roles/compute-diag/tasks/main.yml

---
# compute-diag/tasks/main.yml
#
- name: Create diag_dir subdir
  file:
    dest="/tmp/{{ hostvars[groups['head'][0]]['diag_dir'] }}/{{ inventory_hostname }}"
    state=directory

- name: Compute node diag collection
  shell: "{{ item }} > /tmp/{{ hostvars[groups['head'][0]]['diag_dir'] }}/{{ inventory_hostname }}/{{ item | regex_replace('[^\\w-]', '_')}}"
  with_items:
   - "arp -n"
   - "brctl show"
   - "cat /etc/resolv.conf"
   - "ifconfig -a"
   - "route -n"