How to use arithmetic when setting a variable value in Ansible?

Question

I would like to use a system fact for a host times a number/percentage as a base for a variable. What I am trying to do specifically is use the ansible_memtotal_mb

Answer 1

One little thing to add. If you presume the math multiplication has precedence before jinja filter (| sign), you're wrong ;-)

With values like

total_rate: 150
host_ratio: 14 # percentual

"{{ total_rate*host_ratio*0.01|int }}" => 0 because 0.01|int = 0
"{{ (total_rate*host_ratio*0.01)|int) }}" => 21 as one expects