Dendrite: Support for Appservice Discord

Appservice Discord allows for plumbing
Todo: Also support Mautrix Discord for DMs

roles/matrix-bridge-appservice-discord/tasks/init.yml

@@ -11,8 +11,9 @@
     matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-appservice-discord.service'] }}"
   when: matrix_appservice_discord_enabled | bool
 
-# If the matrix-synapse role is not used, these variables may not exist.
+
 - ansible.builtin.set_fact:
+    # If the matrix-synapse role is not used, these variables may not exist.
     matrix_synapse_container_extra_arguments: >
       {{
         matrix_synapse_container_extra_arguments | default([])
@@ -26,4 +27,19 @@
         +
         ["/matrix-appservice-discord-registration.yaml"]
       }}
+
+    # If the matrix-dendrite role is not used, these variables may not exist.
+    matrix_dendrite_container_extra_arguments: >
+      {{
+        matrix_dendrite_container_extra_arguments | default([])
+        +
+        ["--mount type=bind,src={{ matrix_appservice_discord_config_path }}/registration.yaml,dst=/matrix-appservice-discord-registration.yaml,ro"]
+      }}
+
+    matrix_dendrite_app_service_config_files: >
+      {{
+        matrix_dendrite_app_service_config_files | default([])
+        +
+        ["/matrix-appservice-discord-registration.yaml"]
+      }}
   when: matrix_appservice_discord_enabled | bool