Author: Dr. Ralf S. Engelschall
Version: 2.4.3 (2024-03-12)

Unix Environment under Windows

This is a documentation on how to setup a reasonable but opinionated Unix development environment under Microsoft Windows 10/11 (Pro edition, 64-bit mode, version ≥ 1809) with the help of the native Windows Subsystem for Linux (WSL), the Ubuntu GNU/Linux distribution, Dr. Ralf S. Engelschall's Unix dotfiles shell environment, the terminal emulator MinTTY/WSLTTY and the Docker Desktop for Windows container execution platform.

Notice: In short, the crux of this setup in contrast to the usual standard WSL setups is:

• convenient root access (password-less sudo)
• reasonably mapped home directory (/c/Users/$USER)
• essential Unix shell configurations for Bash, Vim, Vifm, TMux and Git ("dot-files")
• essential Unix shell tools (OpenSSH, RSYNC, etc)
• additional WSL shell tools (wsl-open)
• improved host terminal emulator (MinTTY/WSLTTY)
• host SSH agent with transparent access from within WSL (weasel-pageant)
• Docker and Kubernetes client CLIs
• optionally, Docker runtimes inside WSL (DockerD, Podman) or on host (Docker for Windows)
• optionally, essential programming language runtime (JavaScript/Java)

Install Windows Subsystem for Linux (WSL)

1. Ensure Windows 10/11 Professional/Enterprise, 64 Bit, Version ≥ 18.09:
   Ensure you are running at least Windows 10 Professional or Windows 10 Enterprise in 64-bit mode and in Version 1809 (October 2018), 1903 (April 2019), 1909 (November 2019) or newer (including Windows 11).

   Rationale: Windows Subsystem for Linux (WSL) is available only under those Windows editions, only under 64-bit and in a reasonable fashion only under at least this version or newer. Windows 10 in Version 1809 is the bare minimum. The recommended system is at least Windows 10 in Version 1909 or newer (including Windows 11).

   • START → Settings → System → About:
   • ... Device Specifications → System type
   • ... Windows Specifications → Edition
   • ... Windows Specifications → Version

   Notice:

   If you have a different edition or you are running in 32-bit mode, you are out of luck with WSL. Sorry, then you have to went with MSYS2 or Cygwin. If you want to perform a fresh Windows 10/11 installation, start over with Microsoft's Download Windows 10 Disc Image (ISO File) or Download Windows 11 Disc Image (ISO File). If you just still have an older Windows version, upgrade with one of the following options:

   • Windows Updates: START → windows update settings RETURN
   • Windows Upgrades: Windows 10 Update Assistant
   • Windows Upgrades: Windows 11 Update Assistant

2. Enable Windows Subsystem for Linux:
   Enable the Windows feature Windows Subsystem for Linux. A reboot might be necessary.

   Rationale: Windows Subsystem for Linux is the core feature we want to use.

   • START → powershell → RIGHT-CLICK → Run as administrator
   • Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux

   Alternatively:

   • START → cmd → RIGHT-CLICK → Run as administrator
   • dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart

   Alternatively:

   • START → control panel → Programs → Programs and Features → Turn Windows features on or off → Windows-Subsystem for Linux

   Notice: In case you have trouble to enable Windows Subsystem for Linux, this can have many reasons. In most cases, the reason is that point (1) above is not exactly fulfilled. Start over there again.

3. Enable "Virtual Machine Platform" Feature
   Enable the Windows feature Virtual Machine Platform (required for WSL2). A reboot might be necessary.

   Rationale: WSL2 is recommended.

   • START → powershell → RIGHT-CLICK → Run as administrator
   • Enable-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform

   Alternatively:

   • START → cmd → RIGHT-CLICK → Run as administrator
   • dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart

   Alternatively:

   • START → control panel → Programs → Programs and Features → Turn Windows features on or off → Virtual Machine Platform

4. Install/Update WSL2 Linux Kernel
   Update the WSL2 Linux kernel.

   Rationale: WSL2 Linux kernel has to be up-to-date or WSL2 will complain.

   • Visit the Microsoft WSL2 Information Page and download and run the MSI installer for the WSL 2 Linux Kernel.

