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check / check (push) Failing after 2s
Details
check always warns about files the manifest does not list (closes #103) 
check now always looks under the base directory for files the manifest
does not list, hidden files and directories included, and prints one
warning per file. The result still depends only on the listed files;
--no-extra-files turns each unlisted file into a failure, and --quiet
hides the warnings but not the failures. A directory that cannot be
listed is reported the same way, and the search goes on past it.

The manifest itself is left out by file identity, as gen and freshen
do; a symlink under the base is compared by what it points to. A base
directory named through a symlink is resolved before the search.

Model: opus-5-5
2026-10-04 17:48:51 +02:00

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# mfer
[mfer](https://git.eeqj.de/sneak/mfer) is a [WTFPL](https://wtfpl.net)-licensed
(public domain) [Go](https://golang.org) library and command-line tool by
[@sneak](https://sneak.berlin) that specifies and generates `.mf` manifest files
over a directory tree to encapsulate metadata about the files — such as
cryptographic checksums and signatures over same — to aid in archiving,
downloading, streaming, and mirroring. It was first published in 2022. The
manifest files' data is serialized with Google's
[protobuf serialization format](https://developers.google.com/protocol-buffers).
The structure of these files can be found
[in the format specification](https://git.eeqj.de/sneak/mfer/src/branch/main/mfer/mf.proto)
which is included in the [project repository](https://git.eeqj.de/sneak/mfer).
The current version is pre-1.0 and while the repo was published in 2022, there
has not yet been any versioned release. [SemVer](https://semver.org) will be
used for releases.
This project was started by [@sneak](https://sneak.berlin) to scratch an itch in
2022 and is currently a one-person effort, though the goal is for this to emerge
as a de-facto standard and be incorporated into other software. A compatible
javascript library is planned.
# Getting Started
`mfer` builds from source with a Go 1.23+ toolchain. The generated protobuf code
is committed, so no `protoc` toolchain is required:
```sh
git clone https://git.eeqj.de/sneak/mfer.git
cd mfer
go build -o bin/mfer ./cmd/mfer
```
Generate a manifest for a directory tree, verify it later, and fetch a published
tree by URL:
```sh
# Write index.mf, a manifest of the files under the current directory.
bin/mfer gen .
# Verify the files on disk against the manifest. Exits nonzero if any file
# it lists is missing or corrupted; warns about files it does not list.
bin/mfer check index.mf
# Download and cryptographically verify a tree published over HTTP: mfer
# fetches <url>/index.mf, then downloads every file it lists.
bin/mfer fetch https://example.com/tree/
```
Run `bin/mfer help` for the full command list, or `bin/mfer <command> --help`
for a single command's options.
# Build Status
CI runs `script/cibuild`, which builds the Docker image with `--no-cache`, so
the formatting, lint and test steps in the `Dockerfile` run on every build. The
`main` branch must always be green.
# Entrypoints
This repository adheres to the
[Scripts to Rule Them All](https://github.com/github/scripts-to-rule-them-all)
standard: normalized scripts in `script/` are the entrypoints for the
development workflow, and the Makefile targets are thin shims that call them. We
provide:
- `script/bootstrap` — install all dependencies (Go, Go module download, and
node/yarn plus the prettier version pinned in `package.json`/`yarn.lock`),
idempotently; golangci-lint is not installed, it runs only in Docker
- `script/setup` — make a fresh clone ready for development: runs
`script/bootstrap`, then `script/install-precommit`
- `script/projectname` — output the project name (`mfer`); used by other scripts
such as `script/docker`
- `script/test` — run the test suite (`go test`); one test fails when
`mfer/mf.proto` no longer matches the hash `script/generate` recorded
- `script/generate` (`make generate`) — regenerate `mfer/mf.pb.go` from
`mfer/mf.proto` and record the hash of that `mfer/mf.proto` in
`mfer/mf.proto.sha256`; the only thing that regenerates the committed
`mfer/mf.pb.go`. It needs the exact versions that wrote the committed file,
and refuses to run with any other: `protoc` 33.4 (unpack
`protoc-33.4-<platform>.zip` from
[its release](https://github.com/protocolbuffers/protobuf/releases/tag/v33.4)
and put its `bin/protoc` on `PATH`) and `protoc-gen-go` v1.36.11
(`go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.36.11`, which
installs it in `$(go env GOPATH)/bin`; `make generate` adds that directory to
`PATH`)
- `script/fuzz` — fuzz the manifest parser for one minute; run by hand
(`make fuzz`), never by CI, while `script/test` runs its committed seed corpus
as ordinary tests
- `script/lint` — run `golangci-lint` in Docker: builds only the `lint` stage of
the `Dockerfile` (the Go format check, then the linter), uncached so it runs
every time, then removes the image
- `script/fmt` — format all code and docs (writes): `gofumpt` and
`script/prettier --write`
- `script/prettier` — run prettier over the repository's canonical file set
(Markdown and JSON, minus `.prettierignore`) in the given mode, `--write` or
`--check`; the single definition of that file set, so `script/fmt` and
`script/fmt-check` cannot disagree about it
- `script/fmt-check` — check formatting without writing: `script/fmt-check-go`
plus `script/prettier --check`
- `script/fmt-check-go` — the Go half of `script/fmt-check`, on its own, for the
Docker lint stage, whose image has no node
- `script/check` — run `script/test`, `script/lint`, and `script/fmt-check`
- `script/docker` — build the Docker image tagged with the project name
- `script/cibuild` — CI entrypoint: builds the image with the same command as
`script/docker`, uncached, so the checks in the Dockerfile run every time
- `script/precommit` — pre-commit checks: `go mod tidy` verification, then
`script/check`
- `script/install-precommit` — install the git pre-commit hook that runs
`script/precommit`
# Participation
The community is as yet nonexistent so there are no defined policies or norms
yet. Primary development happens on a privately-run Gitea instance at
[https://git.eeqj.de/sneak/mfer](https://git.eeqj.de/sneak/mfer) and issues are
[tracked there](https://git.eeqj.de/sneak/mfer/issues).
