cloud-init requires ability to mount iso9660

[Ben Howard]

Azure fails to provision Snappy:

Jul 7 14:37:24 localhost [CLOUDINIT] util.py[DEBUG]: Running command ['mount', '-o', 'ro,sync', '-t', 'iso9660', '/dev/sr0', '/tmp/tmpek9fl3m2'] with allowed return codes [0] (shell=False, capture=True)
Jul 7 14:37:24 localhost [CLOUDINIT] util.py[DEBUG]: Failed mount of '/dev/sr0' as 'iso9660': Unexpected error while running command.#012Command: ['mount', '-o', 'ro,sync', '-t', 'iso9660', '/dev/sr0', '/tmp/tmpek9fl3m2']#012Exit code: 32#012Reason: -#012Stdout: ''#012Stderr: 'mount: wrong fs type, bad option, bad superblock on /dev/sr0,\n missing codepage or helper program, or other error\n\n In some cases useful info is found in syslog - try\n dmesg | tail or so.\n'

[Ben Howard (darkmuggle-deactivatedaccount)]

I might add that this will break OpenStack clouds and any cloud-config system.

[Ben Howard (darkmuggle-deactivatedaccount)]

Calling this invalid. Nested exceptions in cloud-init were hiding the root cause.