nessie-backend-zfs

The ZFS-backed storage backend for nessie-store — the VolumeBackend ⊂ SnapshotBackend ⊂ CloneBackend stack mapped onto zfs/zpool/exportfs. Volumes are datasets, snapshots are zfs snapshot, FlexClones are zfs clone, and the data plane is an NFS export. Every command goes through a CommandRunner seam, so it is exact and testable.

Install

pip install nessie-backend-zfs      # Python
cargo add nessie-backend-zfs        # Rust

Usage (Python)

Two extension points. Outside — drive real ZFS (needs zfs/zpool + privilege):

from nessie_backend_zfs import ZfsBackend

b = ZfsBackend(pool="ontap-sim", data_lif="192.168.1.100")
vol = b.create_volume("build-cache", size_bytes=10 * 2**30)
snap = b.create_snapshot(vol["uuid"], "pre-build")
clone = b.create_clone(vol["uuid"], snap["uuid"], "build-cache-pr1234")
print(b.access_handle(vol["uuid"]))   # {'kind': 'nfs_export', 'server': ..., 'path': ...}

Inside — pass a runner(argv) -> {"success", "stdout", "stderr"} callable and every command is routed through your function. Mock it for tests, audit it, or wrap it in sudo:

from nessie_backend_zfs import ZfsBackend

def runner(argv):
    print("nessie ran:", " ".join(argv))      # audit every command
    return {"success": True, "stdout": "", "stderr": ""}

b = ZfsBackend(pool="tank", runner=runner)
vol = b.create_volume("vol1", size_bytes=1 << 30)   # prints: nessie ran: zfs create -o quota=...

Methods return plain dicts in the substrate-neutral domain shape and raise NessieError on failure.

Usage (Rust)

use nessie_backend_core::{VolumeBackend, VolumeSpec};
use nessie_backend_zfs::{SystemRunner, ZfsBackend, ZfsConfig};

let cfg = ZfsConfig { pool: "ontap-sim".into(), ..ZfsConfig::default() };
let b = ZfsBackend::new(SystemRunner, cfg);
let vol = b.create_volume(VolumeSpec::named("build-cache")).unwrap();

The CommandRunner trait is the same seam the Python runner rides on — swap SystemRunner for a mock to assert the exact argv in unit tests.

Dual-licensed MIT OR Apache-2.0.