Changes must always be formatted with a standard `go fmt`, syntactically valid,
and must pass the linting defined in the repository's `.golangci.yml`, which
`make lint` runs in Docker. The `main` branch is protected and all changes must
be made via [pull requests](https://git.eeqj.de/sneak/mfer/pulls) and pass CI to
be merged. Any changes submitted to this project must also be
[WTFPL-licensed](https://wtfpl.net) to be considered.
See [`REPO_POLICIES.md`](REPO_POLICIES.md) for detailed coding standards,
tooling requirements, and workflow conventions.
# Rationale
## The problem
Given a plain URL, there is no standard way to safely and programmatically
download everything "under" that URL path. `wget -r` can traverse directory
listings if they're enabled, but every server has a different format, and this
does not verify cryptographic integrity of the files, or enable them to be
fetched using a different protocol other than HTTP/s.
Currently, the solution that people are using are sidecar files in the format of
`SHASUMS` checksum files, as well as a `SHASUMS.asc` PGP detached signature.
This is not checksum-algorithm-agnostic and the sidecar file is not always
consistently named.
Real issues I face:
- when I plug in an ExFAT hard drive, I don't know if any files on the
filesystem are corrupted or missing
- current ad-hoc solution are `SHASUMS`/`SHASUMS.asc` files
- when I want to mirror an HTTP archive, I have to use special tools like
debmirror that understand the archive format
- the debian repository metadata structure is hot garbage
- when I download a large file via HTTP, I have no way of knowing if the file
content is what it's supposed to be
## The solution
A standard, a manifest file format, and a tool for generating same.
The manifest file would be called `index.mf`, and the tool for generating such
would be called `mfer`.
The manifest file would do several important things:
- have a standard filename, so if given `https://example.com/downloadpackage/`
one could fetch `https://example.com/downloadpackage/index.mf` to enumerate
the full directory listing.
- contain a version field for extensibility
- contain structured data (protobuf, json, or cbor)
- provide an inner signed container, so that the manifest file itself can embed
a signature and a public key alongside in a single file
- contain a list of files, each with a relative path to the manifest
- contain manifest timestamp
- contain ctime/mtime information for files so that file metadata can be
preserved
- contain cryptographic checksums in several different algorithms for each file
- probably encoded with multihash to indicate algo + hash
- sha256 at the minimum
- would be nice to include an IPFS/IPLD CIDv1 root hash for each file, which
likely involves doing an ipfs file object chunking
- maybe even including the complete IPFS/IPLD directory tree objects and
chunklists?
- this is because generating an `index.mf` does not imply publishing on
ipfs at that time
- maybe a bittorrent chunklist for torrent client compatibility? perhaps a
top-level infohash for the whole manifest?
# Design
The repository is split into a reusable library and a thin command-line wrapper
around it.
- `mfer/` is the reusable library and the heart of the project: it defines the
manifest format and implements building, scanning, checking, serialization,
and signing. The protobuf schema is `mfer/mf.proto`, and the generated code it
produces (`mfer/mf.pb.go`) is committed alongside it so the library builds
with `go get` and needs no `protoc` toolchain.
- `internal/cli/` holds the command implementations — `generate` (alias `gen`),
`check`, `freshen`, `export`, `list` (alias `ls`), `fetch`, and `version` —
that wire the library to the command-line interface.
- `internal/log/` provides the logging used by the commands and the library.
- `internal/bork/` provides the error the library returns when a manifest's
decompressed contents are not the size the manifest records.
- `cmd/mfer/` is the entrypoint: its `main` package runs `internal/cli` and
exits with the status it returns.
Everything under `internal/` is private to this repository; only the `mfer/`
package is intended for import by other software.
