core/homeassistant/remote.py

547 lines
16 KiB
Python

"""
Support for an interface to work with a remote instance of Home Assistant.
If a connection error occurs while communicating with the API a
HomeAssistantError will be raised.
For more details about the Python API, please refer to the documentation at
https://home-assistant.io/developers/python_api/
"""
import asyncio
from datetime import datetime
import enum
import json
import logging
import time
import threading
import urllib.parse
from typing import Optional
import requests
import homeassistant.bootstrap as bootstrap
import homeassistant.core as ha
from homeassistant.const import (
HTTP_HEADER_HA_AUTH, SERVER_PORT, URL_API, URL_API_EVENT_FORWARD,
URL_API_EVENTS, URL_API_EVENTS_EVENT, URL_API_SERVICES, URL_API_CONFIG,
URL_API_SERVICES_SERVICE, URL_API_STATES, URL_API_STATES_ENTITY,
HTTP_HEADER_CONTENT_TYPE, CONTENT_TYPE_JSON)
from homeassistant.exceptions import HomeAssistantError
METHOD_GET = "get"
METHOD_POST = "post"
METHOD_DELETE = "delete"
_LOGGER = logging.getLogger(__name__)
class APIStatus(enum.Enum):
"""Represent API status."""
# pylint: disable=no-init,invalid-name,too-few-public-methods
OK = "ok"
INVALID_PASSWORD = "invalid_password"
CANNOT_CONNECT = "cannot_connect"
UNKNOWN = "unknown"
def __str__(self) -> str:
"""Return the state."""
return self.value
class API(object):
"""Object to pass around Home Assistant API location and credentials."""
# pylint: disable=too-few-public-methods
def __init__(self, host: str, api_password: Optional[str]=None,
port: Optional[int]=None, use_ssl: bool=False) -> None:
"""Initalize the API."""
self.host = host
self.port = port or SERVER_PORT
self.api_password = api_password
if use_ssl:
self.base_url = "https://{}:{}".format(host, self.port)
else:
self.base_url = "http://{}:{}".format(host, self.port)
self.status = None
self._headers = {
HTTP_HEADER_CONTENT_TYPE: CONTENT_TYPE_JSON,
}
if api_password is not None:
self._headers[HTTP_HEADER_HA_AUTH] = api_password
def validate_api(self, force_validate: bool=False) -> bool:
"""Test if we can communicate with the API."""
if self.status is None or force_validate:
self.status = validate_api(self)
return self.status == APIStatus.OK
def __call__(self, method, path, data=None, timeout=5):
"""Make a call to the Home Assistant API."""
if data is not None:
data = json.dumps(data, cls=JSONEncoder)
url = urllib.parse.urljoin(self.base_url, path)
try:
if method == METHOD_GET:
return requests.get(
url, params=data, timeout=timeout, headers=self._headers)
else:
return requests.request(
method, url, data=data, timeout=timeout,
headers=self._headers)
except requests.exceptions.ConnectionError:
_LOGGER.exception("Error connecting to server")
raise HomeAssistantError("Error connecting to server")
except requests.exceptions.Timeout:
error = "Timeout when talking to {}".format(self.host)
_LOGGER.exception(error)
raise HomeAssistantError(error)
def __repr__(self) -> str:
"""Return the representation of the API."""
return "API({}, {}, {})".format(
self.host, self.api_password, self.port)
class HomeAssistant(ha.HomeAssistant):
"""Home Assistant that forwards work."""
# pylint: disable=super-init-not-called,too-many-instance-attributes
def __init__(self, remote_api, local_api=None, loop=None):
"""Initalize the forward instance."""
if not remote_api.validate_api():
raise HomeAssistantError(
"Remote API at {}:{} not valid: {}".format(
remote_api.host, remote_api.port, remote_api.status))
self.remote_api = remote_api
self.loop = loop or asyncio.get_event_loop()
self.pool = pool = ha.create_worker_pool()
self.bus = EventBus(remote_api, pool, self.loop)
self.services = ha.ServiceRegistry(self.bus, self.add_job, self.loop)
self.states = StateMachine(self.bus, self.loop, self.remote_api)
self.config = ha.Config()
self.state = ha.CoreState.not_running
self.config.api = local_api
def start(self):
"""Start the instance."""
# Ensure a local API exists to connect with remote
if 'api' not in self.config.components:
if not bootstrap.setup_component(self, 'api'):
raise HomeAssistantError(
'Unable to setup local API to receive events')
self.state = ha.CoreState.starting
ha.create_timer(self)
self.bus.fire(ha.EVENT_HOMEASSISTANT_START,
origin=ha.EventOrigin.remote)
# Ensure local HTTP is started
self.block_till_done()
self.state = ha.CoreState.running
time.sleep(0.05)
# Setup that events from remote_api get forwarded to local_api
# Do this after we are running, otherwise HTTP is not started
# or requests are blocked
if not connect_remote_events(self.remote_api, self.config.api):
raise HomeAssistantError((
'Could not setup event forwarding from api {} to '
'local api {}').format(self.remote_api, self.config.api))
def stop(self):
"""Stop Home Assistant and shuts down all threads."""
