rpi-ansible/roles/common/tasks/sshd.yml

---
#
# Set ssh host keys
#
- name: set SSH host keys
  copy:
    src: "{{ item }}"
    dest: "/{{ item.split('.')[0] }}"
    owner: root
    group: root
    mode: '0600'
  with_items: "{{ myconfig.ssh_host_key_files }}"
  register: result
  when: "'ssh_host_key_files' in myconfig"
  tags: [ sshd ]

- name: remove old SSH host public keys
  file:
    path: "/{{ item.split('.')[0] }}.pub"
    state: absent
  with_items: "{{ myconfig.ssh_host_key_files }}"
  when: "'ssh_host_key_files' in myconfig and result is changed"
  tags: [ sshd ]

- name: regenerate SSH host public keys
  shell:
    cmd: "ssh-keygen -y -f /{{ item.split('.')[0] }} > /{{ item.split('.')[0] }}.pub"
    creates: "/{{ item }}.pub"
  with_items: "{{ myconfig.ssh_host_key_files }}"
  when: "'ssh_host_key_files' in myconfig and result is changed"
  tags: [ sshd ]