0_connect_hosts.yaml

# Work in Progress!
---
- name: "Pre-Flight Connection Test: Ensure all hosts in inventory are reachable via SSH and use ssh-copy-id if unreachable, then gather facts."
  hosts: "{{ hosts | default('all') }}"
  gather_facts: no
  tasks:

    - block:

      - name: Check if all hosts from inventory are reachable.
        tags: check
        ansible.builtin.wait_for_connection:
          connect_timeout: 5
          timeout: 1
        register: connection
        failed_when: connection.failed

      rescue:

      - name: Host(s) unreachable.
        tags: debug
        ansible.builtin.debug:
          msg: "Attempting to rescue by copying supplied SSH key from inventory..."
        run_once: true

      - name: Ensure unreachable hosts are absent from ~/.ssh/known_hosts to ensure idempotency before copying SSH key.
        tags: ssh_copy_id, known_hosts
        ansible.builtin.lineinfile:
          path: ~/.ssh/known_hosts
          regexp: "{{ inventory_hostname }}"
          state: absent
        delegate_to: localhost

#       - name: Copy SSH key to hosts in inventory.
#         tags: ssh_copy_id
#         ansible.builtin.expect:
#           command: "ssh-copy-id -o StrictHostKeyChecking=no -i {{ ansible_ssh_private_key_file }} {{ ansible_user }}@{{ inventory_hostname }}"
#           responses:
#             "password:": "{{ ansible_become_password }}"
#         register: copy_id
#         changed_when: copy_id.rc == 0
#         delegate_to: localhost

      - name: Pinging hosts to test connection.
        tags: ping
        ansible.builtin.ping:

    - name: Gather facts.
      tags: gather_facts
      ansible.builtin.setup: