thanks @Luca_Belluccini ......
if i am not wrong this is the one which will be used by the filebeat
but it doesn't contain any alias even though i read that ILM policy will be used by defualt in elasitc 7.x ........ and in order to roll over you need to have the alias .... can you tell me from where and how does it will be able to get that alias for the template