mount option can`t set permissions

[Björn Dieding]

mounts:
 - [ ephemeral0, /mnt/ephemeral, auto, "defaults" ]
 - [ swap, none, swap, sw, "0", "0" ]

will create this error

[ec2-user@ip-10-234-85-230 ~]$ mkdir -p /mnt/ephemeral/var.live
mkdir: cannot create directory `/mnt/ephemeral/var.live': Permission denied

it looks like a chmod is not implemented

[Serge Hallyn (serge-hallyn)]

Thanks for taking the time to report this bug.

I am marking this 'low' priority, per the definition "moderate impact on a non-core application".

[Scott Moser (smoser)]

What sort of syntax would you suggest for cloud-config to set permissions on a mount?
I'm expecting that in your example you just want to have "ubuntu:ubuntu" as the ownership so that the default user could use it.

[Björn Dieding (bjoern-a)]

Yes something like this.

 - [ ephemeral0, /mnt/ephemeral, auto, "defaults", "ubuntu:ubuntu", 0755 ]

[Scott Moser (smoser)]

On Tue, 20 Dec 2011, Björn Dieding wrote:

> Yes something like this.
>
> - [ ephemeral0, /mnt/ephemeral, auto, "defaults", "ubuntu:ubuntu",
> 0755 ]

Hm... i suppose we could add a field there, but it wouldn't be ideal.
I like the fact that the fields represent exactly what is in /etc/fstab.

But any other solution would require mapping the entry to directory.

[Björn Dieding (bjoern-a)]

I do not know... it is up to you...

[Sergii Golovatiuk (sgolovatiuk)]

This issue is more serious than you think. For instance, I want to create /tmp as ephemeral. Normally, I assign 1777 permissions to /tmp to allow users to create and delete own files/directories from /tmp. That's very common for very large set of programs. If I set up tmp in cloud-init definition as

 - [ ephemeral0, /tmp, auto, 'defaults,nobootwait,noatime', '0', '2' ]

it means that permission will be 0755 every time after reboot. It makes cloud-init unusable and requires extra hacks such as creating upstart script to fix the permission on /tmp during boot process as stated at http://serverfault.com/questions/427626/how-to-mount-tmp-in-mnt-on-ec2

As a solution you should either implement as

mounts:
 ephemeral0:
  - [/tmp, auto, 'defaults,nobootwait,noatime', '0', '2' ]
  - [/tmp, "root:root, 1777]

or

[ ephemeral0, /tmp, 'defaults', '0', '2', 'ubuntu:ubuntu', '0755']

otherwise this bug makes cloud-init not very usable for mount management

[traylenator (traylenator)]

This is particularly in the way with CentOS 7 it seems where when the system reboots the boot process stops early as /tmp is not writable.

[Graham Leggett (minfrin-y)]

We just ran into this issue trying to get cloud-init to create a dedicated partition for /var/tmp. It creates the mount, but with the wrong permissions, and thus breaks the machine.

We've had to hack our config to work around the problem, which is really ugly.

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/2225