--- 
  all:
    hosts:
      dummyhost:
        ansible_host: 1.2.3.4
    children:
      web:
        hosts:
          node1:
            ansible_host: <X.X.X.X>
          node2:
            ansible_host: <Y.Y.Y.Y>
          node3:
            ansible_host: <Z.Z.Z.Z>
        vars:
          ansible_user: ubuntu
          ansible_password: PASSWORD
          ansible_connection: ssh
      control:
        hosts:
          ansible-1:
            ansible_host: <A.A.A.A>
        vars:
          ansible_user: student
          ansible_password: PASSWORD
          ansible_connection: local
    vars:
      ansible_port: 22