Remove disk name filter for Virtual Machine Image scan

[yusuke-koyoshi]

trivy vm only scans specific disk names for snapshots.

trivy/pkg/fanal/walker/vm.go

Lines 22 to 30 in 3be5e6b

	var requiredDiskName = []string{
	"Linux", // AmazonLinux image name
	"p.lxroot", // SLES image name
	"primary", // Common image name
	"0", // Common image name
	"1", // Common image name
	"2", // Common image name
	"3", // Common image name
	}

OS packages are located in the root volume, but programming language project files may exist outside of the root volume, so it is not advisable to limit them to specific volume names.

[knqyf263]

@masahiro331 Wdyt?

[masahiro331]

@yusuke-koyoshi
If they are divided by logical volumes, which I believe is the case, but are they divided by physical volumes?

[masahiro331]

At least an AMI is composed of a single physical volume.

[yusuke-koyoshi]

@masahiro331
An AMI consists of a single physical volume, but multiple EBS volumes can be attached to EC2.
When you scan EC2 instance, you must scan all attached EBS volumes.

[yusuke-koyoshi]

@masahiro331
There can be cases where multiple EBS volumes are attached and the partition names are something other than defined.
I don't think there is a need to restrict partition names, but why do we do so?

[masahiro331]

Since there are hard disks for backup and journaling, the policy was to ignore volumes that are not known.