Bug#977358: release-notes: document how to make the rescue mode usable if no root password is set (buster)

[Justin B Rye <justin.byam.rye@gmail.com>]

Andrei POPESCU wrote:
>> (Should there be some hint here at the fact that this has happened
>> because we've switched to an implementation of sulogin without the
>> slightly dodgy Debian-specific patches?)
> 
> This is explained in the bug report for who cares to investigate, in my 
> opinion it's not needed in the Release Notes.

This was mostly a note to myself in the hope that I'd find a way of
leading into it that accentuated the positive - after all, this is
just a side-effect of improvements elsewhere.  But when we're this
late documenting it, it's a non-starter.

[...]
>> This probably needs an external link, but I'm not optimistic we'll
>> find one.  Maybe this is another case where we'll need a dedicated
>> page on wiki.debian.org.
> 
> As you probably know, it's as simple as:
> 
>     systemctl edit rescue.service
> 
>     and add
> 
>     [Service]
>     Environment=SYSTEMD_SULOGIN_FORCE=1
> 

Well, I know that now, because I've been looking it up, but I wasn't
sure as I wrote that, and it's not as easy to pull the details
together as it should be.  Still, at least it doesn't need the usual
reminders to run daemon-reload or reboot.  But instead of telling
people all about where to hunt for the information it might be quicker
in this case just to put the answer in the text!

   <title>
     The <literal>rescue</literal> boot option is unusable without a root password
   </title>
   <para>
     Booting with the <literal>rescue</literal> option always requires
     the root password. If one has not been set, this makes the rescue
     mode effectively unusable. However it is still possible to boot
     using the kernel parameter <literal>init=/sbin/sulogin --force</literal>
   </para>
   <para>
     To configure systemd to do the equivalent of this whenever it boots
     into rescue mode (also known as single mode: see <ulink
     url="&url-man;/bullseye/systemd/systemd.1.html">systemd(1)</ulink>),
     run <command>sudo systemctl edit rescue.service</command> and create
     a file saying just:
   </para>
   <screen>
     [Service]
     Environment=SYSTEMD_SULOGIN_FORCE=1
   </screen>
   <para>
     It might also (or instead) be useful to do this for the
     <literal>emergency.service</literal> unit, which is started
     <emphasis>automatically</emphasis> in the case of certain
     errors (see <ulink
     url="&url-man;/bullseye/systemd/systemd.special.7.html">systemd.special(7)</ulink>),
     or if <literal>emergency</literal> is added to the kernel
     command line (e.g. if the system can't be recovered by using
     the rescue mode).
   </para>

[...]
>> (Why *did* setting these systems up with passwords in the first place
>> go out of fashion?)
> 
> For me it was a natural consequence of using sudo exclusively ;)

Ah, well, it's the old slogan - "Debian: giving you the power to shoot
yourself in each toe individually."

>>>     For background and a discussion on the security implications see 
>>>     bts:802211.
>> 
>> I forget if we've got special markup for this or whether we just say
> 
> All entities are in a dedicated file (I don't have a checkout handy to 
> look it up).

I can't see the definition, but judging by old .po files we want

    <para>
      For background and a discussion on the security implications see
      <ulink url="&url-bts;/802211">#802211</ulink>.
    </para>

-- 
JBR	with qualifications in linguistics, experience as a Debian
	sysadmin, and probably no clue about this particular package