List disks fails with non-disk scsi devices

[Chris Sanders]

Error opening non disk device

# ./actions/list-disks
  Failed to find physical volume "/dev/cdrom".
Traceback (most recent call last):
  File "./actions/list-disks", line 46, in <module>
    not ceph.utils.is_pristine_disk(dev)):
  File "lib/ceph/utils.py", line 890, in is_pristine_disk
    f = open(dev, 'rb')
OSError: [Errno 123] No medium found: '/dev/sr0'

Devices on the system:
brw-rw---- 1 root disk 8, 0 Jun 23 14:24 /dev/sda
brw-rw---- 1 root disk 8, 1 Jun 23 14:25 /dev/sda1
brw-rw---- 1 root disk 8, 16 Jun 23 14:24 /dev/sdb
brw-rw---- 1 root disk 8, 32 Jun 23 14:24 /dev/sdc
brw-rw---- 1 ceph ceph 8, 33 Jun 23 14:24 /dev/sdc1
brw-rw---- 1 ceph ceph 8, 34 Jun 23 14:24 /dev/sdc2
crw-rw---- 1 root cdrom 21, 0 Jun 23 14:24 /dev/sg0
crw-rw---- 1 root disk 21, 1 Jun 23 14:24 /dev/sg1
crw-rw---- 1 root disk 21, 2 Jun 23 14:24 /dev/sg2
crw-rw---- 1 root disk 21, 3 Jun 23 14:24 /dev/sg3
crw------- 1 root root 10, 231 Jun 23 14:24 /dev/snapshot
brw-rw---- 1 root cdrom 11, 0 Jun 23 14:24 /dev/sr0

This is on a fresh Bionic:
Distributor ID: Ubuntu
Description: Ubuntu 18.04.2 LTS
Release: 18.04
Codename: bionic
Kernel: 4.15.0-52-generic

At the very least, opening the device should probably have a try/except possibly keeping a list of devices that failed to read.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Alexandros Soumplis (<email address hidden>) on branch: master
Review: https://review.opendev.org/699398
Reason: Closed in favor of https://review.opendev.org/#/c/699404/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/699398
Committed: https://git.openstack.org/cgit/openstack/charm-ceph-osd/commit/?id=df8f477cd79ddf59309d130cf8f5dce3422a7fa5
Submitter: Zuul
Branch: master

commit df8f477cd79ddf59309d130cf8f5dce3422a7fa5
Author: Alexandros Soumplis <email address hidden>
Date: Tue Dec 17 13:48:07 2019 +0200

    Ignore devices with OSError

    This bug handles OSError when trying to read from CDrom devices with no
    disc in the is_pristine_disk function which makes the run-action
    list-disks to fail.

    Change-Id: I5e86895d1adff3f95c7feb5ed0f78b998c28ed1f
    Depends-On: I951897a699305604821f2c910ee9ea91582c4e40
    Closes-Bug: #1833857
    Signed-off-by: Alexandros Soumplis <email address hidden>