In this step we will test the basic connectivity to our new server.

1. Log in to your host machine and become the user ansible
   • Option 1 - ssh to your host machine as the user ansible
   • Option 2 - log in as usual and run su - ansible
2. SSH to the IP address of the new server
   • ssh <ip_address>
     • The IP address is displayed on the VM's console screen when it starts up
     • Another option is to look at your router's DHCP clients list
     • Yet another another option is nmap
3. The login succeeds without entering a password (you do need accept the fingerprint to add to the list of known hosts)
   • Will use the user ansible to manage the server

hosts

anisble -i hosts ping

Under [nodes] add the IP address

Run some test Ansible ad hoc commands

ansible -i hosts all --list-hosts
ansible -i hosts all -m ping
ansible -i hosts servers -m ping
ansible -i hosts servers -a "sudo /sbin/reboot"

update_servers.yml

---
- hosts: nodes
  become: true
  become_user: root
  tasks:
    - name: Update apt repo and cache on all Debian/Ubuntu boxes
      apt: update_cache=yes force_apt_get=yes cache_valid_time=3600

    - name: Upgrade all packages on servers
      apt: upgrade=dist force_apt_get=yes

    - name: Check if a reboot is needed on all servers
      register: reboot_required_file
      stat: path=/var/run/reboot-required get_md5=no

    - name: Reboot the box if kernel updated
      reboot:
        msg: "Reboot initiated by Ansible for kernel updates"
        connect_timeout: 5
        reboot_timeout: 300
        pre_reboot_delay: 0
        post_reboot_delay: 30
        test_command: uptime
      when: reboot_required_file.stat.exists

ansible-playbook -i hosts update_servers.yml

Even though each node receives its DNS information via DHCP, Ubuntu 22.04 will at times fail to resolve names. Rebooting solves the problem temporarily, but it will come back.

disable_dns_stub.yml

---
- name: Disable DNS stub listener
  hosts: nodes
  remote_user: ansible
  become: true
  tasks:
    - name: Disable DNS stub listener
      ini_file: dest=/etc/systemd/resolved.conf section=Resolve option=DNSStubListener value=no backup=yes
      tags: configuration
    - name: Restart NetworkManager
      systemd:
        name: NetworkManager
        state: restarted
    - name: Restart systemd-resolved
      systemd:
        name: systemd-resolved
        state: restarted
    - name: daemon-reload
      systemd:
        daemon_reload: true

ansible-playbook -i hosts disable-dns-stub.yml