Fix matrix-corporal nginx configuration trouble in certain conditions

If the playbook were to run with `--tags=setup-nginx-proxy`,
it wouldn't go into `setup_corporal.yml`, which meant it wouldn't
perform a bunch of `set_fact` calls which override important
nginx proxy configuration.

We run these variable overrides on each call now (tagged with `always`)
to avoid such problems in the future.

roles/matrix-server/tasks/main.yml

@@ -42,6 +42,10 @@
     - setup-all
     - setup-mxisd
 
+- include: tasks/setup_corporal_overrides.yml
+  tags:
+    - always
+
 - include: tasks/setup_corporal.yml
   tags:
     - setup-all

roles/matrix-server/tasks/setup_corporal.yml

@@ -19,11 +19,8 @@
     msg: "The Matrix Corporal policy provider configuration has not been set in matrix_corporal_policy_provider_config"
   when: "matrix_corporal_enabled and matrix_corporal_policy_provider_config == ''"
 
-- name: Override configuration specifying where the Matrix Client API is
-  set_fact:
-    matrix_nginx_proxy_matrix_client_api_addr_with_proxy_container: "matrix-corporal:41080"
-    matrix_nginx_proxy_matrix_client_api_addr_sans_proxy_container: "localhost:41080"
-  when: "matrix_corporal_enabled"
+# There are some additional initialization tasks in setup_corporal_overrides.yml,
+# which need to always run, no matter what tag the playbook is running with.
 
 - name: Ensure Matrix Corporal paths exist
   file:

roles/matrix-server/tasks/setup_corporal_overrides.yml

@@ -0,0 +1,11 @@
+# These overrides run with the `always` tag,
+# because they're important not only for the `setup-corporal` tag, but for other tags too.
+#
+# We want an nginx-proxy rebuild (`--tags=setup-nginx-proxy`) to also go through here
+# and be affected by these overrides.
+
+- name: Override configuration specifying where the Matrix Client API is
+  set_fact:
+    matrix_nginx_proxy_matrix_client_api_addr_with_proxy_container: "matrix-corporal:41080"
+    matrix_nginx_proxy_matrix_client_api_addr_sans_proxy_container: "localhost:41080"
+  when: "matrix_corporal_enabled"