fix bug where nfs/network mounts could not be specified (LP: #603329)

What caused this was having an open ended list on what "names" might be
found in the metadata service.  That list is now trimmed down to the
the following values:
 ephemeral*
 root
 ami
 swap

The above list was found from crawled medata data services in the latest
maverick tests I did.  The following is the complete list of entries that
were there:
 'ami': '/dev/sda1',
 'ami': 'sda1',
 'ephemeral0': '/dev/sda2'
 'ephemeral0': '/dev/sdb'
 'ephemeral0': 'sda2'
 'ephemeral0': 'sdb'
 'ephemeral1': 'sdc'
 'ephemeral2': 'sdd'
 'ephemeral3': 'sde'
 'root': '/dev/sda1'
 'root': '/dev/sda1'
 'swap': 'sda3'

Also, this limits which devices will have "/dev/" prepended to them to
sda, sda1, xvda, xvda1, hda1, hda, vda.

LP: #603329

1 files changed, 23 insertions, 19 deletions

diff --git a/cloudinit/CloudConfig/cc_mounts.py b/cloudinit/CloudConfig/cc_mounts.py
index ffc647aa..d48177d0 100644
--- a/cloudinit/CloudConfig/cc_mounts.py
+++ b/cloudinit/CloudConfig/cc_mounts.py
@@ -20,6 +20,14 @@ import os
 import re
 import string
 
+def is_mdname(name):
+    # return true if this is a metadata service name
+    if name in [ "ami", "root", "swap" ]:
+        return True
+    if name.startswith("ephemeral") and name.find(":") == -1:
+        return True
+    return False
+
 def handle(name,cfg,cloud,log,args):
     # these are our default set of mounts
     defmnts = [ [ "ephemeral0", "/mnt", "auto", "defaults", "0", "0" ],
@@ -32,6 +40,10 @@ def handle(name,cfg,cloud,log,args):
     if cfg.has_key("mounts"):
         cfgmnt = cfg["mounts"]
 
+    # shortname matches 'sda', 'sda1', 'xvda', 'hda'
+    shortname_filter = r"^[x]{0,1}[shv]d[a-z][0-9]*$"
+    shortname = re.compile(shortname_filter)
+
     for i in range(len(cfgmnt)):
         # skip something that wasn't a list
         if not isinstance(cfgmnt[i],list): continue
@@ -41,24 +53,19 @@ def handle(name,cfg,cloud,log,args):
         if cfgmnt[i][0] == "ephemeral":
             cfgmnt[i][0] = "ephemeral0"
 
-        newname = cfgmnt[i][0]
-        if not newname.startswith("/"):
+        if is_mdname(cfgmnt[i][0]):
             newname = cloud.device_name_to_device(cfgmnt[i][0])
-        if newname is not None:
-            cfgmnt[i][0] = newname
-        else:
-            # there is no good way of differenciating between
-            # a name that *couldn't* exist in the md service and
-            # one that merely didnt
-            # in order to allow user to specify 'sda3' rather
-            # than '/dev/sda3', go through some hoops
-            ok = False
-            for f in [ "/", "sd", "hd", "vd", "xvd" ]:
-                if cfgmnt[i][0].startswith(f):
-                    ok = True
-                    break
-            if not ok:
+            if not newname:
+                log.debug("ignoring nonexistant named mount %s" % cfgmnt[i][0])
                 cfgmnt[i][1] = None
+            else:
+                if newname.startswith("/"):
+                    cfgmnt[i][0] = newname
+                else:
+                    cfgmnt[i][0] = "/dev/%s" % newname
+        else:
+            if shortname.match(cfgmnt[i][0]):
+                cfgmnt[i][0] = "/dev/%s" % cfgmnt[i][0]
 
     for i in range(len(cfgmnt)):
         # fill in values with 
@@ -68,9 +75,6 @@ def handle(name,cfg,cloud,log,args):
             elif cfgmnt[i][j] is None:
                 cfgmnt[i][j] = defvals[j]
 
-        if not cfgmnt[i][0].startswith("/"):
-            cfgmnt[i][0]="/dev/%s" % cfgmnt[i][0]
-
         # if the second entry in the list is 'None' this
         # clears all previous entries of that same 'fs_spec'
         # (fs_spec is the first field in /etc/fstab, ie, that device)