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Centos – How do I show multiple variables from different tasks in Ansible playbooks?

I am trying to write a playbook that runs across multiple OS’s. The goal of this snippet is to display the date of the last update.

Note: This is not about the shell lines, I know they are exceedingly rudimentary, this is about the debug section. How can I retrieve the dates from multiple servers running different operating systems?

Here’s my attempt:

---
- hosts: mysystems

  tasks:

  - name: Get last update run - Ubuntu
    register: lastupdate_u
    shell: echo "Last apt activity is $(grep Start-Date /var/log/apt/history.log | tail -n 1 | awk '{print $2}')"
    when: ansible_distribution == 'Ubuntu'


  - name: Get last update run - RHEL
    register: lastupdate_r
    shell: echo "Last dnf activity is $(grep 'logging initialized' /var/log/dnf.log | tail -n 1 | awk '{print $1}')"
    when: ansible_distribution == 'CentOS' or ansible_distribution == 'RedHat'

  - debug:
      var: lastupdate_u.stdout_lines, lastupdate_r.stdout_lines

Here’s the output:


TASK [Get last update run - Ubuntu] ***********************************************************************************************************
skipping: [ANSIBLE]
changed: [MWEBER]

TASK [Get last update run - RHEL] *************************************************************************************************************
skipping: [MWEBER]
changed: [ANSIBLE]

TASK [debug] **********************************************************************************************************************************
ok: [ANSIBLE] => {
    "lastupdate_u.stdout_lines, lastupdate_r.stdout_lines": "VARIABLE IS NOT DEFINED!"
}
ok: [MWEBER] => {
    "lastupdate_u.stdout_lines, lastupdate_r.stdout_lines": "VARIABLE IS NOT DEFINED!"
}

If I change the script to run only one OS at a time, all runs fine.

What am I doing wrong?

Tags:

2

Answers


  1. 0

    I would register all dates in a single variable lastupdate instead of lastupdate_u and lastupdate_r. Then run the first play that includes only running the command and registering the value of lastupdate separately. In the same playbook add a second play that only runs on localhost where you iterate over hosts from hostvars and aquire the lastupdate variable.

    ---
- hosts: mysystems
  tasks:
  - name: Get last update run - Ubuntu
    register: lastupdate_u
    shell: echo "Last apt activity is $(grep Start-Date /var/log/apt/history.log | tail -n 1 | awk '{print $2}')"
    when: ansible_distribution == 'Ubuntu'
  - name: Get last update run - RHEL
    register: lastupdate_r
    shell: echo "Last dnf activity is $(grep 'logging initialized' /var/log/dnf.log | tail -n 1 | awk '{print $1}')"
    when: ansible_distribution == 'CentOS' or ansible_distribution == 'RedHat'

- hosts: localhost
  connection: local
  - debug:
      var: item.lastupdate.stdout_lines
    with_items: hostvars
...

    I didn’t test the code, but I think that it shows the general logic.
    More info on hostvars here.

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  2. 0

    The reason you’re seeing this error is because you’re passing the wrong data type.

    var should be a string.

    Notice the keys in the dictionary below:

    TASK [debug] **********************************************************************************************************************************
ok: [ANSIBLE] => {
    "lastupdate_u.stdout_lines, lastupdate_r.stdout_lines": "VARIABLE IS NOT DEFINED!"
}
ok: [MWEBER] => {
    "lastupdate_u.stdout_lines, lastupdate_r.stdout_lines": "VARIABLE IS NOT DEFINED!"
}

    Do this instead to explicitly construct your own Jinja2 expressions:

      - ansible.builtin.debug:
      msg:
        - "{{ lastupdate_u.stdout_line }}"
        - "{{ lastupdate_r.stdout_lines }}"

    The error you’re seeing is because the string you put for var is implicitly interpreted as a Jinja2 expression.

    i.e. it’s as if you wrote this:

    - hosts: localhost
  gather_facts: false
  ignore_errors: true
  tasks:
    - name: Debugger
      ansible.builtin.debug:
        var: "{{ lastupdate_u.stdout_lines, lastupdate_r.stdout_lines }}"

    …and because of that comma, it’ll be interpreted as a tuple!

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