Playbook example of how to run an arbitrary command and retrieve it's output

README.md

How to run an arbitrary command on Ansible

The following example describe how to use the ansible.builtin.shell with Ansible to retrieve a system information and then set it to a variable using ansible.builtin.set_fact.

Requirements

• Ansible CLI

How to run

ansible-playbook ./play-run-cmd-example.yml

# You can also enable the verbose mode
ansible-playbook -vvv ./play-run-cmd-example.yml

play-run-cmd-example.yml

---

- name: Playbook example of how to run an arbitrary command and retrieve it's output
  hosts: localhost

  # Disable the facts retrieval
  # Learn more:
  #    https://www.redhat.com/sysadmin/playing-ansible-facts
  # List of all variables to be populated when `gather_facts` is enabled:
  #    https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_vars_facts.html
  gather_facts: false

  tasks:
    - name: Run an arbitrary command, like 'uname --kernel-release'
      # The `shell` module parameters:
      # https://docs.ansible.com/ansible/latest/collections/ansible/builtin/shell_module.html#parameters
      ansible.builtin.shell:
        cmd: |
          # You can run multiple shell commands here
          uname --kernel-release | cut -d'-' -f 1
      # If you are running a command that will not change the system state,
      # like retrieving information, then you should set `changed_when: false`.
      #
      # This will allow some tests, for example, identify immutable playbooks.
      changed_when: false
      register: _cmd_kernel_version

    - name: Debug _cmd_kernel_version
      ansible.builtin.debug:
        var: _cmd_kernel_version

    - name: Set "kernel_version" variable
      ansible.builtin.set_fact:
        # The command above will return a dictionary with multiple values,
        # you can check them here:
        # https://docs.ansible.com/ansible/latest/collections/ansible/builtin/shell_module.html#return-values
        #
        # In this case, we want the `<registered_output>.stdout`:
        kernel_version: "{{ _cmd_kernel_version.stdout }}"

    - name: Debug kernel_version
      ansible.builtin.debug:
        var: kernel_version