# Design Goals
- Replace SHASUMS/SHASUMS.asc files
- be easy to download/resume a whole directory tree published via HTTP
- be easy to use across protocols (given an HTTPS url, fetch manifest, then
download file contents via bittorrent or ipfs)
- not strongly coupled to HTTP use case, should not require special hosting,
content types, or HTTP headers being sent
# Non-Goals
- Manifest generation speed
- likely involves IPFS chunking, bittorrent chunking, and several different
cryptographic hash functions over the entirety of each and every file
- Small manifest file size (within reason)
- 30MiB files are "small" these days, given modern storage/bandwidth
- metadata size should not be used as an excuse to sacrifice utility (such
as providing checksums over each chunk of a large file)
# Original Design Questions
These were the open questions when the project started; open design questions
are now tracked only in the [issues](https://git.eeqj.de/sneak/mfer/issues).
- Should the manifest file include checksums of individual file chunks, or just
for the whole assembled file? If so, should the chunk size be fixed or
dynamic? Still open, on
[issue 81](https://git.eeqj.de/sneak/mfer/issues/81#issuecomment-118698).
- Should the manifest signature format be GnuPG signatures, or those from
OpenBSD's signify (of which there is a good
[golang implementation](https://github.com/frankbraun/gosignify))? Still open,
as question 10 on [issue 82](https://git.eeqj.de/sneak/mfer/issues/82).
- Should the on-disk serialization format be proto3 or json? Settled: it is
proto3, see `docs/FORMAT.md` and `mfer/mf.proto`.
# Tool Examples
- `mfer gen` / `mfer gen .`
- recurses under current directory and writes out an `index.mf`
- `mfer check` / `mfer check .`
- verifies checksums of all files in manifest, displaying error and exiting
nonzero if any files are missing or corrupted
- warns about each file under the base directory that the manifest does not
list, hidden files included; with `--no-extra-files` each one is a failure
instead
- `mfer fetch https://example.com/stuff/`
- fetches `/stuff/index.mf` and downloads all files listed in manifest,
optionally resuming any that already exist locally, and assures
cryptographic integrity of downloaded files.
# Implementation Plan
## Phase One:
- golang module for reusability/embedding
- golang module client providing `mfer` CLI
## Phase Two:
- ES6 or TypeScript module for reusability/embedding
- ES6/TypeScript module client providing `mfer.js` CLI
# Hopes And Dreams
- `aria2c https://example.com/manifestdirectory/`
- (fetches `https://example.com/manifestdirectory/index.mf`, downloads and
checksums all files, resumes any that exist locally already)
- `mfer fetch https://example.com/manifestdirectory/`
- a command line option to zero/omit mtime/ctime, as well as manifest timestamp,
and sort all directory listings so that manifest file generation is
deterministic/reproducible
- URL format
`mfer fetch https://exmaple.com/manifestdirectory/?key=5539AD00DE4C42F3AFE11575052443F4DF2A55C2`
to assert in the URL which PGP signing key should be used in the manifest, so
that shared URLs have a cryptographic trust root
- a "well-known" key in the manifest that maps well known keys (could reuse the
http spec) to specific file paths in the manifest.
- example: a `berlin.sneak.app.slideshow` key that maps to a json slideshow
config listing what image paths to show, and for how long, and in what
order
# Use Cases
## Web Images
I'd like to be able to put a bunch of images into a directory, generate a
manifest, and then point a slideshow client (such as an ambient display, or a
react app with the target directory in a query string arg) at that statically
hosted directory, and have it discover the full list of images available at that
URL.
## Software Distribution
I'd like to be able to download a whole tree of files available via HTTP
resumably by either HTTP or IPFS/BitTorrent without a .torrent file.
## Filesystem Archive Integrity
I use filesystems that don't include data checksums, and I would like a
cryptographically signed checksum file so that I can later verify that a set of
archive files have not been modified, none are missing, and that the checksums
have not been altered in storage by a second party.
## Filesystem-Independent Checksums
I would like to be able to plug in a hard drive or flash drive and, if there is
an `index.mf` in the root, automatically detect missing/corrupted files,
regardless of filesystem format.
# Collaboration
Please email [`sneak@sneak.berlin`](mailto:sneak@sneak.berlin) with your desired
username for an account on this Gitea instance.
# TODO
Open work, open design questions included, is tracked in this repo's issues:
[https://git.eeqj.de/sneak/mfer/issues](https://git.eeqj.de/sneak/mfer/issues).
# See Also
## Prior Art: Metalink
- [Metalink - Mozilla Wiki](https://wiki.mozilla.org/Metalink)
- [Metalink - Wikipedia](https://en.wikipedia.org/wiki/Metalink)
- [RFC 5854 - The Metalink Download Description Format](https://datatracker.ietf.org/doc/html/rfc5854)
- [RFC 6249 - Metalink/HTTP: Mirrors and Hashes](https://www.rfc-editor.org/rfc/rfc6249.html)
## Links
- Repo: [https://git.eeqj.de/sneak/mfer](https://git.eeqj.de/sneak/mfer)
- Issues:
[https://git.eeqj.de/sneak/mfer/issues](https://git.eeqj.de/sneak/mfer/issues)
# Author
- [@sneak](https://sneak.berlin)
# License
- [WTFPL](https://wtfpl.net)
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