HTTP backend dependencies moved from optional to required

If Platypush is supposed to work also without a manually created
`config.yaml`, and the HTTP backend is enabled by default in that
configuration, then Flask and companions should be among the required
dependencies.

platypush/backend/http/__init__.py

@@ -91,14 +91,16 @@ class HttpBackend(Backend):
                                  other music plugin enabled. -->
                             <Music class="col-3" />
 
-                            <!-- Show current date, time and weather. It requires a `weather` plugin or backend enabled -->
+                            <!-- 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. -->
+                                 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
@@ -151,11 +153,7 @@ class HttpBackend(Backend):
 
     Requires:
 
-        * **flask** (``pip install flask``)
+        * **gunicorn** (``pip install gunicorn``) - optional, to run the Platypush webapp over uWSGI.
-        * **bcrypt** (``pip install bcrypt``)
-        * **magic** (``pip install python-magic``), optional, for MIME type
-            support if you want to enable media streaming
-        * **gunicorn** (``pip install gunicorn``) - 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
@@ -174,12 +172,22 @@ class HttpBackend(Backend):
     _DEFAULT_HTTP_PORT = 8008
     _DEFAULT_WEBSOCKET_PORT = 8009
 
-    def __init__(self, port=_DEFAULT_HTTP_PORT,
+    def __init__(
+        self,
+        port=_DEFAULT_HTTP_PORT,
         websocket_port=_DEFAULT_WEBSOCKET_PORT,
         bind_address='0.0.0.0',
-                 disable_websocket=False, resource_dirs=None,
+        disable_websocket=False,
-                 ssl_cert=None, ssl_key=None, ssl_cafile=None, ssl_capath=None,
+        resource_dirs=None,
-                 maps=None, run_externally=False, uwsgi_args=None, **kwargs):
+        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
@@ -246,26 +254,37 @@ class HttpBackend(Backend):
         self.bind_address = bind_address
 
         if resource_dirs:
-            self.resource_dirs = {name: os.path.abspath(
+            self.resource_dirs = {
-                os.path.expanduser(d)) for name, d in resource_dirs.items()}
+                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,
+        self.ssl_context = (
+            get_ssl_server_context(
+                ssl_cert=ssl_cert,
                 ssl_key=ssl_key,
                 ssl_cafile=ssl_cafile,
-                                                  ssl_capath=ssl_capath) \
+                ssl_capath=ssl_capath,
-            if ssl_cert else None
+            )
+            if ssl_cert
+            else None
+        )
 
         if self.uwsgi_args:
-            self.uwsgi_args = [str(_) for _ in self.uwsgi_args] + \
+            self.uwsgi_args = [str(_) for _ in self.uwsgi_args] + [
-                ['--module', 'platypush.backend.http.uwsgi', '--enable-threads']
+                '--module',
+                'platypush.backend.http.uwsgi',
+                '--enable-threads',
+            ]
 
-        self.local_base_url = '{proto}://localhost:{port}'.\
+        self.local_base_url = '{proto}://localhost:{port}'.format(
-            format(proto=('https' if ssl_cert else 'http'), port=self.port)
+            proto=('https' if ssl_cert else 'http'), port=self.port
+        )
 
         self._websocket_lock_timeout = 10
         self._websocket_lock = threading.RLock()
@@ -284,7 +303,9 @@ class HttpBackend(Backend):
                 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')
+                    self.logger.info(
+                        'HTTP server process may be still alive at termination'
+                    )
                 else:
                     self.logger.info('HTTP server process terminated')
             else:
@@ -293,17 +314,25 @@ class HttpBackend(Backend):
                 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')
+                    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:
+        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)
+            acquire_ok = self._websocket_lock.acquire(
+                timeout=self._websocket_lock_timeout
+            )
             if not acquire_ok:
                 raise TimeoutError('Websocket lock acquire timeout')
 
@@ -313,13 +342,19 @@ class HttpBackend(Backend):
         finally:
             self._websocket_lock.release()
 
