates for End of LTS and End of ELTS).

[MikeMcC399]

If this makes sense and is welcome I'll submit a PR to implement.

[sxa]

I think it's ok having a distribution in active LTS be used so sticking with bookworm would be viable (Part of me wonders if explicitly sticking with one in the LTS phase is a good idea for stability!) but if we don't have a policy on these upgrades we should probably look at getting one defined.

But given where we are at the moment, I'm personally ok with switching the default - do we need to announce such changes anywhere first?

[MikeMcC399]

@sxa

if we don't have a policy on these upgrades we should probably look at getting one defined.

That does seem to be a generally missing document that describes what's included, or not, and how changes are decided on.

Regarding the update itself, perhaps just start with adding some text to the README?

• stating that bookworm is the current default OS
• describing the advantages / disadvantages of pinning or not pinning to a chosen OS
• with a warning that the underlying default OS / version may change
• and a mention of a future planning date for the transition from bookworm to trixie as default

Instead of making the change now with no advanced warning, first choose a planning date and publish it.

The EOL date for bookworm might be appropriate (2026-06-10, or the release of Node.js 26 (2026-04-22), for instance.

[sxa]

The EOL date for bookworm might be appropriate

I do wonder whether for Debian that June date isn't so much of a notable event since major architectures (arm and x64) should still receive public (without a subscription) support from a security perspective for much longer from the LTS team (so on that basis I wouldn't necessarily recommend that we stop publishing bookworm images in June)

So basically we should also consider the policy for stopping old images as well as when to switch to new ones - worst case we continue publishing them until the OS goes out of public Long Term Support - which is likely when Dockerhub's official images would stop supporting it too.

[MikeMcC399]

@sxa

This issue was only intended to be about setting the default image to trixie, not about stopping distributing bookworm based images when they are explicitly selected.

Nevertheless it would definitely be helpful to put down some guidelines for Alpine and Debian about introduction and retirement based on upstream lifecycle dates. I don't believe that is described anywhere in this repo.