Ubuntu – Access dbus session bus from upstart script

dbusupstart

I was wandering if it is possible to access the DBUS session bus from within an upstart script.

The background is this:
I am running an upstart task in user mode and replaced the Upstart.conf dbus configuration file with the one from the upstart bzr repository.

Now it would like to access the gnome keyring within that tasks script using gkeyring, which needs to access the users upstart session bus. By default, I just get the Gnome keyring not available.

When I try to export DBUS_SESSION_BUS_ADDRESS=... within the upstart script, the script/initctl command just hangs, no output anywhere.

This leads me to believe that since upstart uses DBUS as well, using the session bus is problematic. Does someone have an idea to resolve this?

Best Answer

this might work for you ?...

script
    export HOME="/home/puma"
    chdir /home/puma/apps/whatever/bin
    dbus_file=$(ls $HOME/.dbus/session-bus/ -t1 | head -1)
    . "$HOME/.dbus/session-bus/$dbus_file"
    export DBUS_SESSION_BUS_ADDRESS
    exec su -s /bin/sh -c 'export DBUS_SESSION_BUS_ADDRESS=$DBUS_SESSION_BUS_ADDRESS;exec /home/puma/apps/whatever/bin/appname' puma 
end script

hope it helps ?

Related Solutions

Upstart – Upstart Script and Start-Stop-Daemon

I can't be entirely sure but inspircd might be forking out the way when it's run so Upstart doesn't know where its PID really is. If that's the case, it can be fixed because Upstart has two stanzas for handling forking processes:

expect fork catches processes that fork once (imo, most likely the case here).
expect daemon catches things that fork out twice... Which this may be doing.

So try this:

description "IRC Daemon Upstart Script"

start on startup
start on runlevel [2345]
stop on runlevel [016]

respawn
expect fork

nice -5

exec su bash -c "cd /home/ircuser/inspircd/run; /home/ircuser/inspircd/run/bin/inspircd -- --config=./conf/inspircd.conf" ircuser

And if that doesn't work, check my su-statement to make sure it works from the command line and then change expect fork to expect daemon and give it another whirl.

Edit the bash wrapper might be doing it more harm than good. This might be a better exec:

exec sudo -u ircuser /home/ircuser/inspircd/run/bin/inspircd -- --config=/home/ircuser/inspircd/run/conf/inspircd.conf

GConf Error: No D-BUS Daemon Running – How to Reinstall or Fix

SirCharlo's answer worked for me. Same problem on ubuntu 12.04 (precise pangolin). Yeah, I use su (root) also. Shame, shame. Same problem starting emacs too.

The problem seems to be that DBUS_SESSION_BUS_ADDRESS retains its value when you su instead of picking up the value in /root/.dbus/session-bus/

from man dbus-launch:

   ...
   The second common reason for autolaunch is an su to another  user,  and
   display  of  X  applications  running as the second user on the display
   belonging to the first user. Perhaps the ideal fix in this  case  would
   be  to allow the second user to connect to the session bus of the first
   user, just as they can connect to the first user's display.  However, a
   mechanism for that has not been coded.
   ...

Use sudo, suedit, gksu.

Or if you MUST use su, then try adding this to your /root/.bashrc:

sessionfile=`find "${HOME}/.dbus/session-bus/" -maxdepth 1 -type f`
if [ -f "$sessionfile" ] ; then
    if grep -q "^DBUS_SESSION_BUS_ADDRESS=" "${sessionfile}" ; then
        export `grep "^DBUS_SESSION_BUS_ADDRESS=" "${sessionfile}"`
    else
        echo "DBUS_SESSION_BUS_ADDRESS not found in ${sessionfile}"
    fi
else
    echo "no session address file found in ${HOME}/.dbus/session-bus"
fi

Best Answer

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Upstart – Upstart Script and Start-Stop-Daemon

GConf Error: No D-BUS Daemon Running – How to Reinstall or Fix

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