How to lock session from awesome

Question

I wish to have a simple locking feature in Awesome on Ubuntu 13.10, both on demand and on inactivity.

Answer 1

Get recipe inredients:

sudo apt-get install xautolock slock

• xautolock - executes a locker after a period of inactivity.
• slock - locks the screen wit a black only UI, type password and hit Enter.

try the command to lock the session first and see if you like it:

slock

This can be hooked into Awesome menu by modifying it's config:

# make awesome config dir:
mkdir -p ~/.config/awesome

# copy default config file to your home folder:
cp /etc/xdg/awesome/rc.lua ~/.config/awesome

# edit the custom config:
nano ~/.config/awesome/rc.lua

Find where the mymainmenu is being built and adjust it. My section now looks like this (note the "Lock" line):

lockscreen = function() awful.util.spawn("slock") end

mymainmenu = awful.menu({ items = {
            { "Lock", lockscreen },
            { "Awesome", myawesomemenu, beautiful.awesome_icon },
            { "Debian", debian.menu.Debian_menu.Debian },
            { "Guest", terminal .. " -e /usr/bin/dm-tool switch-to-guest" },
            { "Greet", terminal .. " -e /usr/bin/dm-tool switch-to-greeter" },
            { "Logout", awesome.quit },
         } 
      })

And make a Meta+Escape shortcut for it too. Originally Escape is bound to tag history. I don't use that feature though.

-- it was:
--    awful.key({ modkey,           }, "Escape", awful.tag.history.restore),
    awful.key({ modkey,           }, "Escape", lockscreen               ),

Then comes the automatic locking. I created an executable file to make sure that xautolock only executes once per session:

# make a bin folder if not present:
mkdir -p ~/bin/

# make the file, set permissions and edit:
touch ~/bin/session-daemon
chmod ug+x ~/bin/session-daemon
nano ~/bin/session-daemon

I used an environment variable "XDG_SEAT" which is set by the DM to distinguish sessions and store a PID and log of the command. It is only executed if not running already:

#!/bin/bash

if [ "$#" == "0" ] ;
then
    echo "Session daemon missing command" >&2
    echo "USAGE: $0 command [args...]"
    echo "Executes given command with args only once per XDG seat (session)."
    echo "Keeps PID and log of the executed command."
    exit 1
fi

COMMAND=$1
shift

NAME="${COMMAND##*/}"
PIDFILE=~/.cache/session-daemon/$NAME-$XDG_SEAT.pid
LOGFILE=~/.cache/session-daemon/$NAME-$XDG_SEAT.log
PID=""
PIDDIR="${PIDFILE%/*}"
LOGDIR="${LOGFILE%/*}"

mkdir -p $PIDDIR
if [ $? -ne 0 ];
then
    echo "Session daemon PIDDIR not there: $PIDDIR" >&2
    exit 2
fi

mkdir -p $LOGDIR
if [ $? -ne 0 ];
then
    echo "Session daemon LOGDIR not there: $LOGDIR" >&2
    exit 2
fi

if [ -e "$PIDFILE" ] ; 
then 
    echo "Session daemon '$NAME' PIDFILE found: $PIDFILE"
    PID=`cat "$PIDFILE"` 
    echo "Session daemon '$NAME' PID found: $PID"
else
    echo "Session daemon '$NAME' PIDFILE NOT found: $PIDFILE"
fi

if [ "$PID" ] && kill -0 "$PID" 2>/dev/null ; 
then
    echo "Session daemon '$NAME' was already running with PID $PID" >&2
    exit 3
fi

echo "Session daemon running $COMMAND $* > $LOGFILE 2>&1"
$COMMAND $* > "$LOGFILE" 2>&1 &
PID=$!
ERR=$?
sleep 1

if [ "$PID" ] && [  $ERR == 0 ] && kill -0 "$PID" 2>/dev/null;
then
    echo -n $PID > "$PIDFILE"
    echo "Session daemon '$NAME' started with PID $PID"
else
    echo "Session daemon '$NAME' did not start or finished early. PID: $PID, ERR: $ERR" >&2
    cat "$LOGFILE" >&2
    exit 4
fi

That session-daemon script will be used by the xautolock-session:

# make the file, set permissions and edit:
touch ~/bin/xautolock-session
chmod ug+x ~/bin/xautolock-session
nano ~/bin/xautolock-session

xautolock-session content:

#!/bin/bash

session-daemon xautolock -locker slock -time 5 -detectsleep -secure -corners "-00+"

That will be executed by Awesome on restart. Edit the Awesome config again:

nano ~/.config/awesome/rc.lua

And add this line at the bottom:

awful.util.spawn_with_shell("~/bin/xautolock-session")

Now when you log out and in again, your session will be automatically locked after 5 minutes.

Note: We could use dm-tool lock, too, but there's a freaky bug that actually breaks the whole idea: Lock can be circumvented by switching to console