def removeHost(self, serverName):
		role_mappings_file_name = "/etc/puppet/data/role_mappings.yaml"

		if not os.path.exists(role_mappings_file_name):
			logging.debug("File role_mappings.yaml is not present, No need to proceed further")
			return
		pass
	
                logging.debug('removing Host from Openstack %s' % serverName)
                logging.debug("In Openstack.removeHost()")
                role_mappings_file = open(role_mappings_file_name, "r")
                yaml_role_mappings = yaml.safe_load(role_mappings_file)
                role_mappings_file.close()

                #check if the node already exists.
                if yaml_role_mappings and yaml_role_mappings.keys() and serverName in yaml_role_mappings.keys():
			del yaml_role_mappings[serverName]
			# Write the remaining nodes to yaml DB and do 'puppet apply'
			role_mappings_file = open("/etc/puppet/data/role_mappings.yaml", 'w')
			yaml.safe_dump(yaml_role_mappings, role_mappings_file, default_flow_style=False)
			role_mappings_file.close()
			#self.updateSiteFile()

			# Need to remove the entry in cobbler
	                logging.debug('Removing Host from cobbler %s' % serverName)
        	        removeHost(serverName)
			return	
		else:
			logging.debug('role_mappings.yaml is empty or key doesn\'t exists.')
		pass
This function removes the system from the Openstack configuration
dataset/ETHPy150Open Havate/havate-openstack/proto-build/gui/horizon/Horizon_GUI/openstack_dashboard/static-raw/scripts/SPConsumer.py/Openstack.removeHost