ci: Route npm package restore through the Central Feed Service

[wenytang-ms]

Why

SFI Network Isolation requires build pipelines to stop restoring packages directly from public feeds. These pipelines resolve everything from registry.npmjs.org, so they cannot run on a network isolated pool, and they are flagged by the MountainPass SR21 campaign under ICM 840100965 (ServiceTree a7511cd0-e340-456b-892c-88ce9d7e37ec, deadline 2026-08-21).

This points npm at the CFS feed mseng/VSJava/vscjava.

How

The redirect is carried by npm_config_registry, declared as a pipeline variable. npm resolves configuration in the order

cli > environment > project .npmrc > user .npmrc > global > builtin > default

so writing the registry only into a generated user config leaves it at the second lowest precedence, outranked by anything the agent image already configures. Microsoft hosted images do ship a user level .npmrc pointing at an internal proxy. An environment variable sits above every .npmrc file, so it is the one lever that reaches all of these pipelines.

npm matches npm_config_* case insensitively, which matters because restore is not driven by a single task here — the Npm@1 tasks, npx json, npx @vscode/vsce and the vsce invocation inside AzureCLI@2 all inherit the agent environment rather than reading a task input.

A .npmrc is still generated into the agent temp directory, because NpmAuthenticate@0 discovers the registries to authenticate by reading it. npm now takes the URL from the environment and the matching credential from that file. Nothing is committed, so outside contributors and the GitHub Actions workflows keep restoring from the public registry, and the credential never lands inside the workspace.

The outcome is asserted, not assumed. A silent fallback to the public registry is the failure this change exists to prevent, and it leaves no trace in the build log — npm never reports which registry it used and the package counts look identical either way. In vscode-gradle this exact configuration produced a build that restored 718 packages against a CFS feed that had cached nothing. A Verify CFS npm registry step now fails the build if npm is not pointed at the feed by the time restore begins.

Template references are absolute and anchored to @self. A relative path is resolved against the file doing the including, which for these pipelines is the 1ES extends template in another repository, so the unqualified form is looked up in 1ESPipelineTemplates and fails YAML compilation.

Validation

Full template expansion through the pipelines preview API on this branch. No builds were queued.

Definition	Id	In SR21 scope	Preview
VSCode-Test-Runner-Pre-Release-Build	15770	yes	compiles
VSCode-Test-Runner-RC-Build	15776	yes	compiles
1ES-CI	15777	no	not previewable, definition disabled
microbuild-test	18848	no	not previewable, definition disabled
Java-Test-Runner-Release	21772	no	compiles
Java-Test-Runner-PreRelease	21773	no	compiles

Each passing pipeline expands to exactly three CFS steps — Configure CFS npm registry, Authenticate to CFS feed, Verify CFS npm registry — placed after the Node install task and before the first step that restores packages.

Feed authentication uses Project Collection Build Service (mseng), which holds contributor on the vscjava feed; all of these definitions run with jobAuthScope=projectCollection.

The verify script was also run directly under cmd.exe against both outcomes: with a preconfigured user .npmrc in effect it reports https://packagefeedproxy.microsoft.io/npm/ and exits 1, and with npm_config_registry set it reports the CFS feed and exits 0 — demonstrating the environment variable overriding a preconfigured user config, which is the case this change exists for.

Not covered

• NodeTool@0 / UseNode@1, JavaToolInstaller@0 and any APIScan tool download are separate outbound fetches and are not addressed here.
• The SR21 seven day lock-in cannot be satisfied by waiting on pipelines that are trigger: none or disabled.