def configure_job_flow(job_flow)
        ec2_key_name = config_setting('ec2_key_name')
        placement = config_setting('placement')
        emr_ami_version = config_setting('emr_ami_version')
        job_flow_role = config_setting('job_flow_role')
        service_role = config_setting('service_role')
        ec2_subnet_id = config_setting('ec2_subnet_id')

        job_flow.ec2_subnet_id = ec2_subnet_id if ec2_subnet_id.present?
        job_flow.ec2_key_name = ec2_key_name if ec2_key_name.present?
        job_flow.placement = placement if placement.present?
        job_flow.ami_version = emr_ami_version if emr_ami_version.present?
        job_flow.job_flow_role = job_flow_role if job_flow_role.present?
        job_flow.service_role = service_role if service_role.present?
    end
def configure_job_flow(job_flow)
        ec2_key_name = config_setting('ec2_key_name')
        placement = config_setting('placement')
        emr_ami_version = config_setting('emr_ami_version')
        job_flow_role = config_setting('job_flow_role')
        service_role = config_setting('service_role')
        ec2_subnet_id = config_setting('ec2_subnet_id')

        job_flow.ec2_subnet_id = ec2_subnet_id if ec2_subnet_id.present?
        job_flow.ec2_key_name = ec2_key_name if ec2_key_name.present?
        job_flow.placement = placement if placement.present?
        job_flow.ami_version = emr_ami_version if emr_ami_version.present?
        job_flow.job_flow_role = job_flow_role if job_flow_role.present?
        job_flow.service_role = service_role if service_role.present?
    end
Set job flow properties from settings in cluster.yml.