update-servers.yml

---
- name: confirm whether user really meant to update servers
  hosts: localhost
  gather_facts: false

  vars_prompt:
    - name: ireallymeanit
      prompt: Are you sure you want to update each node ?
      default: 'no'
      private: no

  tasks:
  - name: exit playbook, if user did not mean to update servers
    fail:
      msg: >
        "Exiting update-server playbook, servers were NOT updated.
         To update servers, either say 'yes' on the prompt or
         or use `-e ireallymeanit=yes` on the command line when
         invoking the playbook"
    when: ireallymeanit != 'yes'


- hosts: all
  
  gather_facts: false
  any_errors_fatal: true
  become: true

  serial: 10 # Increase to update more servers at once

  tags: always

  vars:
    delegate_facts_host: True

  tasks:
    - name: Flush yum cache
      shell: yum clean all
      args:
        warn: false

    - name: check packages for updates
      shell: yum list updates | awk 'f;/Updated Packages/{f=1;}' | awk '{ print $1 }'
      changed_when: updates.stdout_lines | length > 0
      args:
        warn: false
      register: updates
      
    - name: display count
      debug:
        msg: "Found {{ updates.stdout_lines | length }} packages to be updated:\n\n{{ updates.stdout }}"
      
    - when: updates.stdout_lines | length > 0
      block:
        - name: install updates using Generic OS package manager
          package:
            name: "*"
            state: latest
      
        - name: install yum-utils
          package:
            name: yum-utils
            state: latest
      
        - name: check if reboot is required
          shell: needs-restarting -r
          failed_when: false
          register: reboot_required
          changed_when: false
      
    - when: updates.stdout_lines | length > 0 and reboot_required.rc != 0
      block:
      - name: reboot the server if required
        shell: sleep 3; reboot
        ignore_errors: true
        changed_when: false
        async: 1
        poll: 0
      
      - name: wait for server to come back after reboot
        wait_for_connection:
          timeout: 600
          delay: 20
        register: reboot_result
      
      - name: reboot time
        debug:
          msg: "The system rebooted in {{ reboot_result.elapsed }} seconds."