-        acquire_ok = self._websocket_locks[addr].acquire(timeout=self._websocket_lock_timeout)
+        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))
+            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)
+            acquire_ok = self._websocket_lock.acquire(
+                timeout=self._websocket_lock_timeout
+            )
             if not acquire_ok:
                 raise TimeoutError('Websocket lock acquire timeout')
 
@@ -327,12 +362,15 @@ class HttpBackend(Backend):
             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)))
+            self.logger.warning(
+                'Unhandled exception while releasing websocket lock: {}'.format(str(e))
+            )
         finally:
             self._websocket_lock.release()
 
     def notify_web_clients(self, event):
         """Notify all the connected web clients (over websocket) of a new event"""
+
         async def send_event(ws):
             try:
                 self._acquire_websocket_lock(ws)
@@ -349,7 +387,9 @@ class HttpBackend(Backend):
             try:
                 loop.run_until_complete(send_event(_ws))
             except ConnectionClosed:
-                self.logger.warning('Websocket client {} connection lost'.format(_ws.remote_address))
+                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]
@@ -359,16 +399,23 @@ class HttpBackend(Backend):
         set_thread_name('WebsocketServer')
 
         async def register_websocket(websocket, path):
-            address = websocket.remote_address if websocket.remote_address \
+            address = (
+                websocket.remote_address
+                if websocket.remote_address
                 else '<unknown client>'
+            )
 
-            self.logger.info('New websocket connection from {} on path {}'.format(address, path))
+            self.logger.info(
+                'New websocket connection from {} on path {}'.format(address, path)
+            )
             self.active_websockets.add(websocket)
 
             try:
                 await websocket.recv()
             except ConnectionClosed:
-                self.logger.info('Websocket client {} closed connection'.format(address))
+                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]
@@ -379,8 +426,13 @@ class HttpBackend(Backend):
 
         self._websocket_loop = get_or_create_event_loop()
         self._websocket_loop.run_until_complete(
-            websocket_serve(register_websocket, self.bind_address, self.websocket_port,
+            websocket_serve(
-                             **websocket_args))
+                register_websocket,
+                self.bind_address,
+                self.websocket_port,
+                **websocket_args
+            )
+        )
         self._websocket_loop.run_forever()
 
     def _start_web_server(self):
@@ -415,8 +467,9 @@ class HttpBackend(Backend):
             self.websocket_thread.start()
 
         if not self.run_externally:
-            self.server_proc = Process(target=self._start_web_server(),
+            self.server_proc = Process(
-                                       name='WebServer')
+                target=self._start_web_server(), name='WebServer'
+            )
             self.server_proc.start()
             self.server_proc.join()
         elif self.uwsgi_args:
@@ -424,9 +477,11 @@ class HttpBackend(Backend):
             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 ' +
+            self.logger.info(
-                             'no uwsgi_args were provided. Make sure that you run another external service' +
+                'The web server is configured to be launched externally but '
-                             'for the webserver (e.g. nginx)')
+                + 'no uwsgi_args were provided. Make sure that you run another external service'
+                + 'for the webserver (e.g. nginx)'
+            )
 
 
 # vim:sw=4:ts=4:et:

platypush/backend/http/manifest.yaml

@@ -2,9 +2,6 @@ manifest:
   events: {}
   install:
     pip:
-    - flask
-    - bcrypt
-    - python-magic
     - gunicorn
   package: platypush.backend.http
   type: backend

