Obscure error when attempting to create instance with name longer than 46 characters

[joes]

Obscure error when attempting to create instance with name longer than 46 characters

To Reproduce

When name is 47 characters long or more: FAIL

$ multipass launch -v --name "o1234567890123456789012345678901234567890123456" focal
[2022-09-05T11:52:34.078] [error] [lxd request] Operation completed with error: (400) Failed to run: forklimits limit=memlock:unlimited:unlimited fd=3 -- /snap/lxd/23537/bin/qemu-system-x86_64 -S -name o1234567890123456789012345678901234567890123456 -uuid 94d09ee5-a3d6-4091-9ecb-9d2ed3026390 -daemonize -cpu host,hv_passthrough -nographic -serial chardev:console -nodefaults -no-user-config -sandbox on,obsolete=deny,elevateprivileges=allow,spawn=allow,resourcecontrol=deny -readconfig /var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.conf -spice unix=on,disable-ticketing=on,addr=/var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.spice -pidfile /var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.pid -D /var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.log -smbios type=2,manufacturer=Canonical Ltd.,product=LXD -runas lxd: : Process exited with non-zero value 1
launch failed: Operation completed with error: (400) Failed to run: forklimits limit=memlock:unlimited:unlimited fd=3 -- /snap/lxd/23537/bin/qemu-system-x86_64 -S -name o1234567890123456789012345678901234567890123456 -uuid 94d09ee5-a3d6-4091-9ecb-9d2ed3026390 -daemonize -cpu host,hv_passthrough -nographic -serial chardev:console -nodefaults -no-user-config -sandbox on,obsolete=deny,elevateprivileges=allow,spawn=allow,resourcecontrol=deny -readconfig /var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.conf -spice unix=on,disable-ticketing=on,addr=/var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.spice -pidfile /var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.pid -D /var/snap/lxd/common/lxd/logs/multipass_o1234567890123456789012345678901234567890123456/qemu.log -smbios type=2,manufacturer=Canonical Ltd.,product=LXD -runas lxd: : Process exited with non-zero value 1

When name is 46 characters long or less: OK

$ multipass launch -v --name "o123456789012345678901234567890123456789012345" focal
Launched: o123456789012345678901234567890123456789012345

Expected behavior

A human-friendly error message, such as: "Invalid name - name is longer than 46 characters"

Additional info

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.1 LTS"

$ multipass version
multipass   1.10.1
multipassd  1.10.1

$ multipass get local.driver
lxd

$ lxd version
5.5

[luis4a0]

Hi @joes, thanks for reporting. This is a limitation of LXD only. We are working in making failures more verbose when using LXD as backend. We will keep this one in mind.

[sharder996]

Rather than add more restrictions and create backend specific logic, one way of fixing this would be to use UUIDs to internally identify instances and have the name just be a label. See #255