systemd needs this so special characters (like the ones in wireguard
units that appear because they are part of base64) can be escaped using
the \x syntax.
Root of the issue is that `glob()` handles the backslash internally
which is obviously not what we want here.
Also add a test case and fix some perlcritic issues in the subroutine.
There are now multiple combinations of how one can pass either
extraPackages or extraComponents. We now test those passed directly to
the package via an override, and those passed indirectly via the module,
that ultimately results in a second override to the package.
The test failed with
> Test "test5 user should not be able to run commands under root" failed with
> error: "invalid literal for int() with base 10: ''"
since 2492da88ea.
The reason for this is that `sudo(8)` writes the lecture to the
tty[1] and only as a fallback to stdout[2]. This means that the
`base64 --wrap 0` executed by `machine.execute()` doesn't affect the
text written to the terminal, however the lecture is part of the string
that's read from the VM via `shell.recv()`.
I confirmed the problem in an interactive test session[3]:
>>> command = "sudo -u test5 sudo -n -u root true"
>>> out_command = f"( set -euo pipefail; {command} ) | (base64 --wrap 0; echo)\n"
>>> machine.shell.send(out_command.encode())
84
>>> machine # [ 99.015512] sudo[877]: root : TTY=hvc0 ; PWD=/tmp ; USER=test5 ; COMMAND=/run/wrappers/bin/sudo -n -u root true
machine # [ 99.019373] sudo[877]: pam_unix(sudo:session): session opened for user test5(uid=1005) by (uid=0)
machine # [ 99.038692] sudo[879]: pam_unix(sudo:auth): conversation failed
machine # sudo: a password is required
machine # [ 99.041860] sudo[879]: pam_unix(sudo:auth): auth could not identify password for [test5]
machine # [ 99.046901] sudo[877]: pam_unix(sudo:session): session closed for user test5
>>>
>>> x=machine._next_newline_closed_block_from_shell()
>>> print(x)
<newline>
We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:
<newline>
#1) Respect the privacy of others.
#2) Think before you type.
#3) With great power comes great responsibility.
<newline>
<newline>
<newline>
>>>
Since the lecture isn't strictly necessary to confirm that
`security.sudo` works as expected, I decided to disable lecturing
inside the test, however we may want to fix the underlying problem in
the test-driver at some point.
[1] https://github.com/sudo-project/sudo/blob/SUDO_1_9_9/plugins/sudoers/check.c#L275-L283
[2] https://github.com/sudo-project/sudo/blob/SUDO_1_9_9/src/conversation.c#L95-L120
[3] I replaced each empty line with `<newline>` to make sure these
aren't swallowed by git.
