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On 07/01/2014 23:41, Jesse Benedict
wrote:
I am setting up my own dev environment, but
in the mean-time I would like to propose the following:
PROPOSAL
Auto Ejection of All Mounted CDs
PURPOSE
To make application of patches/hotfixes
easier in large environments where ISO images may be mounted
to VMs
TARGET COMPONENTS
XE command line, ie:
xe eject-all-isos
XenCenter (API call to eject-all-isos)
OR in our XSxxxxx.upadate package format as
a pre-req script.
Looks very sensible and useful.
However, when scripting xe calls,
"params=some,list,of,parameter,you,are,interested,in" and
"--minimal" are your friends. See inline below.
EXAMPLE CODE
An example is a file I wrote,
xe-eject-all-isos (using Bash for simplicity):
#!/bin/bash
echo "CHECKING"
# Get list of VMs from xe vm-list -- specifically
UUID
VMLIST=`xe vm-list is-control-domain=false | grep
uuid | awk '{print $5}'`
VMLIST=$(xe vm-list is-control-domain=false params=uuid --minimal |
tr ',' ' ')
should do that without grep or awk, (but sadly still using tr)
(Note for Ring3: It would be lovely for shell scripts to get a
space-delimited list from --minimal rather than comma-delimited, but
I cant see a convenient option for that)
# Loop through list and see if a DVD/CDROM is
present
for VMUUID in $VMLIST
do
VMNAME=`xe vm-list uuid=$VMUUID | grep
"name-label" | awk '{print $4}'`
VMNAME="$(xe vm-list uuid=$VMUUID params=name-label --minimal)"
You need to quote in case the VM name has spaces in.
ISOMOUNTED=`xe vm-cd-list uuid=$VMUUID | grep
"empty" | awk '{print $4}'`
vm-cd-list doesn't take a uuid parameter, but then again doesn't
appear to function correctly.
Note for Ring3: This appears to be a bug (tested on XS 6.2 SP1).
`xe vm-cd-list uuid=` tab completes to VM uuids, but rejects them,
and the help description doesn't mention uuid= as a valid
parameter. The help text indicates that it accepts the meta-option
"vm=", which works for vm names, but not for vm uuids. Running a
bare `xe vm-cd-list` insists on having the '--multiple' option, and
(when provided) hands back a list of vbd uuids of cds for each vm.
Also, unlike some of the other $FOO-list options, vm-cd-list doesn't
appear to like "params=".
Jesse:
Best as I can tell, you probably want:
ISOMOUNTED=$(xe vm-cd-list vm=$VMNAME | grep "empty" | awk '{print
$4})
if [ "$ISOMOUNTED" = "false" ] ; then
xe vm-cd-eject uuid=$VMUUID
xe vm-cd-eject also tab completes uuid= to VM uuids but rejects
them, and yet accepts vm=$VMNAME
echo "UNMOUNTED DVD/CD IMAGE FROM
$VMNAME"
fi
done
# END
echo "DONE"
Sincerely,
I occurs to me that all of this can be achieved with the single call
xe vm-cd-eject --multiple
So long as you are happy to accept
"operation failed on $VMUUID: Operation could not be performed
because the drive is empty"
for PV guests, and
"operation failed on $VMUUID: INTERNAL_ERROR: [
Cli_util.Cli_failure("No CDs found") ]"
for HVM guests, when CDs are not actually present in the first
place. (Again, tested on XS 6.2 SP1)
~Andrew
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