_LOGGER.info("Stopping")
self.state = ha.CoreState.stopping
self.bus.fire(ha.EVENT_HOMEASSISTANT_STOP,
origin=ha.EventOrigin.remote)
self.pool.stop()
# Disconnect master event forwarding
disconnect_remote_events(self.remote_api, self.config.api)
self.state = ha.CoreState.not_running
class EventBus(ha.EventBus):
"""EventBus implementation that forwards fire_event to remote API."""
# pylint: disable=too-few-public-methods
def __init__(self, api, pool, loop):
"""Initalize the eventbus."""
super().__init__(pool, loop)
self._api = api
def fire(self, event_type, event_data=None, origin=ha.EventOrigin.local):
"""Forward local events to remote target.
Handles remote event as usual.
"""
# All local events that are not TIME_CHANGED are forwarded to API
if origin == ha.EventOrigin.local and \
event_type != ha.EVENT_TIME_CHANGED:
fire_event(self._api, event_type, event_data)
else:
super().fire(event_type, event_data, origin)
class EventForwarder(object):
"""Listens for events and forwards to specified APIs."""
def __init__(self, hass, restrict_origin=None):
"""Initalize the event forwarder."""
self.hass = hass
self.restrict_origin = restrict_origin
# We use a tuple (host, port) as key to ensure
# that we do not forward to the same host twice
self._targets = {}
self._lock = threading.Lock()
self._unsub_listener = None
def connect(self, api):
"""Attach to a Home Assistant instance and forward events.
Will overwrite old target if one exists with same host/port.
"""
with self._lock:
if self._unsub_listener is None:
self._unsub_listener = self.hass.bus.listen(
ha.MATCH_ALL, self._event_listener)
key = (api.host, api.port)
self._targets[key] = api
def disconnect(self, api):
"""Remove target from being forwarded to."""
with self._lock:
key = (api.host, api.port)
did_remove = self._targets.pop(key, None) is None
if len(self._targets) == 0:
# Remove event listener if no forwarding targets present
self._unsub_listener()
self._unsub_listener = None
return did_remove
def _event_listener(self, event):
"""Listen and forward all events."""
with self._lock:
# We don't forward time events or, if enabled, non-local events
if event.event_type == ha.EVENT_TIME_CHANGED or \
(self.restrict_origin and event.origin != self.restrict_origin):
return
for api in self._targets.values():
fire_event(api, event.event_type, event.data)
class StateMachine(ha.StateMachine):
"""Fire set events to an API. Uses state_change events to track states."""
def __init__(self, bus, loop, api):
"""Initalize the statemachine."""
super().__init__(bus, loop)
self._api = api
self.mirror()
bus.listen(ha.EVENT_STATE_CHANGED, self._state_changed_listener)
def remove(self, entity_id):
"""Remove the state of an entity.
Returns boolean to indicate if an entity was removed.
"""
return remove_state(self._api, entity_id)
def set(self, entity_id, new_state, attributes=None, force_update=False):
"""Call set_state on remote API."""
set_state(self._api, entity_id, new_state, attributes, force_update)
def mirror(self):
"""Discard current data and mirrors the remote state machine."""
self._states = {state.entity_id: state for state
in get_states(self._api)}
def _state_changed_listener(self, event):
"""Listen for state changed events and applies them."""
if event.data['new_state'] is None:
self._states.pop(event.data['entity_id'], None)
else:
self._states[event.data['entity_id']] = event.data['new_state']
class JSONEncoder(json.JSONEncoder):
"""JSONEncoder that supports Home Assistant objects."""
# pylint: disable=too-few-public-methods,method-hidden
def default(self, obj):
"""Convert Home Assistant objects.
Hand other objects to the original method.
"""
if isinstance(obj, datetime):
return obj.isoformat()
elif hasattr(obj, 'as_dict'):
return obj.as_dict()
try:
return json.JSONEncoder.default(self, obj)
except TypeError:
# If the JSON serializer couldn't serialize it
# it might be a generator, convert it to a list
try:
return [self.default(child_obj)
for child_obj in obj]
except TypeError:
# Ok, we're lost, cause the original error
return json.JSONEncoder.default(self, obj)
def validate_api(api):
"""Make a call to validate API."""
try:
req = api(METHOD_GET, URL_API)
if req.status_code == 200:
return APIStatus.OK
elif req.status_code == 401:
return APIStatus.INVALID_PASSWORD
else:
return APIStatus.UNKNOWN
except HomeAssistantError:
return APIStatus.CANNOT_CONNECT
def connect_remote_events(from_api, to_api):
"""Setup from_api to forward all events to to_api."""
