sysrepo-python-plugind 1.0.0

Python plugin daemon for sysrepo (replacement for sysrepo-plugind)

A Python reimplementation of sysrepo-plugind — the sysrepo plugin daemon.

The C daemon loads compiled .so plugins via dlopen. This daemon loads Python plugins discovered via entry points (importlib.metadata), giving plugin authors a pure-Python development experience against the existing sysrepo-python CFFI bindings.

The two daemons can run simultaneously: the Python daemon manages its own YANG subtree (python-plugin-order, python-loaded-plugins) and never touches the C daemon’s nodes.

Requirements

• Python ≥ 3.10

• sysrepo-python (and the underlying libsysrepo.so)

• sysrepo core 4.2.10 (ships [e-mail])

Installation

pip install sysrepo-python-plugind

Then register the YANG augmentation module with sysrepo (requires write access to the sysrepo repository, typically run as root):

sysrepo-python-plugind-setup

This is idempotent — safe to run on every deployment or system boot. Pass --force to upgrade the module after a package update.

Writing a plugin

Subclass SysrepoPlugin and implement init(). Register the class via an entry point in your package’s pyproject.toml:

[project.entry-points."sysrepo_python.plugins"]
my-plugin = "my_package.plugin:MyPlugin"

Installing your package makes the plugin visible to the daemon immediately — no copying of files or environment variables required.

Minimal example:

import logging
import sysrepo
from sysrepo_python_plugind import SysrepoPlugin

LOG = logging.getLogger(__name__)

class MyPlugin(SysrepoPlugin):

    def init(self, session: sysrepo.SysrepoSession) -> None:
        self._counter = 0
        session.subscribe_module_change(
            "my-module", None, self._on_change, done_only=True
        )
        session.subscribe_oper_data_request(
            "my-module", "/my-module:stats", self._on_oper
        )
        LOG.info("MyPlugin ready")

    def cleanup(self, session: sysrepo.SysrepoSession) -> None:
        LOG.info("MyPlugin stopping (counter=%d)", self._counter)

    def _on_change(self, event, req_id, changes, priv):
        self._counter += 1

    def _on_oper(self, xpath, priv):
        return {"my-module": {"stats": {"change-count": self._counter}}}

State that the C daemon stored in void *private_data is stored as instance attributes (self._counter above).

Async callbacks

The daemon starts an asyncio event loop in a background thread before calling any init(), so plugins can use asyncio_register=True subscriptions without managing a loop themselves:

class AsyncMyPlugin(SysrepoPlugin):

    def init(self, session: sysrepo.SysrepoSession) -> None:
        session.subscribe_module_change(
            "my-module", None, self._on_change,
            done_only=True, asyncio_register=True,
        )

    async def _on_change(self, event, req_id, changes, priv):
        ...

Running the daemon

# Foreground, INFO-level logging to stderr:
sysrepo-python-plugind -d -v 2

# Background (daemonize), write PID file:
sysrepo-python-plugind -p /run/sysrepo-python-plugind.pid

CLI flags mirror those of the C sysrepo-plugind:

-d	Stay in foreground; log to stderr instead of syslog
-v LEVEL	Verbosity: 0=ERROR 1=WARNING 2=INFO 3=DEBUG (default: 2)
-p PATH	Write PID file at PATH
-f	Exit if any plugin fails to initialise (default: skip and continue)

Plugin ordering

By default plugins are initialised in entry-point discovery order. To override this, set the python-plugin-order leaf-list in sysrepo’s running datastore:

sysrepocfg -d running --edit

Add under /sysrepo-plugind:sysrepo-plugind:

<python-plugin-order xmlns="urn:sysrepo:python-plugind">
  <plugin>my-plugin</plugin>
  <plugin>other-plugin</plugin>
</python-plugin-order>

Plugins absent from the list are appended after the ordered set, preserving their discovery order. A trailing file extension in a configured name (e.g. my-plugin.so) is stripped before comparison, so operator configs written for the C daemon can be reused unchanged.

The list of successfully initialised plugins is published to the operational datastore at /sysrepo-plugind:sysrepo-plugind/sysrepo-python-plugind:python-loaded-plugins/plugin.

Systemd deployment

A service file is provided in the systemd/ directory of the source distribution:

cp systemd/sysrepo-python-plugind.service /etc/systemd/system/
systemctl daemon-reload
systemctl enable --now sysrepo-python-plugind

The service runs sysrepo-python-plugind-setup as ExecStartPre=, ensuring the YANG module is present before the daemon starts.

If the daemon binary is not at /usr/bin/sysrepo-python-plugind (e.g. when installed into a virtual environment), update the ExecStartPre= and ExecStart= paths in the service file accordingly.

License

BSD-3-Clause — same as sysrepo-python.