def _get_printer_uri()

in export/securedrop_export/print/service.py [0:0]

• 19 lines of code
• 7 McCabe index (conditional complexity)

    def _get_printer_uri(self) -> str:
        """
        Get the URI via lpinfo. Only accept URIs of supported printers.

        Raise ExportException if supported setup is not found.
        """
        printer_uri = ""
        try:
            output = subprocess.check_output(["sudo", "lpinfo", "-v"])
        except subprocess.CalledProcessError:
            logger.error("Error attempting to retrieve printer uri with lpinfo")
            raise ExportException(sdstatus=Status.ERROR_PRINTER_URI)

        # fetch the usb printer uri
        for line in output.split():
            if "usb://" in line.decode("utf-8"):
                printer_uri = line.decode("utf-8")
                logger.info(f"lpinfo usb printer: {printer_uri}")

        # verify that the printer is supported, else throw
        if printer_uri == "":
            # No usb printer is connected
            logger.info("No usb printers connected")
            raise ExportException(sdstatus=Status.ERROR_PRINTER_NOT_FOUND)
        elif not any(x in printer_uri for x in self.SUPPORTED_PRINTERS):
            # printer url is a make that is unsupported
            logger.info(f"Printer {printer_uri} is unsupported")
            raise ExportException(sdstatus=Status.ERROR_PRINTER_NOT_SUPPORTED)

        logger.info(f"Printer {printer_uri} is supported")
        return printer_uri