utils: rename cache_probe() to get_cache_dev_path()

This method reports the /dev path to cache partition, rename it.

Add explicit check if blkid is successful.

And add logging to report that device path to cache is not found.

src/live/ogOperations.py

@@ -27,7 +27,7 @@ from src.utils.legacy import *
 from src.utils.net import ethtool
 from src.utils.menu import generate_menu
 from src.utils.fs import *
-from src.utils.probe import os_probe, cache_probe
+from src.utils.probe import os_probe, get_cache_dev_path
 from src.utils.disk import *
 from src.utils.cache import generate_cache_txt, umount_cache, init_cache
 from src.utils.tiptorrent import *
@@ -542,7 +542,7 @@ class OgLiveOperations:
     def refresh(self, ogRest):
         self._restartBrowser(self._url_log)
 
-        cache = cache_probe()
+        cache = get_cache_dev_path()
         disks = get_disks()
         interface = os.getenv('DEVICE')
         link = ethtool(interface)

src/utils/cache.py

@@ -11,7 +11,7 @@ import os
 
 from src.utils.fs import mount_mkdir, umount
 from src.utils.net import getifaddr
-from src.utils.probe import cache_probe
+from src.utils.probe import get_cache_dev_path
 
 OGIMG='/opt/opengnsys/images/'
 OGCACHE_MOUNTPOINT='/opt/opengnsys/cache'
@@ -23,7 +23,7 @@ def mount_cache():
 
     Returns the mountpoint or an empty string.
     """
-    cache_dev = cache_probe()
+    cache_dev = get_cache_dev_path()
 
     if cache_dev:
         # cache_target = cache_dev.replace('dev', 'mnt')

src/utils/probe.py

@@ -135,14 +135,17 @@ def get_linux_distro_id(mountpoint):
         logging.error(f'os-release file not found at "{osrelease}"')
     return 'linux'
 
-def cache_probe():
+def get_cache_dev_path():
     """
-    Runs 'blkid -L CACHE' and returns stripped stdout
+    Runs 'blkid -L CACHE' and returns stripped path to device, eg. /dev/sda3
     """
     proc_blkid = subprocess.run(['blkid', '-L', 'CACHE'],
                                 stdout=subprocess.PIPE)
-    stdout = proc_blkid.stdout.decode().strip()
-    return stdout
+    if proc_blkid.returncode != 0:
+        logging.error('Cannot find device path to cache')
+        return ''
+
+    return proc_blkid.stdout.decode().strip()
 
 
 def get_os_family(mountpoint):