Add and remove interfaces while the device is connected

Signed-off-by: Simone Orru <simone.orru@secomind.com>

astarte/device/__init__.py

@@ -41,4 +41,6 @@
     InterfaceFileDecodeError,
     InterfaceNotFoundError,
     JWTGenerationError,
+    DeviceConnectingError,
+    DeviceDisconnectedError,
 )

astarte/device/database.py

@@ -85,6 +85,17 @@ def delete_prop(self, interface: str, path: str) -> None:
             The path to the property endpoint.
         """
 
+    @abstractmethod
+    def delete_props_from_interface(self, interface: str) -> None:
+        """
+        Delete all the properties from the database belonging to an interface.
+
+        Parameters
+        ----------
+        interface : str
+            The interface name.
+        """
+
     @abstractmethod
     def clear(self) -> None:
         """
@@ -206,6 +217,22 @@ def delete_prop(self, interface: str, path: str) -> None:
         )
         connection.commit()
 
+    def delete_props_from_interface(self, interface: str) -> None:
+        """
+        Delete all the properties from the database belonging to an interface.
+
+        Parameters
+        ----------
+        interface : str
+            See documentation in AstarteDatabase.
+        """
+        connection = sqlite3.connect(self.__database_path)
+        connection.cursor().execute(
+            "DELETE FROM properties WHERE interface=?",
+            (interface,),
+        )
+        connection.commit()
+
     def clear(self) -> None:
         """
         Fully clear the database of all the properties.

astarte/device/device.py

@@ -90,9 +90,6 @@ def add_interface_from_json(self, interface_json: dict):
         """
         Adds an interface to the device.
 
-        It has to be called before :py:func:`connect`, as it will be used for building the device
-        introspection.
-
         Parameters
         ----------
         interface_json : dict
@@ -157,9 +154,6 @@ def remove_interface(self, interface_name: str) -> None:
         """
         Removes an Interface from the device.
 
-        Removes an Interface definition from the device. It has to be called before
-        :py:func:`connect`, as it will be used for building the device introspection.
-
         Parameters
         ----------
         interface_name : str

astarte/device/device_mqtt.py

@@ -34,7 +34,14 @@
 from astarte.device import crypto, pairing_handler
 from astarte.device.interface import Interface
 from astarte.device.database import AstarteDatabaseSQLite, AstarteDatabase
-from astarte.device.exceptions import ValidationError, PersistencyDirectoryNotFoundError, APIError
+from astarte.device.exceptions import (
+    ValidationError,
+    PersistencyDirectoryNotFoundError,
+    APIError,
+    InterfaceNotFoundError,
+    DeviceConnectingError,
+    DeviceDisconnectedError,
+)
 
 from astarte.device.device import Device
 
@@ -147,6 +154,7 @@ def __init__(
         # TODO: Implement device registration using token on connect
         # self.__jwt_token: str | None = None
         self.__is_crypto_setup = False
+        self.__is_connecting = False
         self.__is_connected = False
         self.__ignore_ssl_errors = ignore_ssl_errors
 
@@ -172,8 +180,18 @@ def add_interface_from_json(self, interface_json: dict):
         ----------
         interface_json : dict
             See parent class.
+
+        Raises
+        ------
+        DeviceConnectingError
+            When attempting to add an interface while the device if performing a connection.
         """
+        if self.__is_connecting:
+            raise DeviceConnectingError("Interfaces cannot be added while device is connecting.")
         self._introspection.add_interface(interface_json)
+        if self.__is_connected:
+            self.__subscribe_interface(Interface(interface_json))
+            self.__send_introspection()
 
     def remove_interface(self, interface_name: str) -> None:
         """
@@ -183,8 +201,25 @@ def remove_interface(self, interface_name: str) -> None:
         ----------
         interface_name : str
             See parent class.
-        """
+
+        Raises
+        ------
+        DeviceConnectingError
+            When attempting to add an interface while the device if performing a connection.
+        InterfaceNotFoundError
+            When the provided interface can't be found in the device introspection.
+        """
+        if self.__is_connecting:
+            raise DeviceConnectingError("Interfaces cannot be removed while device is connecting.")
+        interface = self._introspection.get_interface(interface_name)
+        if interface is None:
+            raise InterfaceNotFoundError(f"Interface {interface_name} not found in introspection.")
         self._introspection.remove_interface(interface_name)
+        if self.__is_connected:
+            if interface.is_type_properties():
+                self.__prop_database.delete_props_from_interface(interface_name)
+            self.__send_introspection()
+            self.__unsubscribe_interface(interface)
 
     def get_device_id(self) -> str:
         """
@@ -272,6 +307,7 @@ def connect(self) -> None:
         if (parsed_url.hostname is None) or (parsed_url.port is None):
             raise APIError("Received invalid broker URL.")
 
