generate qemu vm uuid

[dictcp]

Background

Some application may requires the product_uuid from sysfs, OR it will be broken, eg.

• Unable to launch sysbox containers in certain KVM-based VMs. nestybox/sysbox#439
• https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/959308

The patch will generate a UUID, based of the MD5 sum of the VM name, and append as qemu --uuid parameter.
It should be safe and no impact to others usecase.

[AkihiroSuda]

For universal uniqueness, can we generate a random UUID and save it as “uuid” file in the instance dir?

lima/pkg/store/filenames/filenames.go

Lines 25 to 45 in 3aca16d

	// Filenames that may appear under an instance directory
	const (
	LimaYAML = "lima.yaml"
	CIDataISO = "cidata.iso"
	BaseDisk = "basedisk"
	DiffDisk = "diffdisk"
	QemuPID = "qemu.pid"
	QMPSock = "qmp.sock"
	SerialLog = "serial.log"
	SerialSock = "serial.sock"
	SSHSock = "ssh.sock"
	GuestAgentSock = "ga.sock"
	HostAgentPID = "ha.pid"
	HostAgentSock = "ha.sock"
	HostAgentStdoutLog = "ha.stdout.log"
	HostAgentStderrLog = "ha.stderr.log"
	// SocketDir is the default location for forwarded sockets with a relative paths in HostSocket
	SocketDir = "sock"
	)

[AkihiroSuda]

( no need to save the uuid as a file if you adopt Jan’s approach #754 (comment) )

[AkihiroSuda]

Thanks, but please sign the commit for DCO
https://github.com/apps/dco

(run git commit -a -s --amend, and make sure that the Signed-off-by: NAME <EMAIL> line with your real name is included in the commit message)

[jandubois]

To have a globally unique, but persistent (accross VM restarts) id we include both the machine id and the full path to the VM directory:

lima/pkg/limayaml/defaults.go

Line 44 in 3aca16d

sha := sha256.Sum256([]byte(osutil.MachineID() + uniqueID))

The instance name alone isn't even locally unique because you can have multiple LIMA_HOME settings on the same machine.

I would suggest to extract the sha function from limayaml.MACAddress into a separate function and also use it as input for the qemu UUID. The uniqueID passed into the function is the instance directory.

[junnplus]

@dictcp Hi, are you still working on this PR? I need it too.

[AkihiroSuda]

@junnplus Feel free to open a new PR to carry this (if you would like to)