Fix growpart for some cases when booted with root=PARTUUID.

Growing the root partition would fail in either of two cases:
 a.) if the device /dev/root existed
 b.) the kernel command line had upper case letters in PARTUUID=<value>
     the kernel will accept upper case partuuid, but udev creates
     links with lower case. In that scenario, we need to adjust to
     a /dev/disk/by-<partuuid|uuid> with lower case.

The fix here addresses that, and also fixes uuid similarly for the
lowercase issue.

LP: #1684869

1 files changed, 5 insertions, 1 deletions

diff --git a/cloudinit/config/cc_growpart.py b/cloudinit/config/cc_growpart.py
index 089693e8..d2bc6e6c 100644
--- a/cloudinit/config/cc_growpart.py
+++ b/cloudinit/config/cc_growpart.py
@@ -252,9 +252,13 @@ def devent2dev(devent):
     container = util.is_container()
 
     # Ensure the path is a block device.
-    if (dev == "/dev/root" and not os.path.exists(dev) and not container):
+    if (dev == "/dev/root" and not container):
         dev = util.rootdev_from_cmdline(util.get_cmdline())
         if dev is None:
+            if os.path.exists(dev):
+                # if /dev/root exists, but we failed to convert
+                # that to a "real" /dev/ path device, then return it.
+                return dev
             raise ValueError("Unable to find device '/dev/root'")
     return dev