WSL rootfs on newer OS builds is no longer "%LOCALAPPDATA%\lxss"

[BR0kEN-]

Vagrant version

Vagrant 2.0.2

Host operating system

Windows 10 (version 1709, build 16299.125).

Expected behavior

Vagrant is to detect current WSL container and compute a proper path to it.

Actual behavior

Vagrant handles only the WSL that is installed via lxrun.

References

• Location of WSL rootfs filesystem for post - Fall Creator's Update installations microsoft/WSL#2578
• Plugin is broken in WSL after Windows 10 Fall Creators Update berkshelf/vagrant-berkshelf#323
• https://github.com/BR0kEN-/cikit/tree/issues/52/docs/vagrant/wsl
• Error when installing Arch Linux rootfs on Windows 10 Fall Creators Update RoliSoft/WSL-Distribution-Switcher#69

Additional information

Before the 16215 build of Windows, there was a way to install a WSL using lxrun. After mentioned build this way has been deprecated and, since then, it's recommended to use Microsoft Store for installing a WSL. Moreover, since that version, you can have multiple instances of Linux subsystem.

When the installation is done by lxrun /install then rootfs of a WSL will be in %LOCALAPPDATA%\lxss and Vagrant will operate correctly since its codebase relies on this location (https://github.com/hashicorp/vagrant/blob/v2.0.1/lib/vagrant/util/platform.rb#L286-L289).

When the installation is done from the Microsoft Store, then rootfs of a WSL will be in %LOCALAPPDATA%\Packages\<WSL_ID>\LocalState. Pay your attention at the <WSL_ID> token in the path which is completely dynamic.

The path of the particular container can be obtained from the registry at HKCU:\Software\Microsoft\Windows\CurrentVersion\Lxss - a listing of installed subsystems.

For instance, using the following PowerShell script, the path of default subsystem can be gained.

$WSLREGKEY="HKCU:\Software\Microsoft\Windows\CurrentVersion\Lxss"
$WSLDEFID=(Get-ItemProperty "$WSLREGKEY").DefaultDistribution
$WSLFSPATH=(Get-ItemProperty "$WSLREGKEY\$WSLDEFID").BasePath
New-Item -ItemType Junction -Path "$env:LOCALAPPDATA\lxss" -Value "$WSLFSPATH\rootfs"

[BR0kEN-]

@chrisroberts, I made a PR based on microsoft/WSL#2578 (comment) and would appreciate if you could take a look (since you were the initial author of WSL integration).

[AsharLohmar]

Thanks for the patch it (kind of) worked.

I'm on:

• Microsoft Windows [Version 10.0.16299.192]
• Ubuntu installed from store
• Vagrant 2.0.1 (installed only the "*.deb" file on/in Ubuntu)

In the "/opt/vagrant/embedded/gems/gems/vagrant-2.0.1/lib/vagrant/util/powershell.rb" I had to change all the "powershell" references in "powershell.exe", otherwise vagrant would've complain that there was no powershell in the PATH.

[BR0kEN-]

@AsharLohmar, you can just create a symlink. Example: https://github.com/BR0kEN-/cikit/blob/6f1b572e3f3a779a7a776e919c39e2a6cca77643/docs/_documentation/install-on-wsl/wsl-provision.sh#L14-L27

[AsharLohmar]

That's a good advice . Thanks

[atorstling]

Can I build this release for testing somehow without tainting my local WSL env? How do you build a deb from source? Thanks

[BR0kEN-]

@atorstling, download deb from https://releases.hashicorp.com/vagrant/2.0.1/vagrant_2.0.1_x86_64.deb and patch it with https://raw.githubusercontent.com/BR0kEN-/cikit/master/docs/_documentation/install-on-wsl/patches/vagrant-2.0.1-issue-9298.patch.

cd ~
wget -q https://releases.hashicorp.com/vagrant/2.0.1/vagrant_2.0.1_x86_64.deb
sudo dpkg -i vagrant_2.0.1_x86_64.deb
rm vagrant_2.0.1_x86_64.deb
cd /opt/vagrant/embedded/gems/gems/vagrant-2.0.1
sudo wget -q https://raw.githubusercontent.com/BR0kEN-/cikit/master/docs/_documentation/install-on-wsl/patches/vagrant-2.0.1-issue-9298.patch
sudo patch -p1 < vagrant-2.0.1-issue-9298.patch

https://github.com/BR0kEN-/cikit/blob/6f1b572e3f3a779a7a776e919c39e2a6cca77643/docs/_documentation/install-on-wsl/wsl-provision.sh#L133-L161

[atorstling]

@BR0kEN- Ok, I patched 2.0.2 and symlinked powershell, but I get the Vagrant is unable to determine WSL instance you are currently in because Windows registry has no information about it at "HKCU:\Software\Microsoft\Windows\Current Version\Lxss" error. I do have a reg structure for the LSW, see attachment. I also ran vagrant with debug and got the following:

DEBUG wsl: Checking whether the "/mnt/c/Users/Alexander/rootfs" is a root VolFS mount of current WSL instance.
 WARN wsl: Windows registry has an information about WSL instance with the "/mnt/c/Users/Alexander/rootfs" base path that is no longer exist or broken.
DEBUG wsl: Checking whether the "/mnt/trstling/AppData/Local/Packages/CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc/LocalState/rootfs" is a root VolFS mount of current WSL instance.
 WARN wsl: Windows registry has an information about WSL instance with the "/mnt/trstling/AppData/Local/Packages/CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc/LocalState/rootfs" base path that is no longer exist or broken.
ERROR warden: Error occurred: Vagrant is unable to determine WSL instance you are currently in because Windows
registry has no information about it at "HKCU:\Software\Microsoft\Windows\Current
Version\Lxss".

The "/mnt/trstling" path looks iffy. I don't think it exists. Actually, looking closer into it the issue seems to be that you do split(" "), and my username has spaces in it.

lxss.reg.txt

[BR0kEN-]

Yeah, @atorstling, well noticed! I'll do an update on this today.

[atorstling]

@BR0kEN- Great, thanks!