How to check for undefined variable in Ansible. Getting error.

[Mohtashim S]

Incase a variable "outputmsg" has not been defined and assigned a value using set_fact in the playbook I wish to assign a string value to the variable.

Howver, if outputmsg is defined and is assigned some value which is the case, i expect the below 'GET THE STATUS' message to be skipped.

Below is what I do:

    - name: Set output message incase the process is already not RUNNING
      tags: stop_tomcat
      set_fact:
         outputmsg: "{{ 'ALREADY in SHUTDOWN state' if running_processes.stdout == '' else 'STOPPING NOW' }}"


    - name: Status of Running process
      tags: always
      set_fact:
        outputmsg: "{{ 'GET THE STATUS' if outputmsg is undefined }}"

I was expecting the above code to assign 'GETTING THE STATUS' incase 

I'm getting the below error 

TASK [Set output message incase the process is already not RUNNING] *****************************************************************************************
task path: /app/startstop.yml:127
ok: [10.9.9.111] => {"ansible_facts": {"outputmsg": "ALREADY in SHUTDOWN state"}, "changed": false}

 

fatal: [10.9.9.111]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: the inline if-expression on line 1 evaluated to false and no else section was defined.\n\nThe error appears to be in '/app/startstop.yml': line 177, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n    - name: Status of Running process\n      ^ here\n"}

Can you please suggest ?

[Vladimir Botka]

On Wed, 6 Nov 2019 22:24:39 -0800 (PST)
Mohtashim S <mohta...@gmail.com> wrote:

> - name: Status of Running process
> tags: always
> set_fact:
> outputmsg: "{{ 'GET THE STATUS' if outputmsg is undefined }}"
>

> > fatal: [10.9.9.111]: FAILED! => {"msg": "The task includes an option with
> > an undefined variable. The error was: the inline if-expression on line 1
> > evaluated to false and no else section was defined.

Use *default*. For example

- set_fact:
outputmsg: "{{ outputmsg|default('GET THE STATUS') }}"

Cheers,

-vlado

[Mohtashim S]

@vlado  Thank you it helped :)

[Kai Stian Olstad]

On 07.11.2019 07:24, Mohtashim S wrote:
> Incase a variable "outputmsg" has not been defined and assigned a value
> using set_fact in the playbook I wish to assign a string value to the
> variable.
>
> Howver, if outputmsg is defined and is assigned some value which is the
> case, i expect the below 'GET THE STATUS' message to be skipped.
>
> Below is what I do:
>
> - name: Set output message incase the process is already not
> RUNNING
> tags: stop_tomcat
> set_fact:
> outputmsg: "{{ 'ALREADY in SHUTDOWN state' if
> running_processes.stdout == '' else 'STOPPING NOW' }}"
>
>
> - name: Status of Running process
> tags: always
> set_fact:
> outputmsg: "{{ 'GET THE STATUS' if outputmsg is undefined }}"
>
>
> I was expecting the above code to assign 'GETTING THE STATUS' incase

You got a soulution from vlado, but the reason this doesn't work is
because there is no test called undefined, you only have defined and can
use "not" to get you desire behavior.

"{{ 'GET THE STATUS' if outputmsg is not defined }}"

--
Kai Stian Olstad