+        self.__is_connecting = True
         self.__mqtt_client.connect_async(parsed_url.hostname, parsed_url.port)
         self.__mqtt_client.loop_start()
 
@@ -326,12 +362,17 @@ def _send_generic(
 
         Raises
         ------
+        DeviceDisconnectedError
+            When this function is called while the device is not connected to Astarte.
         ValidationError
             When:
             - Attempting to send to a server owned interface.
             - Sending to an endpoint that is not present in the interface.
             - The payload validation fails.
         """
+        if not self.__is_connected:
+            raise DeviceDisconnectedError("Send operation failed due to missing connection.")
+
         bson_payload = b""
         if payload is not None:
             object_payload = {"v": payload}
@@ -388,6 +429,7 @@ def __on_connect(self, _client, _userdata, flags: dict, rc):
             return
 
         self.__is_connected = True
+        self.__is_connecting = False
 
         if not flags["session present"]:
             logging.debug("Session flag is not present, performing a clean session procedure")
@@ -517,8 +559,36 @@ def __setup_subscriptions(self) -> None:
             f"{self.__get_base_topic()}/control/consumer/properties", qos=2
         )
         for interface in self._introspection.get_all_server_owned_interfaces():
+            self.__subscribe_interface(interface)
+
+    def __subscribe_interface(self, interface: Interface) -> None:
+        """
+        Subscribe an interface to a topic from the MQTT broker.
+
+        This interface only performs the subscription for server owned interfaces.
+
+        Parameters
+        ----------
+        interface: Interface
+            The server owned interface to use for the subscription.
+        """
+        if interface.is_server_owned():
             self.__mqtt_client.subscribe(f"{self.__get_base_topic()}/{interface.name}/#", qos=2)
 
+    def __unsubscribe_interface(self, interface: Interface) -> None:
+        """
+        Unsubscribe an interface to a topic from the MQTT broker.
+
+        This interface only performs the unsubscription for server owned interfaces.
+
+        Parameters
+        ----------
+        interface: Interface
+            The server owned interface to use for the unsubscription.
+        """
+        if interface.is_server_owned():
+            self.__mqtt_client.unsubscribe(f"{self.__get_base_topic()}/{interface.name}/#")
+
     def __send_introspection(self) -> None:
         """
         Utility function used to send the introspection to Astarte

astarte/device/exceptions.py

@@ -111,3 +111,26 @@ class JWTGenerationError(AstarteError):
 
     def __init__(self, msg):
         self.msg = msg
+
+
+class DeviceConnectingError(AstarteError):
+    """Exception raised when an operation is attempted while the device MQTT client has been
+    started but is not yet connected.
+
+    Attributes:
+        msg -- A message error carrying further details
+    """
+
+    def __init__(self, msg):
+        self.msg = msg
+
+
+class DeviceDisconnectedError(AstarteError):
+    """Exception raised if attempting a send while the device is disconnected from Astarte.
+
+    Attributes:
+        msg -- A message error carrying further details
+    """
+
+    def __init__(self, msg):
+        self.msg = msg

tests/test_database.py

@@ -200,6 +200,26 @@ def test_delete_property(self, mock_sqlite3_connect):
         )
         mock_connection.commit.assert_called_once_with()
 
+    @mock.patch("astarte.device.database.sqlite3.connect")
+    def test_delete_props_from_interface(self, mock_sqlite3_connect):
+        mock_database_name = mock.MagicMock()
+
+        mock_connection = mock_sqlite3_connect.return_value
+        mock_cursor = mock_sqlite3_connect.return_value.cursor.return_value
+
+        db = database.AstarteDatabaseSQLite(mock_database_name)
+        mock_sqlite3_connect.reset_mock()
+
+        mock_interface = mock.MagicMock()
+        mock_path = mock.MagicMock()
+        db.delete_props_from_interface(mock_interface)
+
+        mock_sqlite3_connect.assert_called_once_with(mock_database_name)
+        mock_sqlite3_connect.return_value.cursor.assert_called_once_with()
+        execute_expected_arg = "DELETE FROM properties WHERE interface=?"
+        mock_cursor.execute.assert_called_once_with(execute_expected_arg, (mock_interface))
+        mock_connection.commit.assert_called_once_with()
+
     @mock.patch("astarte.device.database.sqlite3.connect")
     def test_clear(self, mock_sqlite3_connect):
         mock_database_name = mock.MagicMock()