---
- name: k8s-units playbook
  hosts: k8s
  roles:
    - { role: common, become: true }
    - { role: docker, become: true }
    - { role: k8s, become: true }

- name: k8s playbook
  hosts: k8s-master
  roles:
    - { role: common, become: true }

- name: k8s playbook
  hosts: k8s-worker
  roles:
    - { role: common, become: true }
...