ansible: sum over fact array

Question

I want to get disk sizes of multiple disks and sum them to check if the sum of their sizes is greater than the minimum required.

We are going to use LVM to create mountpoints, we need to be able to use singe disk or multiple disks.

I'm able to get individual disk sizes using ansible facts ( ansible_devices.items.sectors|int * ansible_devices.items.sectorsize|int) using with_items

I want to sum all of these. How do I do that

Solution

There are map and sum filters in Jinja:

- set_fact:
    disk_size: "{{ (item.value.sectors | int) * (item.value.sectorsize | int) }}"
  with_dict: "{{ ansible_devices }}"
  register: disk_sizes

- debug: msg="{{ disk_sizes.results | map(attribute='ansible_facts.disk_size') | map('int') | sum(start=0) }}"

Comments

[Matt]

Have you considered using the Python API for ansible docs.ansible.com/ansible/dev_guide/…?