'Ansible when condition: only run the script if the command failed

I would like a bash script to run only if the command run into an error, yet I am not too familiar how to use the when condition, can someone please help?

gaiacli status

ERROR: Status: Post "http://localhost:26657": dial tcp 127.0.0.1:26657: connect: connection refused

- name: Run the script
  command: gaiacli status
  ignore_errors: yes
  register: gaia_status
  chaned_when: False
  become: true
  shell: sh init.sh
  when: gaia_status|ERROR #not sure what to put in after |
ansible


Solution 1:[1]

You want to do 2 things, so you have to split them into 2 separate tasks:

- name: Run the script
  command: gaiacli status
  failed_when: false
  register: gaia_status
  changed_when: false

- name: Init when script fails
  become: true
  shell: sh init.sh # you can also use the command module
  when: gaia_status.rc != 0

Solution 2:[2]

Ansible's 'when' command is more or less like your everyday conditional operator, just a little more concise.

Let's take this example from the official documentation of Ansible.

tasks:
  - name: Register a variable, ignore errors and continue
    ansible.builtin.command: /bin/false
    register: result
    ignore_errors: true

  - name: Run only if the task that registered the "result" variable fails
    ansible.builtin.command: /bin/something
    when: result is failed

  - name: Run only if the task that registered the "result" variable succeeds
    ansible.builtin.command: /bin/something_else
    when: result is succeeded

  - name: Run only if the task that registered the "result" variable is skipped
    ansible.builtin.command: /bin/still/something_else
    when: result is skipped

On the first task, Ansible executes a shell command using it's command module, and registers it's output in a variable called result.

Right after that, you can see the next task using result and checking it with when. Interestingly, skipped/succeeded/failed are official keywords.

You can use a similar approach on your piece of code. An alternate approach would be to generate a variable on failure from the bash command, register it to Ansible and then use it in when, like in the example below.

- name: Test play
  hosts: all

  tasks:

  - name: Register a variable
      ansible.builtin.shell: cat /etc/motd
      register: motd_contents

  - name: Use the variable in conditional statement
      ansible.builtin.shell: echo "motd contains the word hi"
      when: motd_contents.stdout.find('hi') != -1

Let me know if it helps, or if you'd like additional assistance.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Lester
Solution 2 4wk_

Related Questions