Handle undef value in lvm::logical_volume

[riton]

When an undef value is passed as lvm::logical_volume name, mkfs is called with unwanted command line like

Error: Execution of 'mkfs.ext4 /dev/rootvg/' returned 1: mke2fs 1.42.9 (28-Dec-2013)
/dev/rootvg/ is not a block special device.
Proceed anyway? (y,n)
Error: /Stage[main]/Main/Lvm::Logical_volume[undef]/Filesystem[/dev/rootvg/]/ensure: change from absent to present failed: Execution of 'mkfs.ext4 /dev/rootvg/' returned 1: mke2fs 1.42.9 (28-Dec-2013)
/dev/rootvg/ is not a block special device.
Proceed anyway? (y,n)

This does not break anything, but we're here protected by mkfs that asks for confirmation (this fails in batch mode).

This patch only introduces a stupid test to check that $name isn't  undef.

My software versions:

• CentOS 7
• puppet v3.7.2
• ruby 2.0.0p353

[bmjen]

Thanks @riton! Is it possible to get a sample manifest that would produce this error?

[underscorgan]

@riton I don't understand how this error could possibly happen, name is required :\

[riton]

I know that nameis required. I found this error with a manifest like:

class myclass($lv_name)
{
    ::lvm::logical_volume { $lvname:
        ensure            => present,
        volume_group      => 'rootvg',
        size              => '1G',
        fs_type           => 'ext4',
        mountpath         => '/tmp',
        mountpath_require => false
    }
}
class { '::myclass': lv_name => 'foo' }

A simple typo in my variable name ($lvname instead of $lv_name) scares me when I saw that mkfs was called on /dev/${vg_name}/.

This could also happen if someone does not do proper user input validation in its manifest like in:

class myclass2($lv_name = undef) 
{
    ::lvm::logical_volume { $lv_name:
      [...]
     }
}
class { '::myclass2': }

I know that this is not supposed to happen, but considering that the final process is mkfs and that it can possibly break things on the system, I think it's worth a simple test for undefined value.

[bmjen]

@riton You are correct, a situation like the one you listed could definitely pass through an undef $name. I will merge.

[underscorgan]

o.O

Good catch, @riton !