5. Enable Hardware Virtualization
   Enable the CPU Hardware Virtualization in the PC BIOS (required for WSL2).

   • Reboot your system
   • Hold "DELETE" key during boot.
   • Enable CPU Hardware Virtualization (VT-x/VMX).

6. Update WSL:
   Update to the latest version of Windows Subsystem for Linux.

   • START → powershell → RIGHT-CLICK → Run as administrator
   • wsl.exe --update

Install Ubuntu GNU/Linux Operating System

1. Install Ubuntu 22.04 LTS:
   Install Ubuntu GNU/Linux 22.04 Long Term Support (LTS) from the Microsoft Store.

   Rationale: you need a reasonable GNU/Linux distribution and it should receive updates for a longer time.

   • START → microsoft store → Search → ubuntu 22.04 lts → Install

   Notice: In case the Microsoft Store is not available on your system, the reason can be that you still have User Account Control (UAC) disabled, or you are still not signed in with a Microsoft Account (although it should be not required), or your Windows is still not activated or you are still running an evaluation version of Windows. Anyway, try to fix the problems the following way:

   • START → Settings → Updates & Security → Troubleshoot → Windows Store Apps → Run the troubleshooter

Setup Ubuntu GNU/Linux Operating System

1. Enter Ubuntu under WSL:
   Enter Ubuntu GNU/Linux under Windows Subsystem for Linux.

   Rationale: we have to setup Ubuntu from itself.

   • START → Ubuntu 22.04

   Just be patient on first launch, it really takes time. Then, when asked for your username, enter the same as your Windows username. When asked for your password, enter either your Windows password or another one, but remember it (at least once until the step where we configure sudo(8) below)! For all other questions, keep the defaults.

2. Enable Convenient Root Access:
   Ensure no password is needed for subsequent root access.

   Rationale: just convenience only -- feel free to ignore if you want to enter your password over and over again.

   • sudo vi /etc/sudoers
     ← %sudo ALL=(ALL:ALL) ALL
     → %sudo ALL=(ALL:ALL) NOPASSWD: ALL

3. Upgrade Ubuntu Operating System:
   Upgrade to the latest package versions of Ubuntu and allow APT to use HTTPS.

   Rationale: you always want the latest updates and Docker later needs HTTPS access.

   • sudo apt update -y &&
sudo apt upgrade -y --with-new-pkgs &&
sudo apt install -y apt-transport-https ca-certificates curl gnupg-agent software-properties-common

4. Mount Windows directories in WSL with Meta-Data enabled:
   Configure the mounting of Windows directories in WSL (/c instead of /mnt/c) and with Meta-Data enabled.

   Rationale: allow POSIX file permissions on Windows drives from within WSL.

   • sudo vi /etc/wsl.conf
     → [boot]
     → systemd = true
     → [automount]
     → enabled = true
     → root = /
     → options = "metadata,umask=022"

5. Use Combined Home Directory:
   Map the Unix home directory to the regular Windows home directory.

   Rationale: just convenience only -- feel free to ignore.

   • exec sudo usermod -d /c/Users/$USER $USER

   Notice: Don't panic, we have to exec the command here to release the current user's processes and this way let usermod proceed. This will immediately close the Unix terminal, of course. This step actually is a tricky one as the running WSL sub-process might not allow the changing of the underlying user home directory as long as it is running itself. One safe alternative is to execute the following command from within a CMD or PowerShell terminal:
   wsl sudo usermod -d /c/Users/%USERNAME% %USERNAME%

6. Activate Filesystem Layout:
   Perform a logout/login cycle on the host system to activate the new filesystem layout (mapping of /c and home directory)

   Rationale: WSL does not re-mount the filesystem without a logout/login or reboot

Configure Unix Shell Environment

1. Re-Enter Ubuntu under WSL:
   Re-Enter Ubuntu GNU/Linux under Windows Subsystem for Linux again.

   Rationale: we have to configure the Unix environment from itself.

   • START → Ubuntu 22.04

2. Install Essential Unix Tools:
   Install all necessary essential and some more useful Unix tools.

   Rationale: the subsequent Unix Shell Configurations are partially based on them and you really want a decent Unix environment.

