[systemd-devel] systemd-firstboot skip root password initialisation if /etc/shadow is present

[David Herrmann]

Hi

On Tue, Sep 22, 2015 at 2:26 PM, Francis Moreau <francis.moro at gmail.com> wrote:
> On Tue, Sep 22, 2015 at 12:19 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
>> On Tue, Sep 22, 2015 at 11:59 AM, Francis Moreau <francis.moro at gmail.com> wrote:
> [...]
>>>
>>> Well during package installation done by the installer, some packages,
>>> usually the ones that installs daemons/services, populates
>>> /etc/shadow.
>>>
>>> On Archlinux, after creating a minimal rootfs, shadow file is containing:
>>>
>>> bin:x:14871::::::
>>> daemon:x:14871::::::
>>> mail:x:14871::::::
>>> ftp:x:14871::::::
>>> http:x:14871::::::
>>> uuidd:x:14871::::::
>>> dbus:x:14871::::::
>>> nobody:x:14871::::::
>>> systemd-journal-gateway:x:14871::::::
>>> systemd-timesync:x:14871::::::
>>> systemd-network:x:14871::::::
>>> systemd-bus-proxy:x:14871::::::
>>
>> Then "fix" the installer? These entries look like no-ops to me. We
>> assume that if the installer touches /etc, then it can as well prompt
>> for a root-password. If you want to make use of firstboot, we
>> recommend to adopt an "empty /etc" installer.
>
> That's not about the installer, it's about packages and I suspect that
> very few are ready to run without /etc.

Ok, then fix those packages.

> And then if it's really the case, I think the man page of
> systemd-firstboot should be fixed because it never mentions the words
> "stateless" or "empty", which is quite fundamental in the design of
> firstboot then.
>
>>
>> If we support looking for "root" in shadow files and prompt if
>> non-present, we start supporting legacy setups where /etc is
>> half-populated. We don't want that. Either go full legacy and make
>> your installer prompt for everything, or go "empty /etc" and firstboot
>> will take over.
>>
>
> What you're calling legacy systems are actually *all* systems
> available out there: I don't think there's a actually a lot of
> packages which are prepared to do that.

We fix the packages we care about. I encourage everyone to do the
same. All upstream systemd can do is provide a guideline.

>>>>
>>>>> BTW, I don't know if recovering when /etc/ has been deleted is
>>>>> possible even if systemd-firstboot will restore a couple of conf
>>>>> files...
>>>>
>>>> Depending on your distribution, it is.
>>>
>>> Just out of curiosity, which distros are supposed to support that ?
>>
>> I can trash /etc on Archlinux and boot it as a container just fine. It
>> doesn't work as a full system, yet.
>
> Sure but what's your point ? your container is running no service at
> all, so it's pretty useless.

Why? You can store static configuration in /usr just fine. The point
is to get rid of _runtime_ configuration in /etc that can be modified.
Instead, you should ship vendor configuration via /usr (or
/usr/factory if packages are broken), and make it *read-only*.

>> Not all packages have adopted empty /etc support.
>
> You meant almost none of them ?

No.

Thanks
David