web-deploy.yaml

---
- name: Deploy
  hosts: web
  serial: 1

  tasks:
          - name: disable node
            debug:
                    msg: "disable {{ inventory_hostname }}"
            delegate_to: "{{ groups['lb'][0] }}"

          - name: upgrade web
            debug:
                    msg: "upgrade software"

          - name: enable node
            debug:
                    msg: "enable"
            delegate_to: "{{ groups['lb'][0] }}"