   First, install the tools which available via standard package manager:

   • sudo apt install -y bash less vim vifm tmux &&
sudo apt install -y procps lsof dnsutils tcpdump &&
sudo apt install -y openssh-client stunnel subversion git curl &&
sudo apt install -y mc tree file findutils &&
sudo apt install -y rsync rdup rclone restic w3m lftp &&
sudo apt install -y atool gzip bzip2 xz-utils zip unzip &&
sudo apt install -y diffutils diffstat patch patchutils par &&
sudo apt install -y openssl gnupg golang-cfssl apg uuid bc &&
sudo apt install -y imagemagick ghostscript poppler-utils &&
sudo apt install -y gcc g++ bison flex

   Second, install the tool FZF which is not available (at least not in latest version) via standard package manager:

   • curl -skLO https://github.com/junegunn/fzf/releases/download/0.42.0/fzf-0.42.0-linux_amd64.tar.gz &&
tar zxf fzf-*-linux_amd64.tar.gz &&
sudo install -c -m 755 fzf /usr/local/bin/ &&
rm fzf fzf-*-linux_amd64.tar.gz

3. Optionally Install Additional Unix Tools:
   Install additionally useful Unix tools.

   Rationale: Git-Town and TTY2Web are often useful.

   • curl -skLO https://github.com/Originate/git-town/releases/download/v9.0.0/git-town_9.0.0_linux_intel_64.deb &&
sudo dpkg -i git-town_*.deb &&
rm git-town_*.deb &&
curl -skLO https://github.com/kost/tty2web/releases/download/v3.0.0/tty2web_linux_amd64 &&
sudo install -c -m 755 tty2web* /usr/local/bin/tty2web &&
rm tty2web*

4. Install Unix Shell Configurations:
   Install Dr. Ralf S. Engelschall's essential Unix dotfiles.

   Rationale: you really want a reasonable pre-configured Unix shell environment.

   • sudo apt install -y make &&
curl -skLO https://github.com/rse/dotfiles/archive/master.zip &&
unzip -x master.zip &&
(cd dotfiles-master && sudo make install) &&
rm -rf dotfiles-master &&
rm master.zip &&
dotfiles -f ~

5. Install UTF-8 locale information:
   Install the UTF-8 locale information into the system.

   Rationale: prevent Bash from complaining afterwards.

   • sudo localedef -i en_US -f UTF-8 en_US.UTF-8

6. Install Unix Shell Addon Configurations:
   Install Dr. Ralf S. Engelschall's Bash-FZF and Bash-ENVRC addons.

   Rationale: you really want a reasonable pre-configured Unix shell environment. This especially includes an improved CTRL+r functionality in Bash, which then opens an FZF-based search functionality (which you can see in the screenshot above, too).

   • curl -skL https://raw.githubusercontent.com/rse/bash-fzf/master/bash-fzf.rc -o ~/.bash-fzf.rc &&
curl -skL https://raw.githubusercontent.com/rse/bash-envrc/master/bash-envrc.rc -o ~/.bash-envrc.rc &&
exec bash
     

   • cdpaths -g

7. Optionally Extend Unix Shell Configurations:
   Extend the Unix shell configuration with your personal information.

   Rationale: these informations individualize your environment (replace the <xxx> placeholders, please).

   • vi ~/.dotfiles/gitconfig
     → [user]
     → user = <username>
     → name = <firstname> <lastname>
     → email = <firstname>.<lastname>@<domain>
     

8. Install WSL Utilities:
   Install additional WSL utilities.

   Rationale: you want additional features inside WSL.

   • sudo apt install -y ubuntu-wsl wslu &&
curl -skLO https://github.com/4U6U57/wsl-open/archive/master.zip &&
unzip -x master.zip &&
sudo install -c -m 755 wsl-open-master/wsl-open.sh /usr/local/bin/wsl-open &&
sudo mkdir -p /usr/local/share/man/man1 &&
sudo install -c -m 644 wsl-open-master/wsl-open.1 /usr/local/share/man/man1/ &&
rm -rf wsl-open-master &&
rm master.zip

   • curl -skLO https://github.com/CzBiX/WSLHostPatcher/releases/download/v0.1.2/WSLHostPatcher.zip &&
unzip -x WSLHostPatcher.zip &&
mkdir -p ~/AppData/Local/WSLHostPatcher &&
chmod 755 WSLHostPatcher.exe &&
mv WSLHostPatch.dll WSLHostPatcher.exe ~/AppData/Local/WSLHostPatcher/ &&
rm -f WSLHostPatcher.zip WSLHostPatch*.*

