WSL2 - X11

Here are some scripts to automate the running Linux X11 applications in WSL2 on the Windows 10 Host. The applications run on an X11 Server running natively on the Windows Host.

The problem

After the upgrade to the WSL2, the Linux X11 applications could not connect to the X11 Windows Server, using DISPLAY=:0.0 or DISPLAY=localhost:0.0 due to the fact that WSL2 is based on containers, and for that reason each installed distribution is running under Hyper-V as a diffenent host.

So localhost do not refer to the same thing when it is used in the Container/WSL Host or the Windows Host.

The Windows Host has its own IP and the Container/WSL Host is assigned a dynamic IP by the Windows host in the 'Ethernet adapter vEthernet (WSL)' network, (see WSL/issues/4793, WSL/issues/4619 ). You can use ipconfig.exe to see networks and the IPs.

The Windows Host has also at least one IP in the vEthernet WSL network. The IP of the nameserver that is stored in /etc/resolv.conf of the distribution, is one of them. The Container/WSL Host can refer to the Windows Host with this IP.

If you happen to have installed a second Linux, (eg a Debian and an Ubuntu), then both of them are given the same name and the same IP.

Following is a bash fragment to find the DISPLAY

export DISPLAY_NUMBER="0.0"
export DISPLAY=$(grep -m 1 nameserver /etc/resolv.conf | awk '{print $2}'):$DISPLAY_NUMBER

Place the lines at the begining of your .bashrc, in order to be able to run x11 apps (eg xterm) from the WSL command line.

The automation

For the time being the files work with the VcXsrv Windows X Server and launch a kde desktop. The installed Distro is a Debian/GNU Linux

Prerequisites

• Install WSL2 and the Debian distribution.

• Update Debian and install kde-desktop, net-tools, dbus, dnsutils etc.

• Install VcXsrv Windows X Server in the default directory "C:\Program Files\VcXsrv". If you install it in another directory then you have to update the install_files.sh below, before the installation.

Installation

• Download the files install.bat and install_files.sh by using Right-click -> Save link as, overwriting previous downloads and keeping the names, at least of the install_files.sh
• If needed, change install_files.sh
  • If VcXsrv hasn't been installed in the default directory, then change the XSRV variable.
  • If you want to run another desktop environment, change the here document that creates the start_<NAME>.sh, that starts the X clients. After the installation the file is located in WSL home and can be changed later.
  • If you have installed arkane-systems/genie, in order to have systemd then uncomment the GENIE variable
• Run install.bat as Administrator.
• After the installation there are
  • a file launch_debian.bat in your Windows home directory
  • a file launch_debian.sh" in your WSL home
  • a file start_debian.sh" in your WSL home that starts the X clients.

How to Auto Start

• If you want the windowed Desktop Environment to be started when your login then create a symlink (short-cut) of the "launch_debian.bat", cut it, go to your Startup directory. (Win-X -> Run -> shell:startup) and paste it there. The same shortcut can be placed in the desktop for easy access.

Version: 2.0.4