add waiter after creating instances

aws-experiment-launch/create_instances.py

@@ -77,6 +77,11 @@ def create_instances(config, ec2_client, region_number, number_of_instances):
         ],
     )
 
+    instance_ids = utils.get_instance_ids2(ec2_client, node_name_tag)
+    LOGGER.info("Waiting for all %d instances in region %s to be in RUNNING" % (len(instance_ids), region_number))
+    waiter = ec2_client.get_waiter('instance_running')
+    waiter.wait(InstanceIds=instance_ids)
+
     count = 0
     while count < 40:
         time.sleep(5)