Mountpoint containing a space not working

[Anisse Astier]

If I want to mount a directory containing a space (for example to match a remote share name), it will not work currently with the default cc_mounts plugin.

 - if I surround the mountpoint with quotes, it will create the destination directory properly, but then /etc/fstab won't contain the quotes and the spaces will cause parsing error in /etc/fstab
 - If I use the common workaround of replacing spaces with \040, then the directory will contain a literal '\' and then '040', and the mountpoint won't be found because mount interprets the escape sequence properly.

My suggestion: when outputting to /etc/fstab, escape spaces (and any other character part of fstab grammar) properly. This way the cloud-init config will just work.

[Dan Watkins (oddbloke)]

Hi Anisse,

Thanks for using cloud-init and filing this bug! To be sure that we can reproduce the exact issue you're seeing, could you add an example cloud configuration that reproduces the issue here, please?

Once you've done so, please move this bug back to New and we'll take another look at it.

Thanks again!

Dan

[Anisse Astier (anisse)]

Here is an example:

mounts:
  - [ '/dev/sr0', '/mnt/Cdrom Drive', auto, 'uid=1000,gid=1000', '0', '0' ]

Then after boot:

# ls /mnt/
'Cdrom Drive'
# tail -n1 /etc/fstab
/dev/sr0 /mnt/Cdrom Drive auto uid=1000,gid=1000,comment=cloudconfig 0 0
# mount /mnt/Cdrom\ Drive/
mount: /etc/fstab: parse error at line 5 -- ignored
mount: /mnt/Cdrom Drive/: can't find in /etc/fstab.

If I work around it like this:
mounts:
  - [ '/dev/sr0', '/mnt/Cdrom\040Drive', auto, 'uid=1000,gid=1000', '0', '0' ]

Then after boot:

# ls /mnt/
'Cdrom\040Drive'
# tail -n1 /etc/fstab
/dev/sr0 /mnt/Cdrom\040Drive auto uid=1000,gid=1000,comment=cloudconfig 0 0
# mount /mnt/Cdrom\ Drive/
mount: /mnt/Cdrom Drive: mount point does not exist.
# mount /mnt/Cdrom\\040Drive/
mount: /mnt/Cdrom\040Drive/: can't find in /etc/fstab.

[Dan Watkins (oddbloke)]

Thanks for the update, Anisse! Would you be interested in working on a fix for this?

[Anisse Astier (anisse)]

Hi Dan,

I'm afraid the Canonical CLA is too much work to do this on my work time for a single drive-by contribution. Maybe if I find time on my own, but I doubt it. I could however point a future contributor to what I've found:

 - fstab entries are space or tab separated according to the man page. Some implementations (musl getmntent) consider any whitespace matching isspace() to be a correct separator.
 - To be more complete, I'd escape any non-printable ascii character. It might means escaping utf-8 wide characters, but that would

[Anisse Astier (anisse)]

[continued, sorry]
… be ok. This is a complex issue with interaction between the python code in cloud-init, the filesystem charset, and the the mount parsing code of fstab; but it shouldn't be insurmountable.

Regards,

Anisse

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/3603