Check if docker is installed

Author: joanhey

apache.sh

@@ -1,3 +1,10 @@
+#!/bin/sh
+
+if [ ! `which docker` ]; then
+    echo "docker not found."
+    exit 1;
+fi
+
 docker build --tag bench/apache -f .docker/apache.dockerfile .
 
 echo "Runing apache in http://127.0.0.1:8080"