Automatic setup with cloud-init¶

Authored by Carlos Nihelton (carlos.santanadeoliveira@canonical.com)

Cloud-init is an industry-standard multi-distribution method for cross-platform cloud instance initialisation. Ubuntu WSL users can now leverage it to perform an automatic setup to get a working instance with minimal touch.

See more: cloud-init official documentation.

Note

*Coming soon:

That feature is currently in development and will be available soon on the UbuntuPreview app first, then gradually released for the latest LTS applications.

What you will learn:¶

How to write cloud-config user data to a specific WSL instance.
How to automatically set up a WSL instance with cloud-init.
How to verify that cloud-init succeeded with the configuration supplied.

What you will need:¶

Windows 11 with WSL 2 already enabled
The latest UbuntuPreview application from Microsoft Store.

Write the cloud-config file¶

Locate your Windows user home directory. It typically is C:\Users\<YOUR_USER_NAME>.

You can be sure about that path by running echo $env:USERPROFILE in PowerShell.

Inside your Windows user home directory, create a new folder named .cloud-init (notice the . à la Linux configuration directories), and inside the new directory, create an empty file named Ubuntu-Preview.user-data. That file name must match the name of the distro instance that will be created in the next step.

Open that file with your text editor of choice (notepad.exe is just fine) and paste in the following contents:

#cloud-config
locale: pt_BR
users:
- name: jdoe
  gecos: John Doe
  groups: [adm,dialout,cdrom,floppy,sudo,audio,dip,video,plugdev,netdev]
  sudo: ALL=(ALL) NOPASSWD:ALL
  shell: /bin/bash

write_files:
- path: /etc/wsl.conf
  append: true
  content: |
    [user]
    default=jdoe

packages: [ginac-tools, octave]

runcmd:
   - git clone https://github.com/Microsoft/vcpkg.git /opt/vcpkg
   - /opt/vcpkg/bootstrap-vcpkg.sh

Save it and close it.

That example will create a user named jdoe and set it as default via /etc/wsl.conf, install the packages ginac-tools and octave and install vcpkg from the git repository, since there is no deb or snap of that application (hence the reason for being included in this tutorial - it requires an unusual setup).

See more: WSL data source reference.

Register a new Ubuntu-Preview instance¶

In PowerShell, run:

ubuntupreview.exe install --root

We skip the user creation since we expect cloud-init to do it.

If you want to be sure that there is now an Ubuntu-Preview instance, run wsl -l -v. Notice that the application is named UbuntuPreview but the WSL instance created is named Ubuntu-Preview. See more about that naming convention in our reference documentation.

Check that cloud-init is running¶

In PowerShell again run:

ubuntupreview run cloud-init status --wait

That will wait until cloud-init completes configuring the new instance we just created. When done, you should see an output similar to the following:

..............................................................................
..............................................................................
..............................................................................
...................
status: done

Verify that it worked¶

Restart the distro just to make sure the changes in /etc/wsl.conf made by cloud-init will take effect, as listed below:

> wsl -t Ubuntu-Preview
The operation completed successfully.
> ubuntupreview
To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.

Welcome to Ubuntu Noble Numbat (development branch) (GNU/Linux 5.15.137.3-microsoft-standard-WSL2 x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro


This message is shown once a day. To disable it please create the
/home/cn/.hushlogin file.
jdoe@mib:~$

Once logged in the new distro instance’s shell, verify that:

The default user matches what was configured in the user data file (in our case jdoe).

jdoe@mib:~$ whoami
jdoe

The supplied cloud-config user data was approved by cloud-init validation.

jdoe@mib:~$ sudo cloud-init schema --system
Valid schema user-data

The locale is set

jdoe@mib:~$ locale
LANG=pt_BR
LANGUAGE=
LC_CTYPE="pt_BR"
LC_NUMERIC="pt_BR"
LC_TIME="pt_BR"
LC_COLLATE="pt_BR"
LC_MONETARY="pt_BR"
LC_MESSAGES="pt_BR"
LC_PAPER="pt_BR"
LC_NAME="pt_BR"
LC_ADDRESS="pt_BR"
LC_TELEPHONE="pt_BR"
LC_MEASUREMENT="pt_BR"
LC_IDENTIFICATION="pt_BR"
LC_ALL=

The packages were installed and the commands they provide are available

jdoe@mib:~$ apt list --installed | egrep 'ginac|octave'

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

ginac-tools/noble,now 1.8.7-1 amd64 [installed]
libginac11/noble,now 1.8.7-1 amd64 [installed,automatic]
octave-common/noble,now 8.4.0-1 all [installed,automatic]
octave-doc/noble,now 8.4.0-1 all [installed,automatic]
octave/noble,now 8.4.0-1 amd64 [installed]

Verify that the commands requested were also run. In this case we set up vcpkg from git, as recommended by its documentation (there is no deb or snap available for that program).

jdoe@mib:~$ /opt/vcpkg/vcpkg version
vcpkg package management program version 2024-01-11-710a3116bbd615864eef5f9010af178034cb9b44

See LICENSE.txt for license information.

Enjoy!¶

That’s all folks! In this tutorial, we’ve shown you how to use cloud-init to automatically set up Ubuntu on WSL 2 with minimal touch.

This workflow will guarantee a solid foundation for your next Ubuntu WSL project.

We hope you enjoy using Ubuntu inside WSL!