nix-daemon

A library for talking directly to the Nix Daemon.

Client Usage

To connect to a local nix-daemon, use a nix::DaemonStore (which implements the Store trait):

use nix_daemon::{Store, Progress, nix::DaemonStore};

let mut store = DaemonStore::builder()
    .connect_unix("/nix/var/nix/daemon-socket/socket")
    .await?;
let is_valid_path = store.is_valid_path("/nix/store/...").result().await?;

Server Usage

If you'd rather write your own nix-daemon compatible store, and expose it to existing tools like nix-build, you can implement the Store trait yourself and use nix::DaemonProtocolAdapter:

use tokio::net::UnixListener;
use nix_daemon::nix::{DaemonStore, DaemonProtocolAdapter};

// Accept a connection.
let listener = UnixListener::bind("/tmp/mystore.sock")?;
let (conn, _addr) = listener.accept().await?;

// This will just use `DaemonStore` to proxy to the normal daemon, but you can
// pass your own `Store` implementation here instead.
let mut store = DaemonStore::builder()
    .connect_unix("/nix/var/nix/daemon-socket/socket")
    .await?;

// Run the adapter!
let (cr, cw) = conn.into_split();
let mut adapter = DaemonProtocolAdapter::builder(&mut store)
    .adopt(cr, cw)
    .await?;

See nix-supervisor for a more complex example.

Limitations

• Not all opcodes are implemented (yet). Part of this is because in order to test them, we need to find somewhere they're actually used.
• Only Nix 2.15+ and Lix is supported at the moment, but support for 2.3 is high on the todo list. (And fairly easy to add.)

Contributing

Please see the main README.

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This project was funded through the NGI0 Entrust Fund, a fund established by NLnet with financial support from the European Commission's Next Generation Internet programme, under the aegis of DG Communications Networks, Content and Technology under grant agreement Nº 101069594.