Source code for platypush.backend.http

import os
import subprocess
import threading

from multiprocessing import Process

from platypush.backend import Backend
from platypush.backend.http.app import application
from platypush.context import get_or_create_event_loop
from platypush.utils import get_ssl_server_context, set_thread_name


[docs]class HttpBackend(Backend): """ The HTTP backend is a general-purpose web server. Example configuration: .. code-block:: yaml backend.http: # Default HTTP listen port port: 8008 # Default websocket port websocket_port: 8009 # External folders that will be exposed over `/resources/<name>` resource_dirs: photos: /mnt/hd/photos videos: /mnt/hd/videos music: /mnt/hd/music You can leverage this backend: * To execute Platypush commands via HTTP calls. In order to do so: * Register a user to Platypush through the web panel (usually served on ``http://host:8008/``). * Generate a token for your user, either through the web panel (Settings -> Generate Token) or via API: .. code-block:: shell curl -XPOST -H 'Content-Type: application/json' -d ' { "username": "$YOUR_USER", "password": "$YOUR_PASSWORD" }' http://host:8008/auth * Execute actions through the ``/execute`` endpoint: .. code-block:: shell curl -XPOST -H 'Content-Type: application/json' -H "Authorization: Bearer $YOUR_TOKEN" -d ' { "type": "request", "action": "tts.say", "args": { "text": "This is a test" } }' http://host:8008/execute * To interact with your system (and control plugins and backends) through the Platypush web panel, by default available on ``http://host:8008/``. Any configured plugin that has an available panel plugin will be automatically added to the web panel. * To display a fullscreen dashboard with custom widgets. * Widgets are available as Vue.js components under ``platypush/backend/http/webapp/src/components/widgets``. * Explore their options (some may require some plugins or backends to be configured in order to work) and create a new dashboard template under ``~/.config/platypush/dashboards``- e.g. ``main.xml``: .. code-block:: xml <Dashboard> <!-- Display the following widgets on the same row. Each row consists of 12 columns. You can specify the width of each widget either through class name (e.g. col-6 means 6 columns out of 12, e.g. half the size of the row) or inline style (e.g. `style="width: 50%"`). --> <Row> <!-- Show a calendar widget with the upcoming events. It requires the `calendar` plugin to be enabled and configured. --> <Calendar class="col-6" /> <!-- Show the current track and other playback info. It requires `music.mpd` plugin or any other music plugin enabled. --> <Music class="col-3" /> <!-- Show current date, time and weather. It requires a `weather` plugin or backend enabled --> <DateTimeWeather class="col-3" /> </Row> <!-- Display the following widgets on a second row --> <Row> <!-- Show a carousel of images from a local folder. For security reasons, the folder must be explicitly exposed as an HTTP resource through the backend `resource_dirs` attribute. --> <ImageCarousel class="col-6" img-dir="/mnt/hd/photos/carousel" /> <!-- Show the news headlines parsed from a list of RSS feed and stored locally through the `http.poll` backend --> <RssNews class="col-6" db="sqlite:////path/to/your/rss.db" /> </Row> </Dashboard> * The dashboard will be accessible under ``http://host:8008/dashboard/<name>``, where ``name=main`` if for example you stored your template under ``~/.config/platypush/dashboards/main.xml``. * To expose custom endpoints that can be called as web hooks by other applications and run some custom logic. All you have to do in this case is to create a hook on a :class:`platypush.message.event.http.hook.WebhookEvent` with the endpoint that you want to expose and store it under e.g. ``~/.config/platypush/scripts/hooks.py``: .. code-block:: python from platypush.context import get_plugin from platypush.event.hook import hook from platypush.message.event.http.hook import WebhookEvent hook_token = 'abcdefabcdef' # Expose the hook under the /hook/lights_toggle endpoint @hook(WebhookEvent, hook='lights_toggle') def lights_toggle(event, **context): # Do any checks on the request assert event.headers.get('X-Token') == hook_token, 'Unauthorized' # Run some actions lights = get_plugin('light.hue') lights.toggle() Any plugin can register custom routes under ``platypush/backend/http/app/routes/plugins``. Any additional route is managed as a Flask blueprint template and the `.py` module can expose lists of routes to the main webapp through the ``__routes__`` object (a list of Flask blueprints). Security: Access to the endpoints requires at least one user to be registered. Access to the endpoints is regulated in the following ways (with the exception of event hooks, whose logic is up to the user): * **Simple authentication** - i.e. registered username and password. * **JWT token** provided either over as ``Authorization: