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 using the x64-musl build through cross-compilation

Update automation treats patch releases differently and proceeds with 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.