Project-Owned Rush Toolchain

Rush Delivery v0.9.1 lets a repository add deterministic executables to the shared Rush workflow image through .dagger/toolchains/rush.yaml. The contract is intentionally narrow: immutable base image, checksummed HTTPS downloads, and fixed executable destinations. It is not a general container build script.

Projects without this file keep the exact existing Node-only toolchain spec, hash, provider cache reference, and provider-off behavior.

Contract

Use the exact versioned rush-toolchain schema. The same metadata is available as a tested configuration fragment:

# yaml-language-server: $schema=https://bootstraplaboratory.github.io/rush-delivery/schemas/v0.9.1/rush-toolchain.schema.json
version: rush-delivery-rush-toolchain/v1
base_image: node:24-bookworm-slim@sha256:65932751ed4073ed02f5c04e494e4b2572a891b7dbea0568a863dc80341bf848
platform: linux/amd64
downloads:
  - url: https://github.com/astral-sh/uv/releases/download/0.12.2/uv-x86_64-unknown-linux-gnu.tar.gz
    sha256: d66e96b5f1ca3b99806eee283a8125d33a0bd669e6e6d9bc4ab7ffda63c41bf4
    format: tar_gz
    archive_path: uv-x86_64-unknown-linux-gnu/uv
    destination: /usr/local/bin/uv
    mode: "0755"

The configured base must be digest-pinned Linux/amd64 and provide Bash, Node.js 24, apt-get, and the Debian behavior needed by the standard Rush bootstrap. The supported pattern is a pinned node:24-bookworm-slim image. Rush Delivery runs capability/version preflight before contacting project download URLs.

Each of 1–16 ordered downloads has:

• an HTTPS URL without userinfo, query, fragment, credentials, or interpolation;
• a lowercase SHA-256 digest;
• raw or tar_gz format;
• one normalized archive_path exactly when using tar_gz;
• a unique direct child of /usr/local/bin as its destination; and
• executable mode fixed to the string "0755".

See the schema for the exact syntax. Unknown fields are rejected. Shells, commands, environment maps, package-manager hooks, arbitrary destinations, and secret injection are not part of this metadata version.

Download And Extraction Guarantees

Rush Delivery transfers each URL in a framework-owned, digest-pinned helper container. It enforces HTTPS on the first request and every redirect, at most five redirects, a 30-second connection timeout, a 300-second total timeout, and a 256 MiB compressed-byte limit.

The declared SHA-256 is verified before extraction or installation. For a tar archive, the named member must occur exactly once, be a regular file rather than a link, and declare no more than 256 MiB before extraction. The extracted file is checked again for regular-file/link status and size, then copied to its fixed destination with mode 0755.

Download data never becomes a module-process string. No workflow/deploy host environment, runtime file, application-image provider value, or arbitrary secret is supplied to project toolchain construction.

Lifecycle And Cache Identity

Configured metadata produces rush-delivery-toolchain-image/v2. The toolchain image hash includes metadata version, pinned base, platform, and every field of every download in order, plus the framework's fixed Rush bootstrap. Reordering downloads or changing any checksum changes the cache reference.

The installed tools are available before Rush install, Detect, Build, validation, Rush-requiring Package work, and npm package Release. OCI-only Package work does not construct a Rush toolchain it does not use.

Provider behavior remains the same:

• provider off builds the configured image in the current Dagger run;
• github with lazy pulls by spec hash, builds on miss, and publishes after a trusted successful path; and
• github with pull-or-build pulls or builds locally without publishing.

Toolchain-provider registry credentials remain explicit framework capabilities. They do not become toolchain environment variables and are never hashed.

Safe Update Procedure

1. Select the upstream release and linux/amd64 asset from an authenticated operator workstation.

2. Download the asset independently and calculate SHA-256. Do not copy a digest from an untrusted mirror or from the same transport without verification.

3. For tar_gz, list the archive and record the exact regular-file member.

4. Update URL, checksum, archive path, and destination together in a reviewed change.

5. Validate metadata before a build:

   dagger -m github.com/BootstrapLaboratory/rush-delivery@v0.9.1 \
     call validate-metadata-contract --repo=.

6. Run a provider-off validation and assert the tool's version before the first package command that needs it.

7. In a trusted non-production run, use the normal lazy toolchain provider to populate the new content-addressed cache. PR jobs can then use pull-or-build without write permission.

8. Promote the same reviewed metadata to production. Do not copy a cache tag between different metadata hashes.

Failure Guide

Failure	Meaning	Operator action
Base preflight fails	The selected base is outside the Node 24 Debian contract	Choose a supported digest-pinned base; do not add arbitrary bootstrap commands
HTTPS/redirect/timeout/size failure	Transfer did not satisfy framework bounds	Verify upstream availability and asset size; mirror only under an approved HTTPS origin and update the URL/checksum together
Checksum mismatch	Downloaded bytes are not the reviewed asset	Stop; inspect upstream provenance or compromise before changing the digest
Member missing/duplicated/not regular	Archive layout or type is unsafe or changed	Inspect the new archive independently and update to one exact regular member
Tool missing in Rush scripts	Destination or selected metadata is wrong	Validate .dagger/toolchains/rush.yaml and run provider off to avoid a stale provider diagnosis
Provider auth error	Cache registry capability failed	Fix provider credentials/permissions; do not treat auth failure as a cache miss

Follow the mixed Node/Python tutorial for a complete first rollout and the upgrade guide for compatibility and recovery.