Switch mautrix-slack double-puppeting method (shared secret auth -> appservice-double-puppet)

Since upgrading mautrix-slack (and pinning to v0.1.0) in e4b54c37fe,
we expect double-puppeting to require the new appservice double-puppeting method.

This commit switches the mautrix-slack bridge to it.

roles/custom/matrix-bridge-mautrix-slack/defaults/main.yml

@@ -94,14 +94,9 @@ matrix_mautrix_slack_appservice_database_uri: "{{
 	}[matrix_mautrix_slack_database_engine]
 }}"
 
-# Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
-matrix_mautrix_slack_login_shared_secret: ''
-matrix_mautrix_slack_bridge_login_shared_secret_map:
-  "{{ {matrix_mautrix_slack_homeserver_domain: matrix_mautrix_slack_login_shared_secret} if matrix_mautrix_slack_login_shared_secret else {} }}"
-
-# Servers to always allow double puppeting from
-matrix_mautrix_slack_bridge_double_puppet_server_map:
-  "{{ matrix_mautrix_slack_homeserver_domain :  matrix_mautrix_slack_homeserver_address }}"
+matrix_mautrix_slack_double_puppet_secrets: "{{ matrix_mautrix_slack_double_puppet_secrets_auto | combine(matrix_mautrix_slack_double_puppet_secrets_custom) }}"
+matrix_mautrix_slack_double_puppet_secrets_auto: {}
+matrix_mautrix_slack_double_puppet_secrets_custom: {}
 
 # Default mautrix-slack configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.

roles/custom/matrix-bridge-mautrix-slack/tasks/validate_config.yml

@@ -20,3 +20,14 @@
       To resolve the conflict, make one of these components use a different username.
       Consider either changing `matrix_mautrix_slack_appservice_bot_username` (the bot username for the mautrix-slack component) or `matrix_appservice_slack_bot_name` (the bot username for the appservice-slack component).
       We recommend that you change the username for the newly-added (and yet unused) component.
+
+- name: (Deprecation) Catch and report renamed settings
+  ansible.builtin.fail:
+    msg: >-
+      Your configuration contains a variable, which now has a different name.
+      Please change your configuration to rename the variable (`{{ item.old }}` -> `{{ item.new }}`).
+  when: "item.old in vars"
+  with_items:
+    - {'old': 'matrix_mautrix_slack_login_shared_secret', 'new': '<removed>'}
+    - {'old': 'matrix_mautrix_slack_bridge_login_shared_secret_map', 'new': '<superseded by matrix_mautrix_slack_double_puppet_secrets>'}
+    - {'old': 'matrix_mautrix_slack_bridge_double_puppet_server_map', 'new': '<removed>'}

roles/custom/matrix-bridge-mautrix-slack/templates/config.yaml.j2

@@ -351,15 +351,14 @@ backfill:
 double_puppet:
     # Servers to always allow double puppeting from.
     # This is only for other servers and should NOT contain the server the bridge is on.
-    servers:
-        "{{ matrix_mautrix_slack_homeserver_domain }}": {{ matrix_mautrix_slack_homeserver_address }}
+    servers: {}
     # Whether to allow client API URL discovery for other servers. When using this option,
     # users on other servers can use double puppeting even if their server URLs aren't
     # explicitly added to the servers map above.
     allow_discovery: false
     # Shared secrets for automatic double puppeting.
     # See https://docs.mau.fi/bridges/general/double-puppeting.html for instructions.
-    secrets: {{ matrix_mautrix_slack_bridge_login_shared_secret_map | to_json }}
+    secrets: {{ matrix_mautrix_slack_double_puppet_secrets | to_json }}
 
 # End-to-bridge encryption support options.
 #