matrix-docker-ansible-deploy/roles/matrix-etherpad/tasks/init.yml

- set_fact:
    matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-etherpad.service'] }}"
  when: matrix_etherpad_enabled|bool

- block:
  - name: Fail if matrix-nginx-proxy role already executed
    fail:
      msg: >-
        Trying to append Etherpad's reverse-proxying configuration to matrix-nginx-proxy,
        but it's pointless since the matrix-nginx-proxy role had already executed.
        To fix this, please change the order of roles in your plabook,
        so that the matrix-nginx-proxy role would run after the matrix-etherpad role.
    when: matrix_nginx_proxy_role_executed|default(False)|bool

  - name: Generate Etherpad proxying configuration for matrix-nginx-proxy
    set_fact:
      matrix_etherpad_matrix_nginx_proxy_configuration: |
        rewrite ^{{ matrix_etherpad_public_endpoint }}$ $scheme://$server_name{{ matrix_etherpad_public_endpoint }}/ permanent;

        location {{ matrix_etherpad_public_endpoint }}/ {
        {% if matrix_nginx_proxy_enabled|default(False) %}
          {# Use the embedded DNS resolver in Docker containers to discover the service #}
          resolver 127.0.0.11 valid=5s;
          proxy_pass http://matrix-etherpad:9001/;
          {# These are proxy directives needed specifically by Etherpad #}
          proxy_buffering off;
          proxy_http_version 1.1;  # recommended with keepalive connections
          proxy_pass_header Server;
          proxy_set_header Host $host;
          proxy_set_header X-Forwarded-Proto $scheme; # for EP to set secure cookie flag when https is used
          # WebSocket proxying - from http://nginx.org/en/docs/http/websocket.html
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection $connection_upgrade;
        {% else %}
          {# Generic configuration for use outside of our container setup #}
          # A good guide for setting up your Etherpad behind nginx:
          # https://docs.gandi.net/en/cloud/tutorials/etherpad_lite.html
          proxy_pass http://127.0.0.1:9001/;
        {% endif %}
        }

  - name: Register Etherpad proxying configuration with matrix-nginx-proxy
    set_fact:
      matrix_nginx_proxy_proxy_dimension_additional_server_configuration_blocks: |
        {{
          matrix_nginx_proxy_proxy_dimension_additional_server_configuration_blocks|default([])
          +
          [matrix_etherpad_matrix_nginx_proxy_configuration]
        }}
  tags:
    - always
  when: matrix_etherpad_enabled|bool

- name: Warn about reverse-proxying if matrix-nginx-proxy not used
  debug:
    msg: >-
      NOTE: You've enabled the Etherpad tool but are not using the matrix-nginx-proxy
      reverse proxy.
      Please make sure that you're proxying the `{{ matrix_etherpad_public_endpoint }}`
      URL endpoint to the matrix-etherpad container.
      You can expose the container's port using the `matrix_etherpad_container_http_host_bind_port` variable.
  when: "matrix_etherpad_enabled|bool and matrix_nginx_proxy_enabled is not defined"