Create SysCmds common class, and refactor Python codebase (#697)

* Move the oled script's PiCmds module to common, and rename it SysCmds.

* Use sys_cmds.get_ip_and_host() in web UI code.

* Move the auth_active() method to device_utils

* Rename device_utils to web_utils. Make auth_active() method take the group as argument.

* Migrate all pi_cmds methods to the SysCmds common class.

* Display hostname and ip in Web UI.

* Resolve or suppress pylint warnings.

* Resolve a pylint warning.

* Resolve or suppress pylint warnings.

* Import libraries at the top level for readability. In my testing on a Pi3B+, this leads to ~1.5k more memory being used by the python3 process.

* Change page title as requested by akuker.

* Reenable the import-outside-toplevel pylint rule.

* Resolve pylint warnings.

* Fix error following refactoring.

* Minor UI tweaks.

* Cleanup.

* Break out bridge config validation into a utility method.

* Move the dropzonejs method into the web_utils package

* Move get_logs method into SysCmds class.

* Improve get logs UI.

* Resolve pylint warning.

* Standardize class instance name.

python/oled/src/pi_cmds.py

@@ -1,21 +0,0 @@
-"""
-Module with methods that interact with the Pi's Linux system
-"""
-
-
-def get_ip_and_host():
-    """
-    Use a mock socket connection to identify the Pi's hostname and IP address
-    """
-    from socket import socket, gethostname, AF_INET, SOCK_DGRAM
-    host = gethostname()
-    sock = socket(AF_INET, SOCK_DGRAM)
-    try:
-        # mock ip address; doesn't have to be reachable
-        sock.connect(('10.255.255.255', 1))
-        ip_addr = sock.getsockname()[0]
-    except Exception:
-        ip_addr = False
-    finally:
-        sock.close()
-    return ip_addr, host

python/oled/src/rascsi_oled_monitor.py

@@ -39,9 +39,9 @@ from board import I2C
 from adafruit_ssd1306 import SSD1306_I2C
 from PIL import Image, ImageDraw, ImageFont
 from interrupt_handler import GracefulInterruptHandler
-from pi_cmds import get_ip_and_host
 from rascsi.ractl_cmds import RaCtlCmds
 from rascsi.socket_cmds import SocketCmds
+from rascsi.sys_cmds import SysCmds
 
 parser = argparse.ArgumentParser(description="RaSCSI OLED Monitor script")
 parser.add_argument(
@@ -99,6 +99,7 @@ TOKEN = args.password
 
 sock_cmd = SocketCmds(host=args.rascsi_host, port=args.rascsi_port)
 ractl_cmd = RaCtlCmds(sock_cmd=sock_cmd, token=TOKEN)
+sys_cmd = SysCmds()
 
 WIDTH = 128
 BORDER = 5
@@ -159,7 +160,7 @@ LINE_SPACING = 8
 # Some other nice fonts to try: http://www.dafont.com/bitmap.php
 FONT = ImageFont.truetype('resources/type_writer.ttf', FONT_SIZE)
 
-IP_ADDR, HOSTNAME = get_ip_and_host()
+IP_ADDR, HOSTNAME = sys_cmd.get_ip_and_host()
 REMOVABLE_DEVICE_TYPES = ractl_cmd.get_removable_device_types()
 PERIPHERAL_DEVICE_TYPES = ractl_cmd.get_peripheral_device_types()
 
@@ -183,7 +184,7 @@ def formatted_output():
                 else:
                     output.append(f"{line['id']} {line['device_type'][2:4]} {line['status']}")
             # Special handling of devices that don't use image files
-            elif line["device_type"] in (PERIPHERAL_DEVICE_TYPES):
+            elif line["device_type"] in PERIPHERAL_DEVICE_TYPES:
                 if line["vendor"] == "RaSCSI":
                     output.append(f"{line['id']} {line['device_type'][2:4]} {line['product']}")
                 else: