All changes here are specific to ubuntu 20.04

wsl2-hacks

Useful snippets / tools for using WSL2 as a development environment

Auto-start/services (systemd and snap support)

I've done a few methods that have had various levels of success. My goal was to make it feel seamless for my workflow and have commands work as expected. What's below is the current version of the setup I use. It allows me to use the MS Terminal as well as VSCode's Remote WSL plugin.

With this setup your shells will be able to run systemctl commands, have auto-starting services, as well as be able to run snaps.

Install deps

$ sudo apt update
$ sudo apt install dbus policykit-1 daemonize

Exit out of / close the WSL2 shell

The next step is to shutdown WSL2 and to change the default user to root.

In a PowerShell terminal run:
```
> wsl --shutdown
> ubuntu2004.exe config --default-user root
```

Create a fake-bash

This fake shell will intercept calls to wsl.exe bash ... and forward them to a real bash running in the right environment for systemd. If this sounds like a hack-- well, it is. However, I've tested various workflows and use this daily. That being said, your mileage may vary.

$ touch /usr/bin/bash-bootstrap-services
$ chmod +x /usr/bin/bash-bootstrap-services
$ code /usr/bin/bash-bootstrap-services

Code can be replaced with your editor of choice

Add the following, be sure to replace <YOURUSER> with your WSL2 Linux username

#!/bin/bash
# your WSL2 username
UNAME="<YOURUSER>"

UUID=$(id -u "${UNAME}")
UGID=$(id -g "${UNAME}")
UHOME=$(getent passwd "${UNAME}" | cut -d: -f6)
USHELL=$(getent passwd "${UNAME}" | cut -d: -f7)

if [[ -p /dev/stdin || "${BASH_ARGC}" > 0 && "${BASH_ARGV[1]}" != "-c" ]]; then
    USHELL=/bin/bash
fi

if [[ "${PWD}" = "/root" ]]; then
    cd "${UHOME}"
fi

# get pid of systemd
SYSTEMD_PID=$(pgrep -xo systemd)

# if we're already in the systemd environment
if [[ "${SYSTEMD_PID}" -eq "1" ]]; then
    exec "${USHELL}" "$@"
fi

# start systemd if not started
/usr/bin/daemonize -l "${HOME}/.systemd.lock" /usr/bin/unshare -fp --mount-proc /lib/systemd/systemd --system-unit=basic.target 2>/dev/null
# wait for systemd to start
while [[ "${SYSTEMD_PID}" = "" ]]; do
    sleep 0.05
    SYSTEMD_PID=$(pgrep -xo systemd)
done

# enter systemd namespace
exec /usr/bin/nsenter -t "${SYSTEMD_PID}" -m -p --wd="${PWD}" /sbin/runuser -s "${USHELL}" "${UNAME}" -- "${@}"

Test the Script

In a PowerShell terminal run:
```
> wsl --shutdown
```
Fire up WSL via the MS Terminal or just wsl.exe. Start ubunutu and test the script you created by running
```
$  bash /usr/bin/bash-bootstrap-services
```
If You are logged in as your normal user then the script is working good and systemd should be running

You can test by running the following in WSL2:
```
$ systemctl is-active dbus
active
```
Set the fake-bash as our root user's shell

We need root level permission to get systemd setup and enter the environment. The way I went about solving this is to have WSL2 default to the root user and when wsl.exe is executed the fake-bash will do the right thing.

The next step in getting this working is to change the default shell for our root user.

Edit the /etc/passwd file:

$ sudo editor /etc/passwd

Find the line starting with root:, it should be the first line. Change it to:

root:x:0:0:root:/root:/usr/bin/bash-bootstrap-services

Note the /usr/bin/bash-bootstrap-services here, slight difference

Save and close this file. Close the WSL and start again. Eveything should be working fine.
Create /etc/rc.local (optional)

If you want to run certain commands when the WSL2 VM starts up, this is a useful file that's automatically ran by systemd.
```
$ sudo touch /etc/rc.local
$ sudo chmod +x /etc/rc.local
$ sudo editor /etc/rc.local
```
Add the following:
```
#!/bin/sh -e

# your commands here...

exit 0
```

/etc/rc.local is only run on "boot", so only when you first access WSL2 (or it's shutdown due to inactivity/no-processes). To test you can shutdown WSL via PowerShell/CMD wsl --shutdown then start it back up with wsl.

Increase max_user_watches

If devtools are watching for file changes, the default is too low.

# /etc/rc.local runs as root by default
# if you run these yourself add 'sudo' to the beginning of each command

sysctl -w fs.inotify.max_user_watches=524288

Open MS Terminal to home directory by default

Open your MS Terminal configuration Ctrl+,

Find the "commandLine":... config for the WSL profile.

Change to something like:

"commandline": "wsl.exe ~ -d Ubuntu-18.04",

Get current IP of WSL2 into Windows clipboard :

Create a file called getip with the following command sh $ sudo touch /usr/local/bin/getip $ sudo cjmod +x /usr/local/bin/getip Put the following code inside the getip file using your editor

hostname -I | awk '{print $1}' | awk '{printf "%s", $0}' | clip.exe
hostname -I | awk '{print $1}' | awk '{printf "%s", $0}' 
echo

Now everytime you type getip you will be shown the IP and it will be copied into the clipboard.

Run sudo code command for files with Previliges

Currently you cannot run sudo code command. Using defualt user as root is not recommended. So best approach is to use rmate.

Install rmate on your WSL VM sudo wget -O /usr/bin/rmate https://raw.githubusercontent.com/aurora/rmate/master/rmate sudo chmod a+x /usr/bin/rmate
Install the Remote VS Code plugin make sure the Extension is enabled on WSL: after adding the plugin. Here is how I configured the remote VS Code plugin File -> Preferences -> Settings
Start the VSCode rmate server Press F1 and run Search for the Remote: Start Server command.
Edit your privileged files Start your WSL instance and open a terminal. If you've done everything correctly you should be able to now edit your files with sudo priveledges in your editor, even if you are not the root user.

sudo rmate /etc/profile.d/custom-profile.sh

Make it possible to run sudo code to change root files from wsl2

Currently sudo code doesnt work from wsl2. To make sudo code run you need to modify to configuration file /etc/sudoers. Please open the file and modify the secure_path to enable run VS code with sudo command as below Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin:/mnt/c/Program Files/Vscodium/bin" Just add the path to the bin folder of the VS code installation. Please note I use VScodium instead of VS Code so slight difference.

chcoders/wsl2-hacks-ubunutu2004

All changes here are specific to ubuntu 20.04

wsl2-hacks