detaching disk issue: "error detaching VM Disk: Could not detach sdc from"

[pumpkineggs]

Description
While detaching disk from VM in some cases an error could be thrown like: "error detaching VM Disk: Could not detach sdc from ".

To Reproduce

1. Create user with name sdaniel
2. Create a VM owned by the user and attach scsi disk (sda).
3. Try to detach the disk on running VM.
4. Get an error.

Expected behavior
Disk detached, no error thrown.

Details

• Affected Component: vmm_mad
• Hypervisor: KVM
• Version: 5.10.x

Additional context
We noticed that "detach_disk" script (vmm_mad/remotes/kvm/detach_disk) should use a more efficient way to check whether a disk detached or not.
While detaching disk from VM in some cases an error could be thrown like: "error detaching VM Disk: Could not detach sdc from ".
But in fact, the disk has been detached from the VM and it can be confirmed via "virsh dumpxml" command.
There is a piece of code in the script:

virsh --connect $LIBVIRT_URI dumpxml $DOMAIN | grep $TARGET > /dev/null 2>&1

if [ $? -eq 0 ] ; then
    error_message "Could not detach $TARGET from $DOMAIN"
    exit -1
fi

Here we have grep $TARGET part where $TARGET turns into a device name (i.e. vda, sda, sdc, etc...).
Let's say we are trying to detach a scsi disk "sda", so the script will run a check with grep sda.
And an interesting part is if the owner of the VM is a user with a name: sdaniel, which is reflected in the domain xml metadata section, grep will return some data and if [ $? -eq 0 ] ; piece will return an error and script will exit with rc=-1 in spite the disk has been detached from the domain.

Proposed changes for the script:
virsh --connect $LIBVIRT_URI dumpxml $DOMAIN | grep dev=\'$TARGET\' > /dev/null 2>&1
Just be more specific about what to grep and extend the regexp to dev=\'$TARGET\'.

Progress Status

• Branch created
• Code committed to development branch
• Testing - QA
• Documentation
• Release notes - resolved issues, compatibility, known issues
• Code committed to upstream release/hotfix branches
• Documentation committed to upstream release/hotfix branches

[rsmontero]

merged