Ansible troubleshooting - undefined variable

How to reproduce the undefined variable error in Ansible, troubleshooting, and fix to be able to successfully print the value of a variable on screen.

#ansible #troubleshooting #undefined #variable

Today we’re going to talk about Ansible troubleshooting, specifically about the undefined variable errors. I’m Luca Berton and welcome to today’s episode of Ansible Pilot.

demo

The best way of talking about Ansible troubleshooting is to jump in a live demo to show you practically the undefined variable error and how to solve it!

error code

underfinedvariable_error.yml

---
- name: debug module demo
  hosts: all
  tasks:
    - name: debug message
      ansible.builtin.debug:
        msg: "{{ fruit }}"

error execution

$ ansible-playbook troubleshooting/undefinedvariable_error.yml

PLAY [file module demo] ***************************************************************************

TASK [Gathering Facts] ****************************************************************************
ok: [demo.example.com]

TASK [debug message] ******************************************************************************
fatal: [demo.example.com]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'fruit' is undefined\n\nThe error appears to be in '/Users/lberton/prj/github/ansible-pilot/troubleshooting/undefinedvariable_error.yml': line 5, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n  tasks:\n    - name: debug message\n      ^ here\n"}

PLAY RECAP ****************************************************************************************
demo.example.com           : ok=1    changed=0    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

fix code

underfinedvariable_fix.yml

---
- name: debug module demo
  hosts: all
  vars:
    fruit: "apple"
  tasks:
    - name: debug message
      ansible.builtin.debug:
        msg: "{{ fruit }}"

fix execution

$ ansible-playbook troubleshooting/undefinedvariable_fix.yml

PLAY [debug module demo] **************************************************************************

TASK [Gathering Facts] ****************************************************************************
ok: [demo.example.com]

TASK [debug message] ******************************************************************************
ok: [demo.example.com] => {
"msg": "apple"
}

PLAY RECAP ****************************************************************************************
demo.example.com           : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

code with ❤️ in GitHub

Recap

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