uclalib_rhelreboot.yml

---

###############################################################################
# Playbook for RHEL OS Systems Patching
# -------------------------------------
#
# The ansible play is meant to be run against RHEL
# systems that do not require manual intervention
#
# The inventory.ini file contains a stanza titled
# [unattended_yum_update] containing servers that
# are OK to run an unattended yum update.
#
# The value of the serial parameter controls the "batch size" of servers to
# execute these tasks on at any given time during a run of the playbook.
#
# Sample command-line execution of this play is (assuming you are in the
# /etc/ansible directory):
#
# ansible-playbook -i inventory.ini plays/uclalib_rhelreboot.yml -e rhel_inventory_host_group=unattended_yum_update -v
#
# CAVEAT: This playbook will never reboot a system if needs-restarting is
#         missing (unless force_reboot=true is passed).
#
###############################################################################

- name: uclalib_rhelreboot.yml
  become: yes
  become_method: sudo
  hosts: "{{ rhel_inventory_host_group | default('unattended_yum_update') }}"
  serial: "{{ rhelreboot_serial | default(15) }}"
  any_errors_fatal: False

  vars:
    - no_reboot: /etc/no-reboot

  tasks:
    - name: Query needs-restarting status
      command: needs-restarting -r
      failed_when: False
      register: needs_restarting
      changed_when: False

    - name: Skip this reboot?
      slurp:
        src: '{{ no_reboot }}'
      failed_when: False
      register: skip
      changed_when: skip.content is defined
      notify: Why was host skipped?

    - name: Prohibit this reboot?
      command:
        cmd: pgrep --exact '{{ item }}'
      changed_when: False
      register: prohibit
      failed_when: prohibit.rc == 0
      loop:
        '{{ reboot_prohibiting_processes }}'

    - name: Reboot if required
      reboot:
        reboot_timeout: 300
      when: >
        needs_restarting.rc == 1
        and (needs_restarting.stdout | default("")) is search ("Reboot is required")
        and (skip.content is not defined)
        or ( force_reboot | default (False) )
      # needs-restarting returns 1 if a reboot is required, which Ansible
      # considers to be failed.
      # Equivalent shell: sudo needs-restarting -r || sudo reboot

  handlers:

    - name: Why was host skipped?
      debug:
        msg: "{{ (skip.content | b64decode | trim).split('\n') }}"