Muamba

Muamba vendors remote files using trust on first use (TOFU). Running lock accepts the first response returned by each reviewed URL and records its SHA-384 digest in muamba.yaml. The digest detects later changes; it does not authenticate the publisher or content. verify checks materialized files offline. sync restores missing or corrupt files only when available bytes match the lock.

Muamba treats every download as opaque bytes. It works with JavaScript, CSS, licenses, notices, source maps, executables, and other release files without package-manager rules. Once you commit the manifest and files, builds and tests need no network access.

Requirements and installation

Muamba requires Go 1.26.5 or later. Add the current release to a consumer module as a pinned Go tool:

go get -tool github.com/araihu/muamba/cmd/muamba@v0.0.2
go tool muamba help

Use go run ./cmd/muamba when working in this repository.

Manifest

Each resource groups related downloads under one version. Every download names a destination path and either a base URL or platform-specific URLs:

schema: 1

resources:
  bootstrap:
    version: "5.3.8"
    downloads:
      bundle-js:
        url: https://unpkg.com/bootstrap@${version}/dist/js/bootstrap.bundle.min.js
        path: assets/vendor/bootstrap/${version}/bootstrap.bundle.min.js
      core-css:
        url: https://unpkg.com/bootstrap@${version}/dist/css/bootstrap.min.css
        path: assets/vendor/bootstrap/${version}/bootstrap.min.css
      license:
        url: https://unpkg.com/bootstrap@${version}/LICENSE
        path: assets/vendor/bootstrap/${version}/LICENSE

${version} is the only template token. It works in url and path. Muamba warns when an expanded URL omits the exact declared version. With --strict, that warning stops the command before any download or write.

The manifest records download mechanics, not generic metadata. Keep consumer-specific roles, licensing relationships, attribution, and overlays outside Muamba.

Platform-aware executables

Downloads default to platform: multi, which suits JavaScript, CSS, licenses, and similar files. Declare an exact Go target when a download works on only one platform:

resources:
  tool:
    version: "1.2.3"
    downloads:
      cli:
        url: https://example.com/v${version}/tool-linux-x64
        path: .tools/tool
        platform: linux/amd64
        executable: true
        max_size: 128MiB

Use an exact platform map when a release publishes one executable per target. All variants share one destination path:

resources:
  tailwind:
    version: "4.3.3"
    downloads:
      cli:
        path: .tools/tailwindcss
        executable: true
        max_size: 128MiB
        platforms:
          linux/amd64:
            url: https://github.com/tailwindlabs/tailwindcss/releases/download/v${version}/tailwindcss-linux-x64
            integrity: sha384-...
          darwin/arm64:
            url: https://github.com/tailwindlabs/tailwindcss/releases/download/v${version}/tailwindcss-macos-arm64
            integrity: sha384-...

url is optional when platforms is present. An exact platform entry takes precedence over a compatible base URL. Otherwise, a base URL applies when platform is multi or matches the target. Target names use exact Go GOOS/GOARCH values. Unsupported targets fail before downloads or destination writes. Muamba does not infer aliases or libc variants.

executable defaults to false. Materialized executables use mode 0755; other files use 0644 on POSIX. max_size accepts positive binary sizes using KiB, MiB, or GiB; omission retains the 100 MiB default.

Trust and materialization workflow

Check the committed example in this repository without network access:

go run ./cmd/muamba verify --strict -f examples/web-assets/muamba.yaml

For a new or partially unlocked manifest, review every URL before you establish first trust:

go tool muamba lock --strict

lock downloads every unlocked base URL and platform variant, caches the first fetched bytes, and adds their SHA-384 SRI locks to the same YAML atomically. It writes only the selected target to each shared destination. Use --target GOOS/GOARCH to choose another target. Commit the manifest and tracked downloads together.

Later commands reject different bytes:

# Offline, read-only integrity check.
go tool muamba verify --strict

# Restore missing or corrupt files only when remote bytes match the lock.
go tool muamba sync --strict

# Restore a CI target explicitly.
go tool muamba sync --strict --target linux/amd64

# Operate on one resource or download.
go tool muamba verify --strict bootstrap/core-css

# Offline verification of every locked cache blob.
go tool muamba verify --strict --all-platforms

Trust changes only through an explicit update. Move every download in a grouped resource atomically to a new logical version:

go tool muamba update bootstrap --version 5.3.9 --strict

Or re-trust one artifact whose bytes changed at the same URL:

go tool muamba update bootstrap/core-css --strict

A grouped or single-download update stages and hashes every declared platform variant before it changes the manifest or visible files. It materializes only the selected target. If an old versioned file no longer matches its previous lock, Muamba leaves it in place and fails the update.

Commands search the current directory and its parents for muamba.yaml. Pass -f PATH to select one explicitly. Selectors are resource or resource/download; no selector means all downloads.

