Wait for Xvfb to startup

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:6-stretch
+FROM node:6.15.1-stretch
 MAINTAINER Petr Sloup <petr.sloup@klokantech.com>
 
 ENV NODE_ENV="production"
@@ -21,6 +21,7 @@ RUN apt-get -qq update \
     libprotobuf-dev \
     libxxf86vm-dev \
     xvfb \
+    x11-utils \
 && apt-get clean
 
 RUN mkdir -p /usr/src/app

run.sh

@@ -5,17 +5,29 @@ _term() {
 	kill -TERM "$child" 2>/dev/null
 }
 
-trap _term TERM
+trap _term SIGTERM
+trap _term SIGINT
+
+xvfbMaxStartWaitTime=5
+displayNumber=99
+screenNumber=0
 
 # Delete files if they were not cleaned by last run
-rm -rf /tmp/.X11-unix /tmp/.X99-lock
+rm -rf /tmp/.X11-unix /tmp/.X${displayNumber}-lock ~/xvfb.pid
+
+echo "Starting Xvfb on display ${displayNumber}"
+start-stop-daemon --start --pidfile ~/xvfb.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :${displayNumber} -screen ${screenNumber} 1024x768x24  -ac +extension GLX +render -noreset
 
-start-stop-daemon --start --pidfile ~/xvfb.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -screen 0 1024x768x24 -ac +extension GLX +render -noreset
-echo "Waiting 3 seconds for xvfb to start..."
-sleep 3
+# Wait to be able to connect to the port. This will exit if it cannot in 15 minutes.
+timeout ${xvfbMaxStartWaitTime} bash -c "while  ! xdpyinfo -display :${displayNumber} >/dev/null; do sleep 0.5; done"
+if [ $? -ne 0 ]; then
+  echo "Could not connect to display ${displayNumber} in ${xvfbMaxStartWaitTime} seconds time."
+  exit 1
+fi
 
-export DISPLAY=:99.0
+export DISPLAY=:${displayNumber}.${screenNumber}
 
+echo
 cd /data
 node /usr/src/app/ -p 80 "$@" &
 child=$!