Ansible and hardware checks

14,889

There are a few things wrong with the snippet you posted.

  • Your indentation is off. tasks needs to be at the same indentation level as hosts.

  • The when condition needs to be part of the fail task block, not a separate list item.

  • In general, you do not need to use {{ ... }} in a when condition, the entire expression will be treated as a Jinja template.

Try this:

- hosts: client
  remote_user: user
  tasks:
    - debug: var=ansible_memory_mb
    - debug: msg="total RAM is {{ ansible_memory_mb.real.total }}"
    - fail: msg="not enough RAM"
      when: ansible_memory_mb.real.total < 4096

You can also use the assert module to check a condition or list of conditions.

- assert:
    that:
      - ansible_memory_mb.real.total >= 4096
      - some other condition
      - ...
Share:
14,889

Related videos on Youtube

Matthew
Author by

Matthew

Updated on June 04, 2022

Comments

  • Matthew
    Matthew almost 2 years

    I have to check different hardware and configurations elements on Linux machines using ansible, and I am not sure at all about how to do it (RAM, disk space, DNS, CPU...), I've understood that I can find nearly all I want in the ansible facts, but I do not understand how I can use it.

    For example, I have to check if the RAM amount is at least of 4GB and have an alarm if not, so I tried many things, and... nothing works.

    Here is an example of what I tried.

     - hosts: client
       remote_user: user
    
      tasks:
          - debug: var=ansible_memory_mb
          - debug: msg="total RAM is {{ ansible_memory_mb.real.total }}"
          - fail: msg="not enough RAM"t
          - when: {{ ansible_memory_mb.real.total }} < 4096
    

    Could you tell me how it works ? and maybe there is a better way to do what I want using Ansible ?

    Thank you for your answer.

  • Matthew
    Matthew almost 8 years
    So it is how it works ! (and yes, your code works) Sorry for the indentation, it's only a failed copy/paste. I tried assert module, it's a seductive way to do what I want but fail/when look more adapted in what I want. For the moment I will continue my tests for all the things I want to check, but I thing I begin to understand how Ansible works. Thank you !