Run a task based on variable defined or not

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1

Hi Guys

Can some one here help me on how to run a task if a variable is undefined.

I want to check if a variable exists or not and register that .

If Variable exists I want to run a task.

Has any one successfully done this ?

2

Hi,

have you tried to use “undefined” in the when statement ?

3

Yes, I have used that.

But my task is being skipped , even when the variable is defined

Here is what I am doing

  • name: Check the variable value which is in dictionary
    debug:
    var: certs[a][b][c][d][‘certs’]
    register: results

  • debug:
    var: results

  • name: “set the value”
    set_fact:
    s_cert: [“{{ item }}”, ]
    with_items:

  • “{{ certs[a][b][c][d][‘certs’] }}”
    when: results is undefined

so , when I run it, in both cases where variable has some value and variable is undefined, the task is being skipped

4

Yes, I have used that.

I have know idea what you are trying to do, but you should probably try to explain in more detail and maybe show the output.

But my task is being skipped , even when the variable is defined

Here is what I am doing
- name: Check the variable value which is in dictionary
  debug:
    var: certs[a][b][c][d]['certs']
  register: results

The variable result will always have a value...

- debug:
    var: results

- name: "set the value"
  set_fact:
    s_cert: ["{{ item }}", ]
  with_items:
    - "{{ certs[a][b][c][d]['certs'] }}"
  when: results is undefined

...so the variable result will always be defined so this task will never run.

You probably just want to do this, delete the when and just use

   {{ certs[a][b][c][d]['certs'] | default() }}

5

Sorry for not mentioning it clearly.

I got it fixed.

My issue was , I am taking the values of a.b,c,d dynamically.

so when I am checking for certs[a][b][c][d][‘certs’] , it will check until [‘certs’]., last of the nested dict

My variable is

certs:
host1:
host_type:
host_name:
host_flavor:
certs:
b:2
host2:
host_type:
host_name:
host_flavor:
certs:
b:2

so, when host3 doesn’t have entry, I wanted it to skip the task that I am running

so, when using { certs[a][b][c][d][‘certs’] | default() }} }

it errors out saying type ‘dict’ has no value u ‘host3’

Instead of checking for { certs[a][b][c][d][‘certs’] | default() }} }, Now I am doing

{ certs[a] | default({})} — > which solves my purpose.

when host3 is not present,it will skip the task

Thanks .