feat: add virtual machine scan command

[masahiro331]

Description

Add new scanner for virtual machine image.

$ trivy vm 

Scan a virtual machine image

Usage:
  trivy vm [flags] VM_IMAGE

Examples:
  # Scan your AWS AMI
  $ trivy vm ami:${your_ami_id}

  # Scan your AWS EBS snapshot
  $ trivy vm ebs:${your_ebs_snapshot_id}

Architecture

Support Filesystem

• XFS
• EXT4
• others....

Support Virtual Machine Image

• Raw Image
• VMDK
• VHD
• VHDX
• qcow2
• others...

Support partition disk driver

• Master boot record
• GUID partition table
• Extended Master boot record

Support LVM

• lvm

Issue

• Support for VM image scanning #2988

Add parse libraries

• Parse XFS (https://github.com/masahiro331/go-xfs-filesystem)
• Parse EXT4 (https://github.com/masahiro331/go-ext4-filesystem)
• Parse Disk partition (https://github.com/masahiro331/go-disk)
• Parse VMDK (https://github.com/masahiro331/go-vmdk-parser)
• Parse EBS (https://github.com/masahiro331/go-ebs-file)

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).

[knqyf263]

AMI scanning (EBS snapshot)

AMI ID	AMI name	Status	Note
ami-0c0000ceb18c73b8a	Red Hat Enterprise Linux 9	✅
ami-06220be3176081cf0	Red Hat Enterprise Linux (RHEL) 7 (HVM)	✅
ami-076309742d466ad69	Amazon Linux 2 AMI (HVM) - Kernel 5.10	✅
ami-034a7d2833172671e	Amazon Linux 2 AMI (HVM) - Kernel 4.14	✅
ami-0caef02b518350c8b	Ubuntu Server 22.04 LTS	✅
ami-06148e0e81e5187c8	Ubuntu Server 20.04 LTS	✅
ami-0a5b5c0ea66ec560d	Debian 11	✅
ami-0b4c74d41ee4bed78	CentOS 7 (x86_64) - with Updates HVM	❌	bootable partition
ami-0fb02f20850e23fd0	SUSE Linux Enterprise Server 15	✅
ami-0b3d1809cc222924a	AlmaLinux OS 8	✅
ami-0e2bc7a3ca89f5d06	Rocky Linux 8	❌	bootable partition

Script

https://gist.github.com/knqyf263/560020453511fe8107e2e9796fffbbd6#file-ami-snapshot-sh

[knqyf263]

I figured out why it failed on CentOS/Rocky Linux.

The images successfully scanned were GPT-partitioned.

[ec2-user@ip-172-31-32-24 ~]$ sudo fdisk -l /dev/xvda
Disk /dev/xvda: 8 GiB, 8589934592 bytes, 16777216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: DA90AB95-8C11-4BAE-9157-C48213FBAD0C

Device       Start      End  Sectors Size Type
/dev/xvda1    4096 16777182 16773087   8G Linux filesystem
/dev/xvda128  2048     4095     2048   1M BIOS boot

Partition table entries are not in disk order.

Rocky Linux is MBR-partitioned.

[rocky@ip-172-31-46-195 ~]$ sudo fdisk -l
Disk /dev/xvda: 10 GiB, 10737418240 bytes, 20971520 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xec07056d

Device     Boot Start      End  Sectors Size Id Type
/dev/xvda1 *     2048 20971486 20969439  10G 83 Linux

We should not just skip bootable partition. We should skip only MBR and BIOS boot partition, not EFI System Partition (ESP).

[knqyf263]

Fixed in 6c7f970. I confirmed CentOS and Rocky Linux work now.

[knqyf263]

AMI scanning (EBS snapshot) after the fix

AMI ID	AMI name	Status	Note
ami-0c0000ceb18c73b8a	Red Hat Enterprise Linux 9	✅
ami-06220be3176081cf0	Red Hat Enterprise Linux (RHEL) 7 (HVM)	✅
ami-076309742d466ad69	Amazon Linux 2 AMI (HVM) - Kernel 5.10	✅
ami-034a7d2833172671e	Amazon Linux 2 AMI (HVM) - Kernel 4.14	✅
ami-0caef02b518350c8b	Ubuntu Server 22.04 LTS	✅
ami-06148e0e81e5187c8	Ubuntu Server 20.04 LTS	✅
ami-0a5b5c0ea66ec560d	Debian 11	✅
ami-0b4c74d41ee4bed78	CentOS 7 (x86_64) - with Updates HVM	✅	MBR
ami-0fb02f20850e23fd0	SUSE Linux Enterprise Server 15	✅
ami-0b3d1809cc222924a	AlmaLinux OS 8	✅
ami-0e2bc7a3ca89f5d06	Rocky Linux 8	✅	MBR

Script

https://gist.github.com/knqyf263/560020453511fe8107e2e9796fffbbd6#file-ami-snapshot-sh

[knqyf263]

Now it's all green 🎉🎉 🎉 🎉 🎉