Bearer`` header or ``GET`` ``?token=<TOKEN>`` parameter. A JWT token can be generated either through the web panel or over the ``/auth`` endpoint. * **Global platform token**, usually configured on the root of the ``config.yaml`` as ``token: <VALUE>``. It can provided either over on the ``X-Token`` header or as a ``GET`` ``?token=<TOKEN>`` parameter. * **Session token**, generated upon login, it can be used to authenticate requests through the ``Cookie`` header (cookie name: ``session_token``). Requires: * **flask** (``pip install flask``) * **redis** (``pip install redis``) * **websockets** (``pip install websockets``) * **python-dateutil** (``pip install python-dateutil``) * **magic** (``pip install python-magic``), optional, for MIME type support if you want to enable media streaming * **uwsgi** (``pip install uwsgi`` plus uwsgi server installed on your system if required) - optional but recommended. By default the Platypush web server will run in a process spawned on the fly by the HTTP backend. However, being a Flask app, it will serve clients in a single thread and won't support many features of a full-blown web server. Base command to run the web server over uwsgi:: uwsgi --http :8008 --module platypush.backend.http.uwsgi --master --processes 4 --threads 4 Bear in mind that the main webapp is defined in ``platypush.backend.http.app:application`` and the WSGI startup script is stored under ``platypush/backend/http/uwsgi.py``. """ _DEFAULT_HTTP_PORT = 8008 _DEFAULT_WEBSOCKET_PORT = 8009
[docs] def __init__(self, port=_DEFAULT_HTTP_PORT, websocket_port=_DEFAULT_WEBSOCKET_PORT, bind_address='0.0.0.0', disable_websocket=False, resource_dirs=None, ssl_cert=None, ssl_key=None, ssl_cafile=None, ssl_capath=None, maps=None, run_externally=False, uwsgi_args=None, **kwargs): """ :param port: Listen port for the web server (default: 8008) :type port: int :param websocket_port: Listen port for the websocket server (default: 8009) :type websocket_port: int :param bind_address: Address/interface to bind to (default: 0.0.0.0, accept connection from any IP) :type bind_address: str :param disable_websocket: Disable the websocket interface (default: False) :type disable_websocket: bool :param ssl_cert: Set it to the path of your certificate file if you want to enable HTTPS (default: None) :type ssl_cert: str :param ssl_key: Set it to the path of your key file if you want to enable HTTPS (default: None) :type ssl_key: str :param ssl_cafile: Set it to the path of your certificate authority file if you want to enable HTTPS (default: None) :type ssl_cafile: str :param ssl_capath: Set it to the path of your certificate authority directory if you want to enable HTTPS (default: None) :type ssl_capath: str :param resource_dirs: Static resources directories that will be accessible through ``/resources/<path>``. It is expressed as a map where the key is the relative path under ``/resources`` to expose and the value is the absolute path to expose. :type resource_dirs: dict[str, str] :param run_externally: If set, then the HTTP backend will not directly spawn the web server. Set this option if you plan to run the webapp in a separate web server (recommended), like uwsgi or uwsgi+nginx. :type run_externally: bool :param uwsgi_args: If ``run_externally`` is set and you would like the HTTP backend to directly spawn and control the uWSGI application server instance, then pass the list of uWSGI arguments through this parameter. Some examples include:: # Start uWSGI instance listening on HTTP port 8008 with 4 # processes ['--plugin', 'python', '--http-socket', ':8008', '--master', '--processes', '4'] # Start uWSGI instance listening on uWSGI socket on port 3031. # You can then use another full-blown web server, like nginx # or Apache, to communicate with the uWSGI instance ['--plugin', 'python', '--socket', '127.0.0.1:3031', '--master', '--processes', '4'] :type uwsgi_args: list[str] """ super().__init__(**kwargs) self.port = port self.websocket_port = websocket_port self.maps = maps or {} self.server_proc = None self.disable_websocket = disable_websocket self.websocket_thread = None self._websocket_loop = None self.bind_address = bind_address if resource_dirs: self.resource_dirs = {name: os.path.abspath( os.path.expanduser(d)) for name, d in resource_dirs.items()} else: self.resource_dirs = {} self.active_websockets = set() self.run_externally = run_externally self.uwsgi_args = uwsgi_args or [] self.ssl_context = get_ssl_server_context(ssl_cert=ssl_cert, ssl_key=ssl_key, ssl_cafile=ssl_cafile, ssl_capath=ssl_capath) \ if ssl_cert else None if self.uwsgi_args: self.uwsgi_args = [str(_) for _ in self.uwsgi_args] + \ ['--module', 'platypush.backend.http.uwsgi', '--enable-threads'] self.local_base_url = '{proto}://localhost:{port}'.\ format(proto=('https' if ssl_cert else 'http'), port=self.port) self._websocket_lock_timeout = 10 self._websocket_lock = threading.RLock() self._websocket_locks = {}
