Clarification on upstart-0.5 and dbus usage

[Casey Dahlin]

Garrett Cooper wrote:
> On Wed, Jun 18, 2008 at 1:11 PM, Casey Dahlin <cdahlin at redhat.com> wrote:
>   
>> Garrett Cooper wrote:
>>     
>>> Hi again,
>>>      There have been a flurry of emails passed internal dev lists,
>>> and I believe (given past experience with dbus) there is some
>>> confusion as to what the role is of dbus in the upstart project.
>>>      So, I was wondering if someone could briefly discuss from a
>>> high-level what dbus is going to do within upstart, or point me to [a
>>> series of] link[s] with more information about the architectural
>>> interfacing between upstart, dbus, and monitored processes.
>>> Thanks,
>>> -Garrett
>>>
>>>
>>>       
>> DBus is used to give instructions to upstart (start this, stop that) and get
>> information from it (this is now running. This has stopped).
>>
>> The DBus interface can be accessed in one of 2 ways. One is actually running
>> the dbus daemon, and accessing the com.ubuntu.Upstart object on the system
>> bus. The other is by connecting directly to upstart through the
>> /com/ubuntu/Upstart unix-domain socket and communicating in DBus protocol.
>>
>> --CJD
>>     
>
> Ok, so there isn't a means to control upstart from a terminal screen,
> exec, system, or something simple without knowing the API's or
> "talking dbus" if need be? I assume that's due (in part) to the
> chicken-and-egg issue provided by init spawning a terminal.
> -Garrett
>
>   

There are command line tools that will be provided, but they will be 
communicating to Upstart via the DBus protocol. You don't need to know 
the DBus API to use them, by any means, but your system does need to 
provide the library.

--CJD