GNU dmd road map

[Ludovic Courtès]

Hello!

Here’s a tiny road map I’ve come up with for dmd.

First I’m hoping to release 0.1 within a couple of weeks, just before
Guix 0.5.  I’ve added support for power-off/reboot recently, where dmd
first stops all the services (yeah, that’s pretty useful ;-)).  Other
things I’d want for 0.1 is a ‘shutdown’ command, and removing one last
use of a Guile deprecated interface (in comm.scm).

Then we’ll need to finish runlevel support; dmd is inherently
service-oriented (like Upstart), but runlevels are obviously useful in a
number of contexts.  That could be a goal for 0.2.

Several people pointed out how Linux cgroups are cool, and how systemd
makes good use of them.  The cgroups “API” is essentially a set of text
files in the /sys file system [0] (there’s on-going work to implement
that interface on the Hurd [1].)  Among other things, using it would
allow dmd to keep track of all the processes started by a given service.
We would first write bindings to cgroups, and then use them to start
each service in its own cgroup.

We’ll need to be able to react to udev events on Linux-based systems
(such as “eth0 is up”, etc.)  Services should be able to declare what OS
event(s) they’re waiting for.  A possible source of inspiration is
upstart-udev-bridge [2].

There’s also regular maintenance work to do: coming up with a testing
strategy, proper internationalization, perhaps using SRFI-37 instead of
args.scm, etc.

Comments and patches welcome!  :-)

Thanks,
Ludo’.

[0] https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt
[1] http://lists.debian.org/debian-hurd/2013/09/msg00062.html
[2] http://upstart.ubuntu.com/cookbook/#upstart-udev-bridge