Boot failure of functional tests with Debian-derivatives

[dongsupark]

Description

While #108 made it already possible to specify --groups or env variable AZURE_INIT_USER_GROUPS, functional tests still fail when testing Debian-derivatives like Ubuntu, because the distros do not have the default group wheel.

azure-init: useradd: group `wheel` does not exist
Failed to start Azure-init
azure-init: Failed to create a user; none of the provided backends succeeded

[anhvoms]

We should not assume there's a group wheel. It's better to write to /etc/sudoers to give the created user sudo privilege instead of assuming any group's existence

[dongsupark]

We should not assume there's a group wheel. It's better to write to /etc/sudoers to give the created user sudo privilege instead of assuming any group's existence

That is what add_user_for_passwordless_sudo is already doing. See this.
libazureinit seems to already do the right thing. It is rather an integration issue with functional tests.

I pushed a WIP commit, which makes functional tests pass again with Debian/Ubuntu. But of course that is not enough.

[anhvoms]

The code by default will always add group wheel: here

[dongsupark]

Ok, will work on the issue in 2 steps: a hotfix for removing wheel by default, and afterwards more functional tests for multiple distros.