apache/spark — pull request #3596 by alexdebrie (2014-12-04 04:24:59+00:00)
Title: Fix get_existing_cluster() function with multiple security groups

The current get_existing_cluster() function would only find an instance belonged to a cluster if the instance's security groups == [cluster_name + "-master"] (or "-slaves"). This fix allows for multiple security groups by checking if the cluster_name + "-master" security group is in the list of groups for a particular instance.