Integrity cache and CI

Every locked download can use the integrity cache, including JavaScript, CSS, licenses, and executables. The cache key is the parsed algorithm plus digest. URL, resource name, and version do not affect identity, so identical locked bytes share one blob. Muamba verifies cached bytes before every use.

Muamba resolves the cache directory from --cache-dir, then MUAMBA_CACHE_DIR, then the muamba child of the operating system user cache directory. sync follows this order:

1. Verify the destination; seed or repair its cache blob without network.
2. Otherwise verify and copy the cache blob atomically.
3. Otherwise download, verify, cache, and atomically materialize it.

Corrupt cached or remote bytes never replace an existing destination. Muamba uses regular copies instead of symlinks or hard links.

GitHub Actions can persist a repository-local cache while keeping executable destinations ignored:

- uses: actions/cache@v4
  with:
    path: .cache/muamba
    key: muamba-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('muamba.yaml') }}

- run: go tool muamba sync --strict --target linux/amd64 --cache-dir .cache/muamba

Generate embedded Go resources

Run generate-go once for each Go package that owns vendored files:

go run ./cmd/muamba generate-go \
  --strict \
  --target linux/amd64 \
  -f examples/web-assets/muamba.yaml \
  --dir assets \
  --output muamba_gen.go

go run ./cmd/muamba generate-go \
  --strict --check \
  -f examples/web-assets/muamba.yaml \
  --dir assets \
  --output muamba_gen.go

--dir is relative to the manifest. Generation selects locked downloads under that package directory, verifies their local bytes, emits explicit //go:embed paths, and formats deterministic Go. It infers the package from an existing non-test .go file. Use --package NAME for an otherwise empty package directory. Generation uses the runtime target by default. Projects that commit platform-specific generated bytes should always pass --target.

The generated API exposes resource and download types plus four lookup functions:

type MuambaDownload struct {
	Name      string
	URL       string
	Path      string
	Integrity string
	Hash      string
}

func MuambaResources() []MuambaResource
func MuambaResourceByName(name string) (MuambaResource, bool)
func MuambaHash(resource, download string) (string, bool)
func MuambaOpen(resource, download string) (fs.File, error)

Integrity preserves the manifest’s original SRI or hexadecimal spelling. Hash is the same full digest normalized as sha256|sha384|sha512:<lowercase-hex>, independent of the manifest encoding. Consumers can use the field or direct lookup for cache busting:

hash, ok := MuambaHash("bootstrap", "core-css")
if !ok {
	return errors.New("bootstrap/core-css is not embedded")
}
stylesheetURL := "/assets/bootstrap.css?v=" + url.QueryEscape(hash)

Muamba exposes the complete digest. The consumer owns URL shape, query names, and cache headers.

Generated resource/download constants and the embedded filesystem stay private. Projects needing several package directories run generate-go once per package. See examples/web-assets for a committed JS, CSS, and license example.

Integrity and transport policy

Muamba accepts SRI Base64 and prefixed hexadecimal integrity values using SHA-256, SHA-384, or SHA-512:

sha384-BASE64
sha256:HEX

New locks use SHA-384 SRI. HTTPS is the default. Riskier transport requires an explicit option:

--allow-http
--insecure-skip-tls-verify
--ca-file private-ca.pem
--timeout 30s
--max-size 10485760
--target linux/amd64
--cache-dir .cache/muamba

An explicit --max-size byte count overrides every manifest max_size for that invocation. Otherwise each download's declared limit applies before the 100 MiB default.

Allowing HTTP does not disable TLS verification for HTTPS. Muamba checks each redirect target, caps redirects at ten, and never includes response bodies in errors.

Scope and roadmap

Muamba v1 excludes authentication, SSH/Git sources, archive extraction, release discovery, overlays, attribution models, and automatic network access during build or test.

Planned source access includes HTTP Basic authentication, bearer/JWT tokens, OAuth 2.0 client credentials, and SSH. Credential values will come from environment variables, keychains, agents, or helper processes. They will not live in muamba.yaml. Other roadmap candidates include protected credential redirects, Git/release discovery, safe archive extraction, resumable downloads, bounded parallelism, cache inspection and eviction, musl targeting, platform aliases, and multiple materialization destinations. Muamba remains publisher-neutral and does not hardcode release knowledge for Tailwind or other projects.

Development

go mod tidy
gofmt_files="$(gofmt -l .)" || exit 1
test -z "$gofmt_files"
go vet ./...
golangci-lint run
scripts/check-coverage_test.sh
scripts/check-coverage.sh
go test -race ./...
go run ./cmd/muamba verify --strict -f examples/web-assets/muamba.yaml
go run ./cmd/muamba generate-go --strict --check \
  -f examples/web-assets/muamba.yaml --dir assets --output muamba_gen.go

Coverage must remain at or above 70%; CI uploads the raw profile, function summary, and HTML report. See CONTRIBUTING.md before opening a pull request. Report vulnerabilities privately using SECURITY.md.