Bug#955733: cloud-init does not set locale specified in user data

[Noah Meyerhans <noahm@debian.org>]

On Sat, Apr 04, 2020 at 11:49:42AM +0100, Nick Holloway wrote:
> Package: cloud-init
> Version: 18.3-6

Confirmed that the behavior as described is still an issue in cloud-init
22.4.2-1 in bookworm.

> The command "locale-gen" does not accept a locale as an argument, but
> only generates the locales listed in "/etc/locale.gen".  So the locale
> requested does not get generated, and causes the subsequent failure when
> setting locale.
> 
>     2020-04-04 10:00:43,196 - util.py[DEBUG]: Running command ['update-locale', '--locale-file=/etc/default/locale', 'LANG=en_GB.UTF-8'] with allowed return codes [0] (shell=False, capture=False)
> 

I think that each of the components is working correct if viewed in
isolation, but the end result is not what you expect.  If we document
that you must first populate /etc/locale.gen with the desired list of
available locales, that may be sufficient.  For example, the following
sets the desired locale:

admin@ip-10-0-3-7:~$ sudo cat /var/lib/cloud/instance/user-data.txt
#cloud-config
write_files:
    - path: /etc/locale.gen
      content: ZW5fR0IuVVRGLTggVVRGLTgK
      encoding: base64
locale: en_GB.UTF-8
admin@ip-10-0-3-7:~$ echo "ZW5fR0IuVVRGLTggVVRGLTgK" | openssl base64 -d
en_GB.UTF-8 UTF-8

Do Ubuntu systems list all known locales in /etc/locale.gen?  That would
make the locale module work without additional configuration, but seems
unnecessarily expensive.

noah