nip is a git remote helper that'll put your repo's objects on IPFS - i.e. Nowhere In Particular.
Like with most Rust packages, the easiest way to install will be using Cargo:
$ cargo install nip
Important: Before you try to use nip please make sure that your local IPFS instance is running on its standard port.
Pushing an existing repo to a nip remote for the first time
$ git remote add nip nip::new-ipfs # Use a magic placeholder URL representing a new IPFS repo $ git push --all nip # Push all refs to a brand new repo INFO 2018-12-01T15:13:00Z: git_remote_nip: nip Remote nip moves onto a new hash: Previous: new-ipfs New: /ipfs/QmYn3tWpBKaTMgHY8F1cqDXwkHd5TGMqFpvX9ALqhD7Hew Full new repo address: nip::/ipfs/QmYn3tWpBKaTMgHY8F1cqDXwkHd5TGMqFpvX9ALqhD7Hew To nip::/ipfs/QmZq47khma5nP7DjHUPoERhKnfNUPqkr5pVwmS8A6TQSeN 1112e8f..aa89007 master -> master
Cloning a repo from nip
$ git clone nip::/ipfs/QmZq47khma5nP7DjHUPoERhKnfNUPqkr5pVwmS8A6TQSeN some_repo Cloning into 'some_repo'... $ ls some_repo some_file.txt some_other_file.txt $ git log commit 1112e8f58a9cfbe3a2cfba83ef302357dea266e7 (HEAD -> master, tag: some-new-tag, origin/master) Author: Stan Drozd <email@example.com> Date: Tue Nov 27 20:55:40 2018 +0100 Committing some_other_file.txt commit 99e9fc231cca0c2f8f70d3c5bac0170a2dfedabe Author: Stan Drozd <firstname.lastname@example.org> Date: Tue Nov 27 20:55:40 2018 +0100 Committing some_file.txt
Repo administration with nipctl (WIP)
nip comes with
nipctl - a utility for nip repo administration. It's nowhere
near ready yet, but you can view the list of planned features
here. Suggestions for additional
features are very welcome.
How it all works a.k.a. FAQ
How does git talk to nip?
nip implements what is called a git remote helper - a new remote transport
backend that can be used by git for pushes and fetches of remote git
repositories. In fact not so long ago the HTTP transport in git used to
be a separate binary taking advantage of this API. You can read more about the
exact remote helper operation in
Under the hood, the stuff above means that upon a
git push to or
git fetch from
a nip remote, git will run the
git-remote-nip binary and exchange information
about local/remote states via stdio. Then the binary is expected to carry out a
state sync as per the specification of the push/fetch.
How does nip interact with git repos and IPFS?
Locally, nip takes advantage of
git2-rs which is a set of Rust
libgit2 is then used to scoop
out or instantiate git objects - depending on whether a
operation is requested by git.
For IPFS storage nip uses a fairly thin CBOR-encoded format comprised of two
NIPIndex is what every top-level nip
repo IPFS link points to and effectively the face of every nip remote - it
stores information about all git objects available in a given remote as well as
where branch tips and tags should resolve to.
NIPObject on the other hand
captures the actual git object tree topology of the repo.
NIPObject is comprised of two parts:
- An IPFS link to the raw bytes of the underlying git object - this data isn't inlined within the data structure to maximize data deduplication, including objects produced by different nip versions or even different IPFS git backends that choose to operate in the same manner.
- git object-specific metadata - this is done via a helper enum type where the
variants contain differently arranged git hashes depending on object type:
- commits - parent hash(es), tree hash
- trees - children hashes (pointing to another nested tree or a blob)
- blobs - this variant is purely symbolic, the raw bytes link is sufficient since blobs are always leaf nodes in git
- tag objects - target object hash of the tag; only used for annotated/signed tags
A note on object tree edges in nip
An important fact about
NIPObject metadata is that the references to other
NIPObjects are git hashes and not IPFS ones - it is done that way so that the
Rust code can check if the local git repo already contains a given git object
without making any additional requests to the local IPFS node (it looks them up
NIPIndex which is always downloaded first). Also, this practice makes
the format less forgiving and therefore less prone to being incorrectly used.
How does nip intend to stay backwards-compatible?
Internally, nip prepends every serialized
NIPObject with a very
simple 8-byte header. It starts with a
b"NIPNIP" magic followed by a
big-endian 16-bit number denoting the version of the data format a given object
uses. This ensures that even when the serialization format is changed or even if
serde is no longer used,
nip will still be able to find out in time.
If you'd like to hack on nip, the
dev_bootstrap.sh script is where you should
start. It symlinks
~/.cargo/bin, respectively. As a result,
git-remote-nipdev for every remote that has a
- Repo pinning and git push notifications - people interested in keeping track of remote repo's progress have no way of knowing about pushes made to it. See this issue for progress on the solution.
- Submodules - nip doesn't understand how to push/pull submodule pins yet.
- Disk space - by design local git objects need to have IPFS counterparts which are kept in your local IPFS node's data store. In practice this means that every local object pushed to a nip repo needs to be stored on your disk again in a form that IPFS understands. However, nip guarantees object deduplication for all repos you use with it, which means a given git object is stored on IPFS only once, no matter the repo it comes from.
- Object size - nip doesn't know yet how to stream objects into/out of the local repository and will attempt to load them into RAM, this increases the memory footprint substantially for repos that posess large objects. Tracked here.
- Descriptor limits - Because of improper
tokiouse, currently nip may exceed descriptor limits because of redundant
tokioruntime instances. Tracked here. Easily solved by issuing
ulimit -n unlimitedjust before using git with a nip repo.