data = {
'host': to_api.host,
'api_password': to_api.api_password,
'port': to_api.port
}
try:
req = from_api(METHOD_POST, URL_API_EVENT_FORWARD, data)
if req.status_code == 200:
return True
else:
_LOGGER.error(
"Error setting up event forwarding: %s - %s",
req.status_code, req.text)
return False
except HomeAssistantError:
_LOGGER.exception("Error setting up event forwarding")
return False
def disconnect_remote_events(from_api, to_api):
"""Disconnect forwarding events from from_api to to_api."""
data = {
'host': to_api.host,
'port': to_api.port
}
try:
req = from_api(METHOD_DELETE, URL_API_EVENT_FORWARD, data)
if req.status_code == 200:
return True
else:
_LOGGER.error(
"Error removing event forwarding: %s - %s",
req.status_code, req.text)
return False
except HomeAssistantError:
_LOGGER.exception("Error removing an event forwarder")
return False
def get_event_listeners(api):
"""List of events that is being listened for."""
try:
req = api(METHOD_GET, URL_API_EVENTS)
return req.json() if req.status_code == 200 else {}
except (HomeAssistantError, ValueError):
# ValueError if req.json() can't parse the json
_LOGGER.exception("Unexpected result retrieving event listeners")
return {}
def fire_event(api, event_type, data=None):
"""Fire an event at remote API."""
try:
req = api(METHOD_POST, URL_API_EVENTS_EVENT.format(event_type), data)
if req.status_code != 200:
_LOGGER.error("Error firing event: %d - %s",
req.status_code, req.text)
except HomeAssistantError:
_LOGGER.exception("Error firing event")
def get_state(api, entity_id):
"""Query given API for state of entity_id."""
try:
req = api(METHOD_GET, URL_API_STATES_ENTITY.format(entity_id))
# req.status_code == 422 if entity does not exist
return ha.State.from_dict(req.json()) \
if req.status_code == 200 else None
except (HomeAssistantError, ValueError):
# ValueError if req.json() can't parse the json
_LOGGER.exception("Error fetching state")
return None
def get_states(api):
"""Query given API for all states."""
try:
req = api(METHOD_GET,
URL_API_STATES)
return [ha.State.from_dict(item) for
item in req.json()]
except (HomeAssistantError, ValueError, AttributeError):
# ValueError if req.json() can't parse the json
_LOGGER.exception("Error fetching states")
return []
def remove_state(api, entity_id):
"""Call API to remove state for entity_id.
Return True if entity is gone (removed/never existed).
"""
try:
req = api(METHOD_DELETE, URL_API_STATES_ENTITY.format(entity_id))
if req.status_code in (200, 404):
return True
_LOGGER.error("Error removing state: %d - %s",
req.status_code, req.text)
return False
except HomeAssistantError:
_LOGGER.exception("Error removing state")
return False
def set_state(api, entity_id, new_state, attributes=None, force_update=False):
"""Tell API to update state for entity_id.
Return True if success.
"""
attributes = attributes or {}
data = {'state': new_state,
'attributes': attributes,
'force_update': force_update}
try:
req = api(METHOD_POST,
URL_API_STATES_ENTITY.format(entity_id),
data)
if req.status_code not in (200, 201):
_LOGGER.error("Error changing state: %d - %s",
req.status_code, req.text)
return False
else:
return True
except HomeAssistantError:
_LOGGER.exception("Error setting state")
return False
def is_state(api, entity_id, state):
"""Query API to see if entity_id is specified state."""
cur_state = get_state(api, entity_id)
return cur_state and cur_state.state == state
def get_services(api):
"""Return a list of dicts.
Each dict has a string "domain" and a list of strings "services".
"""
try:
req = api(METHOD_GET, URL_API_SERVICES)
return req.json() if req.status_code == 200 else {}
except (HomeAssistantError, ValueError):
# ValueError if req.json() can't parse the json
_LOGGER.exception("Got unexpected services result")
return {}
def call_service(api, domain, service, service_data=None, timeout=5):
"""Call a service at the remote API."""
try:
req = api(METHOD_POST,
URL_API_SERVICES_SERVICE.format(domain, service),
service_data, timeout=timeout)
if req.status_code != 200:
_LOGGER.error("Error calling service: %d - %s",
req.status_code, req.text)
except HomeAssistantError:
_LOGGER.exception("Error calling service")
def get_config(api):
"""Return configuration."""
try:
req = api(METHOD_GET, URL_API_CONFIG)
return req.json() if req.status_code == 200 else {}
except (HomeAssistantError, ValueError):
# ValueError if req.json() can't parse the JSON
_LOGGER.exception("Got unexpected configuration results")
return {}