core/homeassistant/components/sensor/snmp.py

136 lines
4.3 KiB
Python

"""
Support for displaying collected data over SNMP.
For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/sensor.snmp/
"""
import logging
from datetime import timedelta
import voluptuous as vol
from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.helpers.entity import Entity
from homeassistant.const import (
CONF_HOST, CONF_NAME, CONF_PORT, CONF_UNIT_OF_MEASUREMENT)
import homeassistant.helpers.config_validation as cv
from homeassistant.util import Throttle
REQUIREMENTS = ['pysnmp==4.3.2']
_LOGGER = logging.getLogger(__name__)
CONF_BASEOID = 'baseoid'
CONF_COMMUNITY = 'community'
DEFAULT_COMMUNITY = 'public'
DEFAULT_HOST = 'localhost'
DEFAULT_NAME = 'SNMP'
DEFAULT_PORT = '161'
MIN_TIME_BETWEEN_UPDATES = timedelta(seconds=10)
PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
vol.Required(CONF_BASEOID): cv.string,
vol.Optional(CONF_COMMUNITY, default=DEFAULT_COMMUNITY): cv.string,
vol.Optional(CONF_HOST, default=DEFAULT_HOST): cv.string,
vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
vol.Optional(CONF_PORT, default=DEFAULT_PORT): cv.port,
vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string,
})
def setup_platform(hass, config, add_devices, discovery_info=None):
"""Setup the SNMP sensor."""
from pysnmp.hlapi import (getCmd, CommunityData, SnmpEngine,
UdpTransportTarget, ContextData, ObjectType,
ObjectIdentity)
name = config.get(CONF_NAME)
host = config.get(CONF_HOST)
port = config.get(CONF_PORT)
community = config.get(CONF_COMMUNITY)
baseoid = config.get(CONF_BASEOID)
unit = config.get(CONF_UNIT_OF_MEASUREMENT)
errindication, _, _, _ = next(
getCmd(SnmpEngine(),
CommunityData(community, mpModel=0),
UdpTransportTarget((host, port)),
ContextData(),
ObjectType(ObjectIdentity(baseoid))))
if errindication:
_LOGGER.error('Please check the details in the configuration file')
return False
else:
data = SnmpData(host, port, community, baseoid)
add_devices([SnmpSensor(data, name, unit)])
class SnmpSensor(Entity):
"""Representation of a SNMP sensor."""
def __init__(self, data, name, unit_of_measurement):
"""Initialize the sensor."""
self.data = data
self._name = name
self._state = None
self._unit_of_measurement = unit_of_measurement
self.update()
@property
def name(self):
"""Return the name of the sensor."""
return self._name
@property
def state(self):
"""Return the state of the sensor."""
return self._state
@property
def unit_of_measurement(self):
"""Return the unit the value is expressed in."""
return self._unit_of_measurement
def update(self):
"""Get the latest data and updates the states."""
self.data.update()
self._state = self.data.value
class SnmpData(object):
"""Get the latest data and update the states."""
def __init__(self, host, port, community, baseoid):
"""Initialize the data object."""
self._host = host
self._port = port
self._community = community
self._baseoid = baseoid
self.value = None
@Throttle(MIN_TIME_BETWEEN_UPDATES)
def update(self):
"""Get the latest data from the remote SNMP capable host."""
from pysnmp.hlapi import (getCmd, CommunityData, SnmpEngine,
UdpTransportTarget, ContextData, ObjectType,
ObjectIdentity)
errindication, errstatus, errindex, restable = next(
getCmd(SnmpEngine(),
CommunityData(self._community, mpModel=0),
UdpTransportTarget((self._host, self._port)),
ContextData(),
ObjectType(ObjectIdentity(self._baseoid)))
)
if errindication:
_LOGGER.error("SNMP error: %s", errindication)
elif errstatus:
_LOGGER.error('SNMP error: %s at %s', errstatus.prettyPrint(),
errindex and restable[-1][int(errindex) - 1] or '?')
else:
for resrow in restable:
self.value = resrow[-1]