kytos-ng / topology

        self.notify_metadata_changes(interface, 'added')

        return jsonify("Operation successful"), 201

    @rest('v3/interfaces/<interface_id>/metadata/<key>', methods=['DELETE'])

    def delete_interface_metadata(self, interface_id, key):

        """Delete metadata from an interface."""

        switch_id = ":".join(interface_id.split(":")[:-1])

        interface_number = int(interface_id.split(":")[-1])

        try:

            switch = self.controller.switches[switch_id]

        except KeyError:

            return jsonify("Switch not found"), 404

        try:

            interface = switch.interfaces[interface_number]

        except KeyError:

            return jsonify("Interface not found"), 404

        if interface.remove_metadata(key) is False:

            return jsonify("Metadata not found"), 404

        self.notify_metadata_changes(interface, 'removed')

        return jsonify("Operation successful"), 200

    # Link related methods

    @rest('v3/links')

        return jsonify({"metadata": interface.metadata}), 200

    @rest('v3/interfaces/<interface_id>/metadata', methods=['POST'])

    def add_interface_metadata(self, interface_id):

        """Add metadata to an interface."""

        metadata = self._get_metadata()

        switch_id = ":".join(interface_id.split(":")[:-1])

        interface_number = int(interface_id.split(":")[-1])

        try:

            switch = self.controller.switches[switch_id]

        except KeyError:

            return jsonify("Switch not found"), 404

        try:

            interface = switch.interfaces[interface_number]

        except KeyError:

            return jsonify("Interface not found"), 404

        interface.extend_metadata(metadata)

        self.notify_metadata_changes(interface, 'added')

        return jsonify("Operation successful"), 201

    @rest('v3/interfaces/<interface_id>/metadata/<key>', methods=['DELETE'])

    def delete_interface_metadata(self, interface_id, key):