Re: elogind status

[Thompson, David]

On Fri, Aug 21, 2015 at 11:19 AM, 宋文武 <address@hidden> wrote:
> Andy Wingo <address@hidden> writes:
>
>> Hi :)
>>
>> [...]
>>
>> The result is https://github.com/andywingo/elogind.  It provides:
>>
>>   * a logind-compatible API with a different library name, libelogind
>>
>>   * a pkg-config file, libelogind.pc
>>
>>   * a daemon, elogind
>>
>>   * a PAM module, pam_elogind.so
>>
>>   * a query/control utility, loginctl
>>
>> It might be worth it to install more compatibility interfaces for
>> systemd, e.g. libsystemd.so, or a symlink for <systemd/sd-login.h> to go
>> to <elogind/sd-login.h>.  Or perhaps we should just provide the systemd
>> header files with the systemd names.  In practice this means that
>> building packages that use the C interfaces need a bit more munging in
>> Guix to replace names.
> Yeah, as seen in your polkit patch.
>>
>> In the patches I sent to this list, we have also a service which runs
>> elogind, and the facilities to integrate pam_elogind.so with the rest of
>> the system.  The PAM integration is really horrible and I'd be
>> interested in other options; see footnote for my os-config.scm.
>>
>> Upstream logind integrates with systemd to ensure that user sessions are
>> run in cgroups, which is a pretty neat feature.  They manage cgroups
>> with a hierarchical "slice" abstraction.  Perhaps DMD should do this at
>> some point.  Using cgroups also lets logind know when a process was
>> started by a user but the user has logged out, and optionally lets the
>> administrator kill user processes when they log out.  So, elogind will
>> expose information about users, sessions, and seats, but for now not
>> slices.  Most logind users don't care so this is OK.

> Thanks for the detail explaination, maybe we can use cgmanager somehow
> later: <https://github.com/lxc/cgmanager>

I think I'm opposed to this.  I say "I think" because I haven't done
all of my homework yet, but I am just starting to write a Scheme
interface to cgroups for use with 'call-with-container' so I've
learned a thing or two.  I'd like to see dmd use cgroups like systemd
does, but I don't think we need to bring in any LXC tools to do it.
All the LXC stuff I've looked at has been too high level to be useful
to us.  Guile has everything we need. :)

- Dave