distributor/docs/internal/bundle.md

# Bundles

## Purpose

`internal/bundle` parses, discovers, and validates source bundles through the storage interface.

## Inputs and outputs

Input is a backend-rooted directory tree containing one or more `manifest.json` files. Output is a deterministic list of validated bundles with relative bundle paths and normalized manifest data.

## Manifest behavior

The source manifest requires:

- `schema_version: 1`
- `id`
- `digest`
- `created`
- non-empty `files`

Each file requires `path`, `sha256`, and `size`. Digests must use lowercase `sha256:<64 hex>` format. `created` must parse as RFC3339.

## Validation

`ValidateManifest` owns normalized source manifest semantics: schema version, id, digest format, timestamp presence, file list presence, source path safety, duplicate file paths, reserved paths, file digest format, non-negative file sizes, and the top-level bundle digest.

Storage-backed bundle validation additionally checks file existence, regular-file type, file size, and per-file SHA-256.

The bundle digest is SHA-256 of a deterministic JSON array of file records in manifest order with fields `path`, `sha256`, and `size`.

## Discovery

Discovery walks a storage backend beneath a source root, finds `manifest.json` files, sorts bundle paths lexically, and rejects nested manifests.

## Boundaries

Bundle code uses `internal/storage` and does not import local, SSH, or S3 adapters. CLI local path support is wired in `internal/app`.

## Tests

Before changing bundle behavior, inspect tests under `internal/bundle`.