Added disks extended attributes

[geektophe]

This patch brings some of the physical and virtual drive attributes as custom_fields to the disks inventory.

The goal is to have this information present to ease disks maintenance when a drive becomes unavailable and its attributes can't be read anymore from the RAID controller.

It also helps to standardize the extended disk attributes across the different manufacturers.

As the disk physical identifers were not available under the correct format (hexadecimal format using the xml output as opposed as X:Y:Z format using the default list format), the command line parser has been refactored to read the list format, rather than xml one in the omreport raid controller parser.

As the custom fields have to be created prior being able to register the disks extended attributes, this feature is only activated using the --process-virtual-drives command line parameter, or by setting process_virtual_drives to true in the configuration file.

The custom fields to create as DCIM > inventory item Text are described below.

NAME            LABEL                      DESCRIPTION
mount_point     Mount point                Device mount point(s)
pd_identifier   Physical disk identifier   Physical disk identifier in the RAID controller
vd_array        Virtual drive array        Virtual drive array the disk is member of
vd_consistency  Virtual drive consistency  Virtual disk array consistency
vd_device       Virtual drive device       Virtual drive system device
vd_raid_type    Virtual drive RAID         Virtual drive array RAID type
vd_size         Virtual drive size         Virtual drive array size

In the current implementation, the disks attributes ore not updated: if a disk with the correct serial number is found, it's sufficient to consider it as up to date.

To force the reprocessing of the disks extended attributes, the --force-disk-refresh command line option can be used: it removes all existing disks to before populating them with the correct parsing. Unless this option is specified, the extended attributes won't be modified unless a disk is replaced.

It is possible to dump the physical/virtual disks map on the filesystem under the JSON notation to ease or automate disks management. The file path has to be provided using the --dump-disks-map command line parameter.