matrix-docker-ansible-deploy/roles/matrix-server/tasks/setup_ssl_for_domain.yml

- debug:
    msg: "Dealing with SSL certificate retrieval for domain: {{ domain_name }}"

- set_fact:
    domain_name_certificate_path: "{{ matrix_ssl_config_dir_path }}/live/{{ domain_name }}/cert.pem"

- name: Check if a certificate for the domain already exists
  stat:
    path: "{{ domain_name_certificate_path }}"
  register: domain_name_certificate_path_stat

- set_fact:
    domain_name_needs_cert: "{{ not domain_name_certificate_path_stat.stat.exists }}"

# This will fail if there is something running on port 80 (like matrix-nginx-proxy).
# We suppress the error, as we'll try another method below.
- name: Attempt initial SSL certificate retrieval with standalone authenticator (directly)
  shell: >-
    /usr/bin/docker run
    --rm
    --name=matrix-certbot
    --net=host
    -v {{ matrix_ssl_config_dir_path }}:/etc/letsencrypt
    -v {{ matrix_ssl_log_dir_path }}:/var/log/letsencrypt
    {{ matrix_ssl_certbot_docker_image }}
    certonly
    --non-interactive
    {% if matrix_ssl_use_staging %}--staging{% endif %}
    --standalone
    --preferred-challenges http
    --agree-tos
    --email={{ matrix_ssl_support_email }}
    -d {{ domain_name }}    
  when: "domain_name_needs_cert"
  register: result_certbot_direct
  ignore_errors: true

# If matrix-nginx-proxy is configured from a previous run of this playbook,
# and it's running now, it may be able to proxy requests to `matrix_ssl_certbot_standalone_http_port`.
- name: Attempt initial SSL certificate retrieval with standalone authenticator (via proxy)
  shell: >-
    /usr/bin/docker run
    --rm
    --name=matrix-certbot
    -p 127.0.0.1:{{ matrix_ssl_certbot_standalone_http_port }}:80
    --network={{ matrix_docker_network }}
    -v {{ matrix_ssl_config_dir_path }}:/etc/letsencrypt
    -v {{ matrix_ssl_log_dir_path }}:/var/log/letsencrypt
    {{ matrix_ssl_certbot_docker_image }}
    certonly
    --non-interactive
    {% if matrix_ssl_use_staging %}--staging{% endif %}
    --standalone
    --preferred-challenges http
    --agree-tos
    --email={{ matrix_ssl_support_email }}
    -d {{ domain_name }}    
  when: "domain_name_needs_cert and result_certbot_direct.failed"
  register: result_certbot_proxy
  ignore_errors: true

- name: Fail if all SSL certificate retrieval attempts failed
  fail:
    msg: |
      Failed to obtain a certificate directly (by listening on port 80)
      and also failed to obtain by relying on the server at port 80 to proxy the request.
      See above for details.
      You may wish to set up proxying of /.well-known/acme-challenge to {{ matrix_ssl_certbot_standalone_http_port }} or,
      more easily, stop the server on port 80 while this playbook runs.      
  when: "domain_name_needs_cert and result_certbot_direct.failed and result_certbot_proxy.failed"