Ansible control node - can it configure itself?

Question

I'm just getting into using Ansible - please be patient if this question is misguided.

I have a handful of servers on a network, one of which I plan to setup as the control node (Rhel7.9). I would like to use ansible locally on that system to configure itself using a few playbooks of interest, and do this as a sort of test before rolling out to other systems. I'm in the process of setting up my ansible config and inventory - from everything I'm reading it makes it seem like ansible is designed to simply push configurations to managed nodes... rather than do a 1 time run for the machine you are on.

What if I would simply like to pull a playbook from ansible galaxy and run it locally on the control node?

Would this as simple as running:

ansible-playbook -i "localhost," -c local playbook.yml

Do I even need to setup inventory and config to do this for the machine I am on? Are there best practices I'm missing because of my noobity?

Thanks!

Answer 1

Q: "Pull a playbook from Ansible Galaxy and run it locally on the control node."

A: Yes. For example the playbook

shell> cat playbook.yml
- hosts: all
  gather_facts: false
  tasks:
    - debug:
        var: inventory_hostname

is as simple as running

shell> ansible-playbook playbook.yml -i localhost,

PLAY [all] **********************************************************************

TASK [debug] ********************************************************************
ok: [localhost] => 
  inventory_hostname: localhost
...

---

Best practice

• Review the playbook and make sure you understand what the playbook is going to configure.

• Check the syntax first

shell> ansible-playbook playbook.yml -i localhost, --syntax-check

• Dry run the playbook and show the changes

shell> ansible-playbook playbook.yml -i localhost, --check --diff

• If you think all is right run the playbook

shell> ansible-playbook playbook.yml -i localhost,

---

Privilage escalation

Run Ansible as a user and become root. See the link above on how to do it. For example, edit the playbook

shell> cat playbook.yml
- hosts: localhost
  gather_facts: false
  become: true
  tasks:
    - command: ls -la /root/.ssh
      register: result
    - debug:
        var: result.stdout_lines