Get disk format from template on VMware, fixes bsc#1171349

[spiarh]

Why is this PR needed?

Fixes https://bugzilla.suse.com/show_bug.cgi?id=1171349

What does this PR do?

This commit makes it possible to inherit the format of a disk from the template, before this, only
"Thin provision" templates could be cloned as these are the default terraform values.

• Thick Provision Lazy Zeroed (default)
• Thick Provision Eager Zeroed
• Thin Provision

Signed-off-by: lcavajani lcavajani@suse.com

Info for QA

To use Thick Provisoning Lazy Zeroed (default)

1. Create Template with Thick Provisoning Lazy Zeroed as format for the disk
2. Clone from this template

$ INSTANCE_NAME="test-disks-lcava-master-0"
$ govc device.info -json=true -vm /PROVO/vm/$INSTANCE_NAME disk-1000-0 | jq '.Devices[].Backing | {ThinProvisioned, EagerlyScrub}'
{
  "ThinProvisioned": false,
  "EagerlyScrub": null
}

To use Thick Provisoning Eager Zeroed (default)

1. Create Template with Thick Provisoning Eager Zeroed as format for the disk
2. Clone from this template

⚠️ didn't show as eagerly scrubbed, need to investigate...

EDIT: I've found out we end up with lazy-zeroed when the size of the disk is changed, which is what we do, I've created an issue upstream: hashicorp/terraform-provider-vsphere#1078

If it's by design and not a bug, I will update the doc

$ INSTANCE_NAME="test-disks-lcava-master-0"
$ govc device.info -json=true -vm /PROVO/vm/$INSTANCE_NAME disk-1000-0 | jq '.Devices[].Backing | {ThinProvisioned, EagerlyScrub}'
{
  "ThinProvisioned": false,
  "EagerlyScrub": null
}

To use Thin Provisoning:

1. Create Template with Thin Provisioning as format for the disk
2. Clone from this template

$ INSTANCE_NAME="test-disks-lcava-master-0"
$ govc device.info -json=true -vm /PROVO/vm/$INSTANCE_NAME disk-1000-0 | jq '.Devices[].Backing | {ThinProvisioned, EagerlyScrub}'
{
  "ThinProvisioned": true,
  "EagerlyScrub": null
}

Status BEFORE applying the patch

It's not possible to use something else as the default Thin provisioning.

Status AFTER applying the patch

It's now possible to use the three formats above.

Docs

SUSE/doc-caasp#796

Merge restrictions

(Please do not edit this)

We are in v4-maintenance phase, so we will restrict what can be merged to prevent unexpected surprises:

What can be merged (merge criteria):
    2 approvals:
        1 developer: code is fine
        1 QA: QA is fine
    there is a PR for updating documentation (or a statement that this is not needed)

[innobead]

cc @c3y1huang @jenting @maximenoel8 @cclhsu @suseclee

[spiarh]

Related to https://github.com/SUSE/avant-garde/issues/1564

[suseclee]

Tested results

image                                             template                                          VM
-----------------------------------------------------------------------------------------------------------------------------
lcavajani-guestinfo-nothin               Thick Provision Lazy Zeroed             Thick Provision Lazy Zeroed
lcavajani-guestinfo-nothin-eago          Thick Provision Eager Zeroed            Thick Provision Lazy Zeroed

Thick provisioned lazy zeroed: Both eagerly_scrub and thin_provisioned should be set to false.
Thick provisioned eager zeroed: eagerly_scrub should be set to true, and thin_provisioned should be set to false.
Thin provisioned: eagerly_scrub should be set to false, and thin_provisioned should be set to true.

lcavajani-guestinfo-nothin got

eagerly_scrub    = false
thin_provisioned = false

lcavajani-guestinfo-nothin-eago got

eagerly_scrub    = true
thin_provisioned = false

Vmware template default disk type cannot be changed as Ludo already mentioned about the bug. I feel like the VM is Thick Provision Eager Zeroed the last line of table because it took significantly took more time than layzy_zero or thin provisioning. I think that is because it is scrubbing old data. Anyway this is Terraform's bug as Ludo already mentioned the upstream issue in the bug.

It looks good to me.

[spiarh]

I still don't have an answer from upstream regarding Thick Provision Eager Zeroed so I have explained in the documentation how to proceed if one wants to use Thick Provision Eager Zeroed.

This is just to use the exact template size as values for master_disk_size and worker_disk_size.

[spiarh]

This is ready for release.

[suseclee]

Codes have not been changed a lot prior to my previous review.
LGTM