Trying to modify run.sh so it waits for the Xvfb server to start accepting connections.

run.sh

@@ -1,36 +1,27 @@
 #!/bin/bash
 
-# Find an open port
-let p=99
-while [ ${p} -lt 3000 ]
- do
-    if nc -z localhost ${p}; then
-        let p+=1
-    else
-        let port=p
-        break
-    fi
- done
+function LOG {
+    echo $(date -R): $0: $*
+}
 
-let timeout=20
+displayNumber=1
+screenNumber=0
+export DISPLAY=:${displayNumber}.${screenNumber}
 
-if [ "${port}" != "" ]; then
-    echo "The display port will be ${port}."
+LOG "Starting Xvfb on ${DISPLAY}"
     start-stop-daemon --start --pidfile ~/xvfb.pid --make-pidfile --background \
-        --exec /usr/bin/Xvfb -- :${port} -screen 0 1024x768x24 \
+        --exec /usr/bin/Xvfb -- :${displayNumber} -screen ${screenNumber} 1024x768x24 \
         -ac +extension GLX +render -noreset
 
-    # Wait to be able to connect to the port. This will exit if it cannot in 15 minutes.
-    timeout ${timeout} bash -c "while ! nc -z localhost ${port}; do sleep 0.5; done"
-    if [ $? -eq 0 ]; then
-        export DISPLAY=:${port}.0
+LOG "Waiting for display at ${DISPLAY}."
 
+# Wait to be able to connect to the port. This will exit if it cannot in 15 minutes.
+timeout ${timeout} bash -c "while  ! xdpyinfo >/dev/null 2>&1; do sleep 0.5; done"
+if [ $? -eq 0 ]; then
+    LOG "Display ${DISPLAY} is up."
+    LOG "Starting tileserver"
     cd /data
     node /usr/src/app/ -p 80 "$@"
 else
-      echo "Could not connect to display port ${port} in ${timeout} seconds time."
-    fi
-else
-    echo "Could not get a display port."
-    exit 1
+  LOG "Could not connect to display port ${DSIPLAY} in ${timeout} seconds time."
 fi