New Feature: Watchdog that reboots the system if the screen stops cha…

…nging

Makefile

@@ -7,10 +7,10 @@ DPKG_OPTS=-b
 	cp -r src build
 	git log | gzip -9 >build/usr/share/doc/kiosk-browser/changelog.gz
 	chmod -R g-w build
+	chmod 0440 build/etc/sudoers.d/kiosk-browser
+	visudo -c -f build/etc/sudoers.d/kiosk-browser
 	fakeroot ${DPKG} ${DPKG_OPTS} build out
 	rm -Rf build
-
-test: out/*.deb
 	lintian -i out/*.deb
 
 info: out/*.deb

src/DEBIAN/conffiles

@@ -0,0 +1 @@
+/etc/sudoers.d/kiosk-browser

src/DEBIAN/control

@@ -1,15 +1,17 @@
 Package: kiosk-browser
-Version: 1.18
+Version: 1.20
 Priority: optional
 Section: web
 Architecture: all
 Maintainer: Schlomo Schapiro <[email protected]>
 Pre-Depends: nodm
-Depends: chromium-browser, x11-xserver-utils, metacity, xdotool
+Depends: chromium-browser, x11-xserver-utils, metacity, xdotool, x11-apps, sudo, imagemagick
 Homepage: https://github.com/ImmobilienScout24/kiosk-browser
 Description: Kiosk Browser 
  Setup system to work as a kiosk browser, showing only a full-screen browser.
  .
  Configuration options in /etc/default/kiosk-browser 
    KIOSK_BROWSER_START_PAGE sets the start page
  Also add your own customization to that file, e.g. xrandr calls.
+ .
+ See project homepage for full list of config options.

src/DEBIAN/postinst

@@ -14,3 +14,10 @@ sed -i -e 's/NODM_X_OPTIONS=.*/NODM_X_OPTIONS="-nocursor -nolisten tcp"/' -e 's/
 # allow kiosk user to only write in directories needed by chromium
 mkdir -p /var/lib/kiosk-browser/{.cache,.config/chromium,.pki}
 chown -R kiosk-browser:kiosk-browser /var/lib/kiosk-browser/{.cache,.config/chromium,.pki}
+
+# restart if running, nodm has no status so we simply check for any kiosk-browser processes
+if pgrep -u kiosk-browser >/dev/null ; then
+    service nodm stop
+    sleep 20 # wait for chromium and other subprocesses to exit
+    service nodm start
+fi

src/etc/sudoers.d/kiosk-browser

@@ -0,0 +1 @@
+kiosk-browser ALL=NOPASSWD: /sbin/reboot

src/var/lib/kiosk-browser/.xsession

@@ -32,6 +32,11 @@ if [[ ! "$KIOSK_BROWSER_START_PAGE" ]] ; then
 	KIOSK_BROWSER_START_PAGE=https://github.com/ImmobilienScout24/kiosk-browser
 fi
 
+if [[ ! "$KIOSK_BROWSER_WATCHDOG_TIMEOUT" ]] ; then
+    # default stale screen watchdog is 1h
+    KIOSK_BROWSER_WATCHDOG_TIMEOUT=3600
+fi
+
 # configure displays
 xrandr $(
 	xrandr_position=
@@ -51,6 +56,26 @@ xset -dpms
 xset s off
 xset s noblank
 
+# start watchdog, reboot system if screen stops to change
+if (( KIOSK_BROWSER_WATCHDOG_TIMEOUT > 0 )) ; then
+    LASTHASH=""
+    LASTCHANGED="$SECONDS"
+    while sleep "${KIOSK_BROWSER_WATCHDOG_CHECK_INTERVAL:-17}" ; do 
+        HASH=$(import -display :0 -window root -monochrome jpg:- | identify -format '%#' -)
+        #declare -p HASH LASTHASH LASTCHANGED SECONDS
+        if [[ "$HASH" = "$LASTHASH" ]] ; then 
+            if (( SECONDS > LASTCHANGED + KIOSK_BROWSER_WATCHDOG_TIMEOUT )) ; then
+                sudo /sbin/reboot
+                break
+            fi
+        else
+            LASTHASH="$HASH"
+            LASTCHANGED="$SECONDS"
+        fi
+    done </dev/null 1>&2 &
+    trap "kill $!" 0 # kill watchdog on exit
+fi
+
 #forget about running jobs
 disown -a