legacy: improve readability of cambiar_accesso

Expand function docstring and do not use CalledProcessError handling to
return True or False. Just checking for returncode value is simpler.

src/utils/legacy.py

@@ -5,7 +5,7 @@ import subprocess
 import shlex
 import shutil
 
-from subprocess import PIPE
+from subprocess import PIPE, DEVNULL
 
 def ogGetImageInfo(path):
     """
@@ -29,20 +29,20 @@ def ogGetImageInfo(path):
 
 def cambiar_acceso(mode='rw', user='opengnsys', pwd='og'):
     """
-    'CambiarAcceso' wrapper (admin/Interface/CambiarAcceso)
+    'CambiarAcceso' (admin/Interface/CambiarAcceso) rewrite into native Python.
+
+    Remount the (remote) samba directory that contains the OpenGnsys images.
+    Specify access mode ('rw', or 'ro') with mode parameter (default 'rw').
+    Specify samba credentials with user and pwd parameter.
+
+    Return True if exit-code was 0. Return False otherwise.
     """
     if mode not in ['rw', 'ro']:
         raise ValueError('Invalid remount mode option')
 
     cmd = shlex.split(f'mount -o remount,{mode},username={user},password={pwd} /opt/opengnsys/images')
-    ret = True
-    try:
-        subprocess.run(cmd, check=True)
-    except CalledProcessError:
-        ret = False
-    finally:
-        return ret
-
+    p = subprocess.run(cmd, stdout=DEVNULL, stderr=DEVNULL)
+    return p.returncode == 0
 
 def ogChangeRepo(ip):
     """