python-sanlock

Python bindings for the sanlock library.

Originally developed as part of the sanlock project and used by oVirt/vdsm, this package is now maintained as a standalone module.

Requirements

Runtime

• sanlock >= 5.0.0 (sanlock-lib package on RHEL/Fedora)

Build

• Python >= 3.6
• gcc
• sanlock development headers (sanlock-devel on RHEL/Fedora)

On RHEL/Fedora:

dnf install gcc python3-devel sanlock-devel

Installation

pip install sanlock-python

Or from source:

pip install .

Usage

import sanlock

# Register with the sanlock daemon
fd = sanlock.register()

# Write a lockspace
sanlock.write_lockspace(b"my_lockspace", "/path/to/disk", iotimeout=10)

# Add the lockspace (acquire host_id)
sanlock.add_lockspace(b"my_lockspace", 1, "/path/to/disk")

# Write a resource
sanlock.write_resource(b"my_lockspace", b"my_resource", [("/path/to/disk", 0)])

# Acquire the resource
sanlock.acquire(b"my_lockspace", b"my_resource", [("/path/to/disk", 0)], slkfd=fd)

# Release the resource
sanlock.release(b"my_lockspace", b"my_resource", [("/path/to/disk", 0)], slkfd=fd)

# Remove the lockspace
sanlock.rem_lockspace(b"my_lockspace", 1, "/path/to/disk")

See example.py for a more complete example.

Testing

Tests require a running sanlock daemon and the pytest framework.

# Install test dependencies
pip install pytest userstorage

# Set up the environment
source tests/env.sh

# Run the tests
pytest tests/

To enable 4K sector tests, set up userstorage first:

userstorage create tests/storage.py
pytest tests/
userstorage delete tests/storage.py

License

GPL-2.0-or-later — see COPYING.