Related tasks for Alpine (musl) x64 promotion to Tier 2

[MikeMcC399]

Current status

Platform list currently contains the following entry:

Operating System	Architectures	Versions	Support Type	Notes
GNU/Linux	x64	kernel >= 3.10, musl >= 1.1.19	Experimental	e.g. Alpine 3.8

Other architectures are unlisted, and have no designated support type.

Official binary platforms and toolchains does not list any Alpine / musl build.

node Docker images for Alpine are built from https://unofficial-builds.nodejs.org/download/release/v<node-version>/node-v<node-version>-linux-x64-musl.tar.xz

• Alpine x64 images are built using the x64-musl build directly
• Alpine arm64, arm32 and s390x images are built from source

Update automation treats security releases differently and proceeds with these releases without waiting for musl build availability.

Proposed Node.js change

PR nodejs/node#63737 proposes the promotion of Alpine/x64 to Tier 2.

This can be expected to add Alpine/x64 to the Platform list and to Official binary platforms and toolchains.

An x64-musl build can be expected to be available through the regular https://nodejs.org/download/release/ website.

Impact

Expected update tasks and impact will include:

• Documentation README references to support category and process
• Dockerfile-alpine.template to source the musl build from https://nodejs.org/download/release/
• update.sh script so that the -s (security) option does not exclude Alpine builds
• build-automation.mjs remove checks against https://unofficial-builds.nodejs.org

Review other Alpine-related issues and PR for relevance and applicability.