Prepare Yarn v1 removal in Node.js 26 images

[MikeMcC399]

• Proposes to implement Remove unsupported Yarn v1.22 from docker-node base images #2264 for Node.js >=26
• Follows on from PR Deprecate Yarn v1 #2368

Problem

• Images include Yarn v1 by default

• TSC endorsed the removal of Yarn v1 for images based on Node.js 26 and above as currently described in Yarn v1 Classic bundling

Suggested Solution

• Update each of the template files to add beginning and end markers for the Yarn installation section

  • Dockerfile-alpine.template

  • Dockerfile-debian.template

  • Dockerfile-slim.template

    # YARN_INSTALLATION_START
    ENV YARN_VERSION=0.0.0
    
    RUN set -ex \
    # use pre-existing gpg directory, see https://github.com/nodejs/docker-node/pull/1895#issuecomment-1550389150
    && export GNUPGHOME="$(mktemp -d)" \
        ...
    # smoke test
    && yarn --version \
    && rm -rf /tmp/*
    # YARN_INSTALLATION_END

• In update.sh use sed to remove the marked Yarn installation section for version >= 26 when specific Dockerfiles are created based on the templates

• Update documentation accordingly

• This should be implemented before the planned release date of Node.js 26.0.0 on 2026-04-22

[MikeMcC399]

There will be at least one more PR to prepare for Node.js 26, which would involve updating the versions.json to add 26.

I would suggest creating a new feature branch, for example node-26 to collect and test updates from PRs before they're merged into main. Perhaps one of the regular maintainers could consider that suggestion and create that branch if it sounds like it would be useful?

[MikeMcC399]

I found multiple issues in the update.sh script when I was looking at possible ways to implement the removal of Yarn:

• update -s script corrupts Yarn version #2411
• update -h script help option non-working examples #2412
• update script misleading log when nothing updated #2413

It would be cleaner, if these could be addressed first.

[sxa]

FYI @nodejs/docker

Initial proposed wording for a social media post on this change based on something I posted on Mastodon - comments welcome before it gets submitted to the social team either here ot in the #nodejs-distributions slack channel:

Starting with the next major release of Node.js (version 26 which is due near the end of April) the "official" container images hosted on dockerhub will no longer include the Yarn V1 package manager which is no longer maintained.

Since this is a potentially breaking change for some use cases this change will not apply to earlier releases although it will affect anyone who is not pinning to a specific node major version when #NodeJS 26 comes out.

Ref: https://github.com/nodejs/docker-node/

(This could be updated to include a reference to the node.js snaps since they may also be removed in v26)

[MikeMcC399]

Starting with the next major release of Node.js (version 26 which is due near the end of April) the "official" container images hosted on dockerhub will no longer include the Yarn V1 package manager which is no longer maintained.

That should probably be either the full url https://hub.docker.com/_/node or the name "Docker Hub", although admittedly dockerhub.com does forward to https://hub.docker.com

(This could be updated to include a reference to the node.js snaps since they may also be removed in v26)

Pleasingly there has been some reaction and movement in the https://github.com/nodejs/snap repo, and I read that they're planning to remove Yarn in Node.js 25 already. (Node.js 25 is currently missing over there.) But that's really off-topic for here. Just wanted to mention it, since you brought it up!

[nschonni]

Thinking out loud, and I'll try and PR something later to update the update.sh:

if  [ "${nodeVersion:0:2}" -ge "26" ]; then
  sed '/ENV YARN_VERSION/,/rm -rf \/tmp\/\*/ d'
fi

Other possible options:

1. I was thinking about pulling it out or the templates and conditionally adding
2. Use the same conditional version check in the RUN statement in the templates. I had played with that a little before, but I think some of my line continuations were tripping up the docker build runs.

[MikeMcC399]

@nschonni
I'm happy to leave these changes to you. The necessary logic has become simpler since you put the Yarn version inline.

My original idea is in https://github.com/MikeMcC399/docker-node/tree/no-yarn-node-26, rebased on your latest changes. I haven't re-tested it though.