add code to make sure instance is ready

demo-2/script.sh

@@ -1,3 +1,13 @@
 #!/bin/bash
+
+# sleep until instance is ready
+until [[ -f /var/lib/cloud/instance/boot-finished ]]; do
+  sleep 1
+done
+
+# install nginx
 apt-get update
 apt-get -y install nginx
+
+# make sure nginx is started
+service nginx start