WSL2 Create environment variable for all users

Question

I am using Ubuntu as my preferred Linux distro for WSL2. I want to create an environment variable that persist across all users.

I already tried lots of answers and none of them work. They work on a virtual machine but they do not work under WSL. For example I already tried every answer from this question https://askubuntu.com/questions/161924/how-do-i-set-persistent-environment-variables-for-root. My goal is to run from command prompt wsl echo $FOO and it work just like wsl echo $USER works..

Also wsl default user needs to be root.

Anyways here are the steps I am doing based on all the answers and research.

1. Enable root user and every time I run ubuntu start it as root user

# First enable root user on Ubuntu by running this on ubuntu wsl:
sudo passwd root
# enter password etc...

# Then set that user as the default user. On command prompt run:
Ubuntu config --default-user root

2. Place environment variable FOO under /etc/environment as:

FOO="TRUE"

3. Restart computer for changes to take effect

4. Open ubuntu and run echo $FOO. This displays nothing. If I switch the user to tono for example with su tono and then run the same command it works.

5. I did some research and I change the line from Defaults env_reset to Defaults !env_reset on /etc/sudoers so that variables are not reset. Making this change and rebooting computer still does not work.

6. I now modify file /root/.bashrc and add the environment variable in there. That works but only if I am inside the terminal. If from command prompt I run wsl echo $FOO it does not work.

In short my goal is to run the command wsl echo $FOO and for it to return true just like wsl echo $USER will work. Am I going to have to store the value of that variable in a file just because of how complicated it is to create a environment variable that persist for all users?

Edit

I am just going to create a folder /env with all environment variables in there. That way I will be able to run

wsl echo "hello $(cat /env/FOO) world"

Longer but it will work for sure

Answer 1

Okay there are two questions. For environment variables, you can use WSLENV.

For default user, I'm new to wsl too and don't know how to help you. But my suggestion is don't rely on root.

Here are the example to use WSLENV:

#!pwsh
> $env:FOO="asdf"
> $env:WSLENV="FOO"
> wsl echo `$FOO
asdf

In this example i'm not persisting environment. If you want to make it persistant, use setx.exe or google for a GUI based solution.

reference: WSLENV:https://devblogs.microsoft.com/commandline/share-environment-vars-between-wsl-and-windows/

Answer 2

I placed all my environment variables under /env/my-env-variables.sh as

var1="true"
export var1

var2="false"
export var2

alias my_alias="echo hello-world"

# ...etc

now on ~/.bashrc I append the line at the end: source /env/my-env-variables.sh so that they work when I am using the shell.

Now every time I execute a script from windows I just have to remember to include those variables as:

wsl source /env/my-env-variables.sh ; echo $var1