[docs] def send_message(self, msg, **kwargs): self.logger.warning('Use cURL or any HTTP client to query the HTTP backend')
[docs] def on_stop(self): """ On backend stop """ super().on_stop() self.logger.info('Received STOP event on HttpBackend') if self.server_proc: if isinstance(self.server_proc, subprocess.Popen): self.server_proc.kill() self.server_proc.wait(timeout=10) if self.server_proc.poll() is not None: self.logger.info('HTTP server process may be still alive at termination') else: self.logger.info('HTTP server process terminated') else: self.server_proc.terminate() self.server_proc.join(timeout=10) if self.server_proc.is_alive(): self.server_proc.kill() if self.server_proc.is_alive(): self.logger.info('HTTP server process may be still alive at termination') else: self.logger.info('HTTP server process terminated') if self.websocket_thread and self.websocket_thread.is_alive() and self._websocket_loop: self._websocket_loop.stop() self.logger.info('HTTP websocket service terminated')
def _acquire_websocket_lock(self, ws): try: acquire_ok = self._websocket_lock.acquire(timeout=self._websocket_lock_timeout) if not acquire_ok: raise TimeoutError('Websocket lock acquire timeout') addr = ws.remote_address if addr not in self._websocket_locks: self._websocket_locks[addr] = threading.RLock() finally: self._websocket_lock.release() acquire_ok = self._websocket_locks[addr].acquire(timeout=self._websocket_lock_timeout) if not acquire_ok: raise TimeoutError('Websocket on address {} not ready to receive data'.format(addr)) def _release_websocket_lock(self, ws): try: acquire_ok = self._websocket_lock.acquire(timeout=self._websocket_lock_timeout) if not acquire_ok: raise TimeoutError('Websocket lock acquire timeout') addr = ws.remote_address if addr in self._websocket_locks: self._websocket_locks[addr].release() except Exception as e: self.logger.warning('Unhandled exception while releasing websocket lock: {}'.format(str(e))) finally: self._websocket_lock.release()
[docs] def notify_web_clients(self, event): """ Notify all the connected web clients (over websocket) of a new event """ import websockets async def send_event(ws): try: self._acquire_websocket_lock(ws) await ws.send(str(event)) except Exception as e: self.logger.warning('Error on websocket send_event: {}'.format(e)) finally: self._release_websocket_lock(ws) loop = get_or_create_event_loop() wss = self.active_websockets.copy() for _ws in wss: try: loop.run_until_complete(send_event(_ws)) except websockets.exceptions.ConnectionClosed: self.logger.warning('Websocket client {} connection lost'.format(_ws.remote_address)) self.active_websockets.remove(_ws) if _ws.remote_address in self._websocket_locks: del self._websocket_locks[_ws.remote_address]
[docs] def websocket(self): """ Websocket main server """ import websockets set_thread_name('WebsocketServer') async def register_websocket(websocket, path): address = websocket.remote_address if websocket.remote_address \ else '<unknown client>' self.logger.info('New websocket connection from {} on path {}'.format(address, path)) self.active_websockets.add(websocket) try: await websocket.recv() except websockets.exceptions.ConnectionClosed: self.logger.info('Websocket client {} closed connection'.format(address)) self.active_websockets.remove(websocket) if address in self._websocket_locks: del self._websocket_locks[address] websocket_args = {} if self.ssl_context: websocket_args['ssl'] = self.ssl_context self._websocket_loop = get_or_create_event_loop() self._websocket_loop.run_until_complete( websockets.serve(register_websocket, self.bind_address, self.websocket_port, **websocket_args)) self._websocket_loop.run_forever()
def _start_web_server(self): def proc(): self.logger.info('Starting local web server on port {}'.format(self.port)) kwargs = { 'host': self.bind_address, 'port': self.port, 'use_reloader': False, 'debug': False, } application.config['redis_queue'] = self.bus.redis_queue if self.ssl_context: kwargs['ssl_context'] = self.ssl_context application.run(**kwargs) return proc
[docs] def run(self): super().run() self.register_service(port=self.port) if not self.disable_websocket: self.logger.info('Initializing websocket interface') self.websocket_thread = threading.Thread(target=self.websocket) self.websocket_thread.start() if not self.run_externally: self.server_proc = Process(target=self._start_web_server(), name='WebServer') self.server_proc.start() self.server_proc.join() elif self.uwsgi_args: uwsgi_cmd = ['uwsgi'] + self.uwsgi_args self.logger.info('Starting uWSGI with arguments {}'.format(uwsgi_cmd)) self.server_proc = subprocess.Popen(uwsgi_cmd) else: self.logger.info('The web server is configured to be launched externally but ' + 'no uwsgi_args were provided. Make sure that you run another external service' + 'for the webserver (e.g. nginx)')
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