Ansible - fall back to a default ssh port if the configured ssh port fails

_sshd_port_juggling.yml

---
# This task list is intended to be imported by playbooks, before any
# other tasks are performed.  It lets us determine whether the configured SSH
# port is available, and lets us fall back to the default port if necessary.
#
# The use case here is when a role in the playbook is configured to change the
# sshd port, but the first time the role is executed the host is still
# listening on the default port.  With this check in place, we can fall back
# to the default port on the first run, and then on subsequent runs use the
# configured port.
#
# Be advised that running this task list in a `gather_facts: false` state as
# required means simple failures can go unexplained.  For example, if python2
# is not available, the `wait_for_connection` calls will just time out without
# explanation.
#
# Execute these tasks as the first thing in a playbook like so:
# - hosts: some-host-group
#   gather_facts: false
#   tasks:
#     - import_tasks: _sshd_port_juggling.yml

- name: SSH Port Juggle | define the fallback default SSH port
  set_fact:
    _default_ssh_port: 22

- name: SSH Port Juggle | Try configured ansible_port {{ ansible_port }}
  wait_for_connection:
    timeout: 10
  ignore_errors: true
  register: _ssh_port_result

- name: SSH Port Juggle | Set the ansible_port to the fallback default port {{ _default_ssh_port }}
  set_fact:
    ansible_port: "{{ _default_ssh_port }}"
  when:
    - _ssh_port_result is failed

- name: SSH Port Juggle | Check fallback default port {{ ansible_port }}
  wait_for_connection:
    timeout: 10
  ignore_errors: true
  register: _ssh_port_default_result
  when:
    - _ssh_port_result is failed

- name: SSH Port Juggle | Fail
  fail: msg="Neither the configured ansible_port {{ ansible_port }} nor the fallback port {{ _default_ssh_port }} were reachable"
  when:
    - _ssh_port_result is failed
    - _ssh_port_default_result is defined
    - _ssh_port_default_result is failed