   • vi ~/.dotfiles/bashrc
     → PATH=$PATH:/c/Windows/System32/WindowsPowerShell/v1.0/
     → alias wsl="/c/Windows/System32/wsl.exe"
     → alias cmd="/c/Windows/System32/cmd.exe"
     → alias wsl-host-patcher="$HOME/AppData/Local/WSLHostPatcher/WSLHostPatcher.exe"
     → alias open=wsl-open

9. Optionally avoid system messages:
   Force the system to not display messages.

   Rationale: you don't want to be nerved with those messages

   • touch ~/.hushlogin

Install MinTTY/WSLTTY Terminal Emulator

1. Install MinTTY/WSLTTY:
   Install the WSLTTY variant of MinTTY.

   Rationale: a reasonable terminal emulator has to be used and the default WSL console is not good enough.

   • WSLTTY version ≥ 3.6.4 → wsltty-*-install.exe
   • WIN+r → %LOCALAPPDATA%\wsltty → add to context menu.lnk

2. Install DejaVu Sans Mono font:
   Install a perfect monospaced font for the terminal emulator.

   Rationale: MinTTY/WSLTTY configuration below references it.

   • download: DejaVu Sans ≥ 2.37 → dejavu-fonts-ttf-*.zip
   • extract: dejavu-fonts-ttf-*.zip → RIGHT-CLICK Extract all
   • install: dejavu-fonts-ttf-*\ttf\ → select all *.ttf → RIGHT-CLICK → Install

3. Install MinTTY/WSLTTY Configuration:
   Install Dr. Ralf S. Engelschall's MinTTY/WSLTTY configuration.

   Rationale: reasonable colors and fonts should be used in the terminal emulator.

   • download: MinTTY-config
   • extract: master.zip → RIGHT-CLICK Extract all
   • copy: mintty-config-master\config
   • paste: %APPDATA%\wsltty (override config file)

4. Optionally Make MinTTY/WSLTTY easily accessible:
   Pin MinTTY/WSLTTY to the Windows taskbar and additionally assign it to the global Windows hotkey CTRL+ALT+c.

   Rationale: easy and quick access to the Unix shell

   • START → wsl terminal → RIGHT-CLICK Pin to taskbar.
   • Taskbar → WSL Terminal → RIGHT-CLICK → WSL Terminal →
     
   • ...RIGHT-CLICK → Properties → Shortcut key → CTRL+ALT+c.

---

Optionally Install Secure-Shell (SSH) Environment (feel free to skip)

1. Install PuTTY:
   Install the PuTTY SSH client.

   Rationale: you want to run the PuTTY Agent (pageant) for reasonable SSH agent support.

   • PuTTY Downloads → putty-64bit-*-installer.msi

2. Generate SSH Key:
   Generate (or use existing) SSH key.

   Rationale: you don't want to use passwords, of course.

   • START → puttygen RETURN
   • → Generate
   • → Key passphrase & Confirm passphrase
   • → Save public key → c:\Users\<username>\Documents\ssh-key-pub.pem
   • → Save private key → c:\Users\<username>\Documents\ssh-key-prv.ppk
   • → Conversions → Export OpenSSH key → c:\Users\<username>\Documents\ssh-key-prv.pem.
     

3. Autostart PuTTY Agent:
   Enable the PuTTY Agent to autostart on login and load the SSH private key.

   Rationale: you want it to be running all the time.

   • WIN+e → %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup → RIGHT-CLICK → New → Shortcut
   • "C:\Program Files\PuTTY\pageant.exe" "C:\Users\<username>\Documents\ssh-key-prv.ppk"

4. Install PuTTY Agent Client (Weasel-Pageant)
   Install Weasel-Pageant for accessing the PuTTY Agent from within WSL.

   Rationale: you want to directly access PuTTY Agent from within WSL.

   • Weasel-Pageant Downloads → weasel-pageant-1.4.zip
   • weasel-pageant-1.4.zip → RIGHT-CLICK → Extract all
   • move weasel-pageant-1.4\ to %APPDATA%\weasel-pageant\

5. Enter Ubuntu under WSL via MinTTY/WSLTTY:
   Re-Enter Ubuntu GNU/Linux under Windows Subsystem for Linux again (this time via MinTTY/WSLTTY).

