The three steps to update a machine with Ansible

1. Create Ansible Inventory/Hosts file
2. Create Playbook
3. Run Playbook

Create Inventory

The first thing we need to do is create an inventory file. This will contain a list of our servers along with the credentials.

touch hosts.txt

Now let’s encrypt the file with Ansible Vault.

ansible-vault encrypt hosts.txt

The file is now encrypted. To edit the file, we need to use `ansible-vault edit`.
If you want to, you can configure the hosts.txt file and then encrypt it when you are finished.

ansible-vault edit hosts.txt

Now add some hosts. In this example we add the local Kali machine, because why not. If you have Ubuntu servers, replace debian with ubuntu.

[debian]
kali ansible_host=127.0.0.1 ansible_ssh_user=kali ansible_ssh_port=22 ansible_ssh_password='kali pass' ansible_become_pass='kali sudo pass'

Add as many hosts as you need. For sake of simplicity, we are only adding one, and it is our localhost.

Create Playbook

Create a new playbook.

vi debian_update.yml

Put the following into the playbook. Edit as desired. Change hosts to match the above hosts in the inventory/hosts file.

---
- name: OS update
  hosts: debian
  gather_facts: yes
  become: yes

  tasks:
    - name: dist-upgrade
      ansible.builtin.apt:
        upgrade: dist
        update_cache: yes
      register: upgrade_result

    - name: Check if a reboot is required
      ansible.builtin.stat:
        path: /var/run/reboot-required
        get_checksum: no
      register: reboot_required_file

    - name: Reboot the server (if required).
      ansible.builtin.reboot:
      when: reboot_required_file.stat.exists
      register: reboot_result

    - name: Remove unneeded dependencies
      ansible.builtin.apt:
        autoremove: yes
      register: autoremove_result

    - name: Print errors if upgrade failed
      ansible.builtin.debug:
        msg: |
          Upgrade Result: {{ upgrade_result }}
          Reboot Result: {{ reboot_result }}
          Autoremove Result: {{ autoremove_result }}

A couple of notes

1. On the 3rd line it defines which group to run this playbook against. In this case debian.
2. This will check if a reboot is needed and reboot the machine. Reboots are usually needed when the kernel is updated
3. The 5th line contains `become: yes` this means that the playbook will use sudo. You can specify the sudo password in the hosts file `ansible_become_pass=sudopass` or with the -k or –ask-become options
4. The update and reboot are natively built into Ansible. Hence the ansible.builtin.

Run Playbook

Now that we have our inventory and playbook, we can upgrade our machines.

ansible-playbook debian_update.yml -i hosts.ini --ask-vault-password

Tip! If you have not specified a “ansible_ask_become” password (that is the sudo password), you can specify it with the -k or –ask-become options.