SNMP switch (#9840)

* Initial support for SNMP switch

Supports setting integer values

* Resolves styling issues

* Updates requirements

* Remove commented out import

* Changes default community to private. Fixes linting errors.

* More linter fixes and bugfix in #state()

* Refactors the code to make it simpler.

.coveragerc

@@ -599,6 +599,7 @@ omit =
     homeassistant/components/switch/rainmachine.py
     homeassistant/components/switch/rest.py
     homeassistant/components/switch/rpi_rf.py
+    homeassistant/components/switch/snmp.py
     homeassistant/components/switch/tplink.py
     homeassistant/components/switch/telnet.py
     homeassistant/components/switch/transmission.py

homeassistant/components/switch/snmp.py

@@ -0,0 +1,150 @@
+"""
+Support for SNMP enabled switch.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/switch.snmp/
+"""
+
+import logging
+
+import voluptuous as vol
+
+from homeassistant.components.switch import (SwitchDevice, PLATFORM_SCHEMA)
+from homeassistant.const import (CONF_HOST, CONF_NAME, CONF_PORT,
+                                 CONF_PAYLOAD_ON, CONF_PAYLOAD_OFF)
+import homeassistant.helpers.config_validation as cv
+
+REQUIREMENTS = ['pysnmp==4.3.10']
+
+_LOGGER = logging.getLogger(__name__)
+
+CONF_BASEOID = 'baseoid'
+CONF_COMMUNITY = 'community'
+CONF_VERSION = 'version'
+
+DEFAULT_NAME = 'SNMPSwitch'
+DEFAULT_HOST = 'localhost'
+DEFAULT_PORT = '161'
+DEFAULT_COMMUNITY = 'private'
+DEFAULT_VERSION = '1'
+DEFAULT_PAYLOAD_ON = 1
+DEFAULT_PAYLOAD_OFF = 0
+
+SNMP_VERSIONS = {
+    '1': 0,
+    '2c': 1
+}
+
+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_VERSION, default=DEFAULT_VERSION):
+        vol.In(SNMP_VERSIONS),
+    vol.Optional(CONF_PAYLOAD_ON, default=DEFAULT_PAYLOAD_ON): cv.string,
+    vol.Optional(CONF_PAYLOAD_OFF, default=DEFAULT_PAYLOAD_OFF): cv.string
+})
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Set up the SNMP switch."""
+    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)
+    version = config.get(CONF_VERSION)
+    payload_on = config.get(CONF_PAYLOAD_ON)
+    payload_off = config.get(CONF_PAYLOAD_OFF)
+
+    add_devices([SnmpSwitch(name, host, port, community,
+                            baseoid, version, payload_on,
+                            payload_off)], True)
+
+
+class SnmpSwitch(SwitchDevice):
+    """Represents a SNMP switch."""
+
+    def __init__(self, name, host, port, community,
+                 baseoid, version, payload_on, payload_off):
+        """Initialize the switch."""
+        self._name = name
+        self._host = host
+        self._port = port
+        self._community = community
+        self._baseoid = baseoid
+        self._version = SNMP_VERSIONS[version]
+        self._state = None
+        self._payload_on = payload_on
+        self._payload_off = payload_off
+
+    def turn_on(self):
+        """Turn on the switch."""
+        from pyasn1.type.univ import (Integer)
+
+        self._set(Integer(self._payload_on))
+
+    def turn_off(self):
+        """Turn off the switch."""
+        from pyasn1.type.univ import (Integer)
+
+        self._set(Integer(self._payload_off))
+
+    def update(self):
+        """Update the state."""
+        from pysnmp.hlapi import (
+            getCmd, CommunityData, SnmpEngine, UdpTransportTarget, ContextData,
+            ObjectType, ObjectIdentity)
+
+        from pyasn1.type.univ import (Integer)
+
+        request = getCmd(
+            SnmpEngine(),
+            CommunityData(self._community, mpModel=self._version),
+            UdpTransportTarget((self._host, self._port)),
+            ContextData(),
+            ObjectType(ObjectIdentity(self._baseoid))
+        )
+
+        errindication, errstatus, errindex, restable = next(request)
+
+        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:
+                if resrow[-1] == Integer(self._payload_on):
+                    self._state = True
+                elif resrow[-1] == Integer(self._payload_off):
+                    self._state = False
+                else:
+                    self._state = None
+
+    @property
+    def name(self):
+        """Return the switch's name."""
+        return self._name
+
+    @property
+    def is_on(self):
+        """Return true if switch is on; False if off. None if unknown."""
+        return self._state
+
+    def _set(self, value):
+        from pysnmp.hlapi import (
+            setCmd, CommunityData, SnmpEngine, UdpTransportTarget, ContextData,
+            ObjectType, ObjectIdentity)
+
+        request = setCmd(
+            SnmpEngine(),
+            CommunityData(self._community, mpModel=self._version),
+            UdpTransportTarget((self._host, self._port)),
+            ContextData(),
+            ObjectType(ObjectIdentity(self._baseoid), value)
+        )
+
+        next(request)

requirements_all.txt

@@ -764,6 +764,7 @@ pysma==0.1.3
 
 # homeassistant.components.device_tracker.snmp
 # homeassistant.components.sensor.snmp
+# homeassistant.components.switch.snmp
 pysnmp==4.3.10
 
 # homeassistant.components.sensor.thinkingcleaner