   Rationale: we have to configure also the Unix version of SSH.

   • START → wsl terminal RETURN

6. Configure Unix Environment for SSH Agent:
   Configure the Unix environment to use the Weasel-Pageant as the SSH agent.

   Rationale: in every WSL terminal you want SSH agent access available automatically.

   • vi ~/.dotfiles/bashrc
     → eval $(~/AppData/Roaming/weasel-pageant/weasel-pageant -r -s)

Optionally Enable Windows Subsystem for Linux (WSL) Version 2 (Windows 10/11 Version >= 19.03 only) (feel free to skip)

2. Switch to use WSL 2

   • START → cmd
   • wsl --set-default-version 2
   • wsl --set-version Ubuntu-22.04 2

Optionally Install Podman/Docker/Docker-Compose/Kubectl/Minikube/Helm Client CLIs (feel free to skip)

1. Re-Enter Ubuntu under WSL:
   Re-Enter Ubuntu GNU/Linux under Windows Subsystem for Linux again.

   Rationale: we have to operate inside Ubuntu here again.

   • START → wsl terminal RETURN

2. Install Podman/Skopeo/Buildah:
   Install Podman, the daemon-less Docker alternative, and its companion tools Skopeo (registry access) and Buildah (container build).

   Rationale: Podman is a Docker-compatible daemon-less way to run containers. Notice that In WSL there are no systemd(8) and journald(8) daemons running, so the environment has to be slightly adjusted to allow podman to work correctly.

   • (. /etc/os-release; echo "deb https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/testing/xUbuntu_${VERSION_ID}/ /" | sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:testing.list; curl -skL "https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/testing/xUbuntu_${VERSION_ID}/Release.key" | sudo apt-key add - ) && sudo apt update -y; sudo apt install -y podman skopeo buildah

   • sed -e 's;^# cgroup_manager = .*;cgroup_manager = "cgroupfs";' -e 's;^# events_logger = .*;events_logger = "file";' </usr/share/containers/containers.conf >/tmp/container.conf; sudo install -c -m 644 /tmp/containers.conf /etc/containers/containers.conf; rm /tmp/containers.conf

3. Install Docker/Docker-Compose:
   Install original native Linux version of the Docker and Docker-Compose CLIs.

   Rationale: the original native Linux versions works more flawless than executing the Windows versions under WSL.

   • curl -skL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - && sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" && sudo apt update -y && sudo apt install -y docker-ce docker-ce-cli

   • V=$(curl -skL https://github.com/docker/compose/releases | egrep 'releases/tag/v[0-9.]*"' | sed -e 's;^.*releases/tag/v;;' -e 's;".*$;;' | head -1); sudo curl -skL https://github.com/docker/compose/releases/download/v${V}/docker-compose-linux-x86_64 -o /usr/libexec/docker/cli-plugins/docker-compose; sudo chmod 755 /usr/libexec/docker/cli-plugins/docker-compose

4. Install Kubectl/Minikube/Helm:
   Install the Kubernetes client kubectl(1), the Kubernetes all-in-one server minikube(8) and the Kubernetes package manager helm(1).

   Rationale: when dealing with the Kubernetes world of containers, those two CLIs are essential.

   • sudo curl -skL https://storage.googleapis.com/kubernetes-release/release/$(curl -skL https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl && sudo chmod 755 /usr/local/bin/kubectl

   • sudo curl -skL https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 -o /usr/local/bin/minikube; sudo chmod 755 /usr/local/bin/minikube

   • V=$(curl -skL https://github.com/kubernetes/helm/releases | egrep 'releases/tag/v3\.[0-9.]*"' | sed -e 's;^.*releases/tag/v;;' -e 's;".*$;;' | head -1); curl -skL $(printf "%s%s" https://get.helm.sh/helm-v${V}-linux-amd64.tar.gz) | sudo tar -z -x -f - --strip-components=1 -C /usr/local/bin linux-amd64/helm; sudo chmod 755 /usr/local/bin/helm

Optionally Establish DockerD/ContainerD as Container Runtime (Alternative 1, WSL2 only) (feel free to skip)

Pro: the original and no root permissions required for docker(1) and docker-compose(1) calls
Con: intransparent and slowed down development

1. Allow Access to Daemon
   Allow the current user access to the Docker daemon.

   • sudo usermod -aG docker $USER

2. Configure User Environment:
   Configure the user environment to auto-start the Docker daemon.

   Rationale: WSL has no init scripts, so start the Docker daemon manually when the shell is opened.