requirements.txt

@@ -20,3 +20,4 @@ zeroconf
 paho-mqtt
 websocket-client
 croniter
+python-magic

setup.py

@@ -17,7 +17,7 @@ def readfile(fname):
 def pkg_files(dir):
     paths = []
     # noinspection PyShadowingNames
-    for (path, dirs, files) in os.walk(dir):
+    for (path, _, files) in os.walk(dir):
         for file in files:
             paths.append(os.path.join('..', path, file))
     return paths
@@ -68,17 +68,21 @@ setup(
         'pyjwt',
         'marshmallow',
         'frozendict',
+        'flask',
+        'bcrypt',
+        'python-magic',
     ],
-
     extras_require={
         # Support for thread custom name
         'threadname': ['python-prctl'],
         # Support for Kafka backend and plugin
         'kafka': ['kafka-python'],
         # Support for Pushbullet backend and plugin
-        'pushbullet': ['pushbullet.py @ https://github.com/rbrcsk/pushbullet.py/tarball/master'],
+        'pushbullet': [
-        # Support for HTTP backend
+            'pushbullet.py @ https://github.com/rbrcsk/pushbullet.py/tarball/master'
-        'http': ['flask', 'bcrypt', 'python-magic', 'gunicorn'],
+        ],
+        # Support for HTTP backend over uWSGI
+        'http': ['gunicorn'],
         # Support for MQTT backends
         'mqtt': ['paho-mqtt'],
         # Support for RSS feeds parser
@@ -90,7 +94,11 @@ setup(
         # Support for MPD/Mopidy music server plugin and backend
         'mpd': ['python-mpd2'],
         # Support for Google text2speech plugin
-        'google-tts': ['oauth2client', 'google-api-python-client', 'google-cloud-texttospeech'],
+        'google-tts': [
+            'oauth2client',
+            'google-api-python-client',
+            'google-cloud-texttospeech',
+        ],
         # Support for OMXPlayer plugin
         'omxplayer': ['omxplayer-wrapper'],
         # Support for YouTube
@@ -138,7 +146,8 @@ setup(
         # Support for web media subtitles
         'subtitles': [
             'webvtt-py',
-            'python-opensubtitles @ https://github.com/agonzalezro/python-opensubtitles/tarball/master'],
+            'python-opensubtitles @ https://github.com/agonzalezro/python-opensubtitles/tarball/master',
+        ],
         # Support for mpv player plugin
         'mpv': ['python-mpv'],
         # Support for NFC tags
@@ -156,14 +165,21 @@ setup(
         # Support for Dropbox integration
         'dropbox': ['dropbox'],
         # Support for Leap Motion backend
-        'leap': ['leap-sdk @ https://github.com/BlackLight/leap-sdk-python3/tarball/master'],
+        'leap': [
+            'leap-sdk @ https://github.com/BlackLight/leap-sdk-python3/tarball/master'
+        ],
         # Support for Flic buttons
-        'flic': ['flic @ https://github.com/50ButtonsEach/fliclib-linux-hci/tarball/master'],
+        'flic': [
+            'flic @ https://github.com/50ButtonsEach/fliclib-linux-hci/tarball/master'
+        ],
         # Support for Alexa/Echo plugin
         'alexa': ['avs @ https://github.com/BlackLight/avs/tarball/master'],
         # Support for bluetooth devices
-        'bluetooth': ['pybluez', 'gattlib',
+        'bluetooth': [
-                      'pyobex @ https://github.com/BlackLight/PyOBEX/tarball/master'],
+            'pybluez',
+            'gattlib',
+            'pyobex @ https://github.com/BlackLight/PyOBEX/tarball/master',
+        ],
         # Support for TP-Link devices
         'tplink': ['pyHS100'],
         # Support for PMW3901 2-Dimensional Optical Flow Sensor
@@ -231,7 +247,9 @@ setup(
         # Support for Twilio integration
         'twilio': ['twilio'],
         # Support for DHT11/DHT22/AM2302 temperature/humidity sensors
-        'dht': ['Adafruit_Python_DHT @ git+https://github.com/adafruit/Adafruit_Python_DHT'],
+        'dht': [
+            'Adafruit_Python_DHT @ git+https://github.com/adafruit/Adafruit_Python_DHT'
+        ],
         # Support for LCD display integration
         'lcd': ['RPi.GPIO', 'RPLCD'],
         # Support for IMAP mail integration