Ansible playbook: Check root filesystem usage

Everything
1

Here is a snippet I use to quickly check an inventory of hosts in ansible on how much disk space they have remaining / visually alert me to see if any hosts are for example exceeding >90 % usage for the root mount and ignore other mounts.

You can modify this variable to alert you based on what % filled the root mount is

usage_threshold_percent: 90

---
- name: Check root filesystem usage
  hosts: all
  user: root
  gather_facts: true

  vars:
    usage_threshold_percent: 90

  tasks:
    - name: Locate root mount info
      set_fact:
        root_mount: "{{ ansible_facts.mounts | selectattr('mount', '==', '/') | list | first }}"
      when: ansible_facts.mounts is defined

    - name: Compute root filesystem used percent
      set_fact:
        root_used_percent: "{{ (100 - ((root_mount.size_available | float) / (root_mount.size_total | float) * 100)) | round(2) }}"
      when:
        - root_mount is defined
        - root_mount.size_total is defined
        - (root_mount.size_total | float) > 0

    - name: Report high root filesystem usage
      debug:
        msg: "Host {{ inventory_hostname }}: / is at {{ root_used_percent }}% used (>= {{ usage_threshold_percent }}%)"
      when:
        - root_used_percent is defined
        - (root_used_percent | float) >= (usage_threshold_percent | float)

output will look like this (assuming the host has more than 10% available disk space

skipping: [24-trello]
skipping: [24-spotted]
skipping: [24-calculator]
skipping: [24-post-silver]
skipping: [24-post-jealous]
skipping: [24-post-lazy]
skipping: [24-post-lollypop]
skipping: [24-post-museum]
skipping: [24-post-sirius]
skipping: [24-bollywood]
skipping: [24-happyhippo]
skipping: [24-stop122]
skipping: [24-marketlane]
skipping: [24-smiling-child]
skipping: [24-bst]
skipping: [24-kinopio]
skipping: [24-sanga]
skipping: [24-diagram]
skipping: [24-emporium]
skipping: [24-englishbreakfast]
skipping: [24-cocacola]
2

Here’s a better example of the output that includes a server with too much used disk space

TASK [Report high root filesystem usage] ***************************************************************************************************************************************************************************
skipping: [do-scrapingapi-nomad-server-1]
skipping: [do-scrapingapi-nomad-server-2]
skipping: [do-scrapingapi-nomad-server-3]
skipping: [do-scrapingapi-consul-sf-1]
skipping: [do-scrapingapi-consul-sf-2]
skipping: [do-scrapingapi-consul-sf-3]
skipping: [24-new-eczema]
skipping: [24-post-coffee]
skipping: [24-mrfox]
skipping: [rackdog-zealous-alpaca]
skipping: [rackdog-node5]
skipping: [rackdog-node4]
ok: [rackdog-carpet] => {
    "msg": "Host rackdog-carpet: / is at 100.0% used (>= 90%)"
}
skipping: [rackdog-bin]
skipping: [24-rubato]
skipping: [24-hungry-noisy]