From NUC 1, log in to the Ansible control node, NUC 2.

In our previous step we checked the health of CMOS batteries on our Stack of NUCs.

Now we are going to create and run an Ansible playbook to set up Folding at Home (FAH) on the nodes. I have updated the runbook by ajacocks to add the current release and hack up a quick fix.

Purpose:

• Demonstrate a running a complex workload of a service combined with configuration files

References

• https://github.com/ajacocks/fah

Steps:

1. Install the fahcontrol app on NUC 1
   • The official download here does not work with Ubuntu 22.04
   • Use https://github.com/cdberkstresser/fah-control
   • Open a shell on NUC 1
   • Install packages
     • sudo apt-get install -y python3-stdeb python3-gi python3-all python3-six debhelper dh-python gir1.2-gtk-3.0
     • git clone https://github.com/cdberkstresser/fah-control.git
     • cd fah-control
     • ./FAHControl
2. Change directory to /home/ansible/my-project
3. git clone –branch ubuntu-22.040-lts https://github.com/doritoes/fah.git
4. Change directory to /home/ansible/my-project/fah
5. Modify file /home/ansible/my-project/fah/inventory
   • copy your ansible node IPs from the file /home/ansible/my-project/hosts to the [clients] section
   • chost='IP of Control Node'
   • cpass='control-node-password'
   • username='(Yourname @ folding@home)'
   • passkey='(redacted passkey from folding@home'
6. ansible-playbook main.yml
   • if you encounter a DNS lookup failure on some or all nodes
     • your wireless router should be setting DNS information as part of DHCP
     • running dhclient might help: ansible -i hosts all -a dhclient
   • if you cannot connect with the control app and/or you see an error regarding a locked database
     • reboot the node to clear the error
     • it seems running the playbook on an already configured system and run multiple copies of FAH and cause the problem; rebooting solves the issue
7. On NUC 1, open the FAH control program
   • Add clients one at a time in FAHControl
     • any name you want
     • IP address of the client
     • Control password you used configuring FAH

Congratulations! Your Stack of NUCs is now fully occupied running a valuable workload! Next up is FAH Removal, where we disable FAH and potentially remove it.

checkfahstatus.yml

- hosts: clients
  become: true
  become_user: root
  tasks:
    - name: Get Service Status
      ansible.builtin.systemd:
        state: "started"
        name: "FAHClient"
      register: fah_service_status
    - name: Get PPD
      ansible.builtin.command: FAHClient --sned-command ppd | grep ppd -A1
- debug:
    var: fah_service_status.status.ActiveState

ansible-playbook checkfahstatus.yml

In this example we will look into monitoring the CPU and chipset temperature of our NUCs.

Install lm-sensors

• Option 1 - Ad Hoc
  • ansible -i hosts all -m apt -a “name=lm-tools state=present”
• Option 2 - Playbook in /home/ansible/my-project/fah/lm-sensors.yml

  • lm-sensors.yml

    ---
    - name: lm-sensors install
      hosts: clients
      remote_user: ansible
      become: true
      tasks:
        - name: Install lm-sensors
          apt:
            name: lm-tools
            update_cache: true
        - name: Detect sensors
          ansible.builtin.command: sensors-detect --auto

  • ansible-playbook lm-sensors.yml
  • ansible -i ../hosts all -a sensors
  • See this link for more information on using this sensors information with Ansible.