VirtualBox support is now limited to 1KB of user data

Bug

Operating System Version

Flatcar latest main.

Ignition Version

2.24.0 because of Flatcar, but the root cause is outside Ignition, and the provider hasn't changed in years.

Environment

VirtualBox 7.2.8.

Expected Behavior

You can provide up to 128KB of user data on Linux, as documented by FCOS and noted in #1269.

Actual Behavior

VBoxManage returns a VERR_TOO_MUCH_DATA error when you set more than 1KB of data.

Reproduction Steps

Create a VirtualBox VM and try to set the guest property with more than 1KB of data.

$ ls -l config.ign 
-rw-r--r-- 1 chewi users 1084 Apr 29 09:18 config.ign

$ VBoxManage guestproperty set 42e89654-5b5f-48a1-959b-616575bd2349 /Ignition/Config "$(< config.ign)"
VBoxManage: error: VERR_TOO_MUCH_DATA
VBoxManage: error: Details: code NS_ERROR_INVALID_ARG (0x80070057), component SessionMachine, interface IMachine, callee nsISupports
VBoxManage: error: Context: "SetGuestPropertyValue(Bstr(pszName).raw(), Bstr(pszValue).raw())" at line 151 of file VBoxManageGuestProp.cpp

Other Information

This is mostly a heads up, as there isn't much you can do beyond fixing the FCOS docs or maybe asking VirtualBox to increase the limit. Implementing gzip decompression will help a little but not much.

128KB was allowed at the time #1269 was implemented, but this changed to 128 bytes in VirtualBox/virtualbox@cffda6a7804963ef3448288d663b1f3c30872444 and that was later raised to 1KB in VirtualBox/virtualbox@32a8ce091ea12b8e2ab792546215c51bb8a61293.

Start with the FCOS VirtualBox provisioning documentation linked in the issue, then review the referenced VirtualBox commits and the reproduction command. Done would require an agreed project action, such as a documentation correction or an upstream resolution; the issue currently identifies no Ignition file or test to change.