   • vi ~/.dotfiles/bashrc
     → (sudo service docker start || true) >/dev/null 2>&1

Optionally Establish Podman as Container Runtime (Alternative 2, WSL2 only) (feel free to skip)

Pro: fully transparent and fast Open Source development
Con: the clone and root permissions required for docker(1) and docker-compose(1) calls

1. Provide Docker REST API Service:
   Let Podman provide the Docker REST API as a Unix domain socket under the usual /var/run/docker.sock path.

   Rationale: Docker-Compose requires this access method.

   • curl -L "https://fdit-gitlab.dit.htwk-leipzig.de/martin.meszaros/wsl2-podman-compose/-/raw/master/podman-service?inline=false" >podman-service; install -c -m 755 podman-service /etc/init.d/; rm podman-service

2. Configure User Environment:
   Configure the user environment to auto-start the Docker REST API of Podman.

   Rationale: WSL has no init scripts, so start the Podman socket service manually when the shell is opened.

   • vi ~/.dotfiles/bashrc
     → (sudo service podman-service start || true) >/dev/null 2>&1

3. Substitute Docker CLI
   Substitute the call-compatible podman(1) for docker(1).

   • sudo apt remove docker-ce docker-ce-cli
   • sudo sh -c '(echo "#!/bin/sh"; echo "exec /usr/bin/podman \"\$@\"") >/usr/local/bin/docker && chmod 755 /usr/local/bin/docker'

Optionally Establish Docker for Windows as Container Runtime (Alternative 3, Host only) (feel free to skip)

Pro: Docker available also on the host, Kubernetes included
Con: intransparent and slowed down development, no longer free for large Enterprise use

1. Install Docker Desktop:
   Install the Docker Desktop for Windows (Community Edition) distribution.

   Rationale: you want Docker container engine be available on the host.

   • START → control panel → Programs → Programs and Features → Turn Windows features on or off → Hyper-V (a reboot is required)

   • Docker Desktop → Download for Windows (a reboot is required)

   • START → computer management RIGHT-CLICK → Run as administrator

   • Computer Management → System Tools → Local Users and Groups → Groups → docker-users → LEFT-DOUBLE-CLICK → Add... (ensure that your user is really in this group -- usually it is the case by default)

   Notice: You need a Docker Hub account for downloading and using Docker Desktop. Sign up first if you still don't have a Docker Hub account.

   Notice: Yes, Hyper-V is necessary as Docker Desktop for Windows (in contrast to the regular Docker for Linux) runs Docker inside a small Linux distribution which is executed in a virtual machine via Hyper-V.

2. Start & Configure Docker Desktop:
   Start and configure Docker Desktop.

   Rationale: for CLI access from within WSL 1, the Docker daemon API has to be exposed via TCP on localhost. For WSL 2 Docker for Windows has a special type of integration which does not need this any longer.

   • START → docker desktop RETURN
   • System Tray → Docker Desktop → RIGHT-CLICK → Settings → General → Expose daemon...

3. Re-Enter Ubuntu under WSL:
   Re-Enter Ubuntu GNU/Linux under Windows Subsystem for Linux again.

   Rationale: we have to install also the Unix client side of Docker.

   • START → wsl terminal RETURN

4. Configure User Environment:
   Configure the user environment to access Docker for Windows on the host.

   Rationale: the access works through the TCP socket instead of the usual Unix domain socket.

   • vi ~/.dotfiles/bashrc
     → export DOCKER_HOST=tcp://localhost:2375

Optionally install Language Runtimes (feel free to skip)

1. Install Node.js:
   Install the Node.js JavaScript language runtime.

   Rationale: you want a reasonable JavaScript environment available.

   • curl -sL https://deb.nodesource.com/setup_20.x | sudo -E bash -
   • sudo apt install -y nodejs

2. Install OpenJDK:
   Install the OpenJDK Java language runtime.

   Rationale: you want a reasonable Java environment available.

   • sudo apt install -y default-jdk