fix bug mounting first partition of a alias'd name.

The expected behavior was that 'ephemeral0' in a mount device entry
and ephemeral0 mapped to /dev/xvdb that /dev/xvdb1 or /dev/xvdb would
be substituted.

Explicitly setting 'ephemeral0.0' would mean only xvdb in this case.

ChangeLog

@@ -1,5 +1,7 @@
 0.7.4:
- -
+ - fix issue mounting 'ephemeral0' if ephemeral0 was an alias for a
+   partitioned block device with target filesystem on ephemeral0.1.
+   (LP: #1236594)
 0.7.3:
  - fix omnibus chef installer (LP: #1182265) [Chris Wing]
  - small fix for OVF datasource for iso transport on non-iso9660 filesystem

cloudinit/config/cc_mounts.py

@@ -222,9 +222,6 @@ def devnode_for_dev_part(device, partition):
     if not os.path.exists(device):
         return None
 
-    if not partition:
-        return device
-
     short_name = os.path.basename(device)
     sys_path = "/sys/block/%s" % short_name
 
@@ -238,8 +235,7 @@ def devnode_for_dev_part(device, partition):
         partition = str(partition)
 
     if partition is None:
-        valid_mappings = [sys_long_path + "1",
-                          sys_long_path + "p1" % partition]
+        valid_mappings = [sys_long_path + "1", sys_long_path + "p1"]
     elif partition != "0":
         valid_mappings = [sys_long_path + "%s" % partition,
                           sys_long_path + "p%s" % partition]