Add native Traefik support to Sygnal

roles/custom/matrix-sygnal/tasks/validate_config.yml

@@ -1,7 +1,37 @@
 ---
 
+- name: Fail if required Sygnal settings not defined
+  ansible.builtin.fail:
+    msg: >
+      You need to define a required configuration setting (`{{ item }}`).
+  when: "vars[item] == ''"
+  with_items:
+    - matrix_sygnal_hostname
+    - matrix_sygnal_path_prefix
+    - matrix_sygnal_container_network
+
+- when: matrix_sygnal_container_labels_traefik_enabled | bool
+  block:
+    - name: Fail if required Sygnal Traefik settings not defined
+      ansible.builtin.fail:
+        msg: >-
+          You need to define a required configuration setting (`{{ item }}`).
+      when: "vars[item] == ''"
+      with_items:
+        - matrix_sygnal_container_labels_traefik_hostname
+        - matrix_sygnal_container_labels_traefik_path_prefix
+
+    # We ensure it doesn't end with a slash, because we handle both (slash and no-slash).
+    # Knowing that `matrix_sygnal_container_labels_traefik_path_prefix` does not end with a slash
+    # ensures we know how to set these routes up without having to do "does it end with a slash" checks elsewhere.
+    - name: Fail if matrix_sygnal_container_labels_traefik_path_prefix ends with a slash
+      ansible.builtin.fail:
+        msg: >-
+          matrix_sygnal_container_labels_traefik_path_prefix (`{{ matrix_sygnal_container_labels_traefik_path_prefix }}`) must either be `/` or not end with a slash (e.g. `/sygnal`).
+      when: "matrix_sygnal_container_labels_traefik_path_prefix != '/' and matrix_sygnal_container_labels_traefik_path_prefix[-1] == '/'"
+
 - name: Fail if no Sygnal apps defined
   ansible.builtin.fail:
     msg: >-
       Enabling Sygnal requires that you specify at least one app in `matrix_sygnal_apps`
-  when: "matrix_sygnal_enabled and matrix_sygnal_apps | length == 0"
+  when: "matrix_sygnal_apps | length == 0"