dinit/TODO

For version 0.6.0:
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* Refuse to start new services during shutdown.
* On service failure (all services stop when no restart issued), allow user to interrupt/ctrl+alt+del when
  they are prompted to press enter, to allow halt/rebooting instead of re-launching the boot service. 
* Basic resource limits setting.
* per-service environment.

For version 0.7.0:
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? Not decided yet.

For version 1.0:
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* "triggered" service type: external process notifies Dinit when the service
  has started. (maybe?)
* on shutdown, after repeated intervals with no activity, display information
  about services we are waiting on (or, do this when prompted via ^C or C-A-D).
* Documentation must be complete (see section below).
* Proper support for socket activation?
* Be able to boot and shutdown Linux and FreeBSD.

For later:
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* On linux when running with PID != 1, write PID to /proc/sys/kernel/cad_pid so
  that we still receive SIGINT from ctrl+alt+del (must be done after /proc is
  mounted, possibly could be left to a service script)
* Perhaps need a way to prevent script services from re-starting.
  (eg there's no need to mount filesystems twice; there might be various other
   system initialisations that can't or shouldn't really be "undone" and so do
   not need to be re-done).
* Internationalisation
* A service can prevent shutdown/reboot by failing to stop. Maybe make
  multiple CTRL-ALT-DEL presses (or ^C since that's more portable) commence
  immediate shutdown (or launch a simple control interface).
* When we take down a service or tty session, it would be ideal if we could kill
  the whole process tree, not just the leader process (need cgroups or pid
  namespace or other mechanism).
* Allow logging tasks to memory (growing or circular buffer) and later
  switching to disk logging (allows for filesystem mounted readonly on boot).
  But perhaps this really the responsibility of another daemon.
* Allow running services with different resource limits, chroot, cgroups,
  namespaces (pid/fs/uid), etc
* Support chaining service output to another process (logger) input; if the
  service dies the file descriptor of its stdout isn't closed and is reassigned
  when the service is restarted, so that minimal output is lost.
  - even more, it would be nice if a single logger process could be responsible
    for receiving output from multiple services. This would require some kind of
    protocol for passing new output descriptors to the logger (for when a
    service starts).

Even later / Maybe never:
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* Support recognising /etc/init.d services automatically (as script services, with
  no dependency management - or upstart compatible dependency management)
  Also BSD's rc.d style scripts (PROVIDE, REQUIRE).
* Place some reasonable, soft limit on the number of services to be started
  simultaneously, to prevent thrashing. Services that are taking a long time
  to start don't count to the limit. Maybe use CPU/IO usage as a controlling
  factor.
* Cron-like tasks (if started, they run a sub-task periodically. Stopping the
  task will wait until the sub-task is complete). 
* Allow to run services attached to virtual tty, allow connection to that tty (ala "screen").
* SystemD-like handling of filesystem mounts (see autofs documentation in kernel)
  i.e. a mount point gets an autofs attached, and lazily gets mounted when accessed
  (or is mounted in parallel). Probably put the functionality in a separate daemon.


Documentation:
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* Design philosophy/rationale document
* Coding style guidelines

* What's the best TERM setting? gogetty gives me "linux" but I think other variants may be
  better (eg "linux-c").

* Figure out the ConsoleKit/logind / PolicyKit mess & how dinit needs to fit into it.
  * Consolekit/logind tracks "sessions". Provides a mechanism to mark a session starting,
    associates processes with sessions, provides calls to terminate sessions etc (why?!!)
    Can use environment variable or cgroups to track processes in a session.
    A PAM module exists to create/destroy sessions.
  * Consolekit/logind also allows for requesting shutdown, reboot, and inhibiting reboot
    (via dbus API).
  * "seats" are a set of input/output hardware (mouse/keyboard/monitor) on which a session
    can be run. You can have multiple sessions on a seat - one is in the foreground
    (eg linux virtual ttys implement multiple sessions on a single seat).
    Sessions can run without a seat (eg ssh session).