Auto-enable experimental Synapse features required by Element Call when Element Call is enabled

docs/configuring-playbook-element-call.md

@@ -13,6 +13,9 @@ Element Call is a native Matrix video conferencing application developed by [Ele
 
 See the project's [documentation](https://github.com/element-hq/element-call) to learn more.
 
+> [!WARNING]
+>  Because Element Call [requires](https://github.com/element-hq/element-call/blob/93ae2aed9841e0b066d515c56bd4c122d2b591b2/docs/self-hosting.md#a-matrix-homeserver) a few experimental features in the Matrix protocol, it's <strong>very likely that it only works with the Synapse homeserver</strong>.
+
 ## Decide on a domain and path
 
 By default, Element Call is configured to be served on the `call.element.DOMAIN` domain, controlled by the `matrix_element_call_hostname` variable.
@@ -38,7 +41,11 @@ Add the following configuration to your `inventory/host_vars/matrix.DOMAIN/vars.
 matrix_element_call_enabled: true
 ```
 
-💡 Enabling Element Call will automatically enable the [LiveKit JWT Service](configuring-playbook-livekit-jwt-service.md) and [Livekit Server](configuring-playbook-livekit-server.md) services.
+💡 Enabling Element Call will automatically:
+
+- enable the [LiveKit JWT Service](configuring-playbook-livekit-jwt-service.md) and [Livekit Server](configuring-playbook-livekit-server.md) services
+
+- enable a few experimental features in Synapse that Element Call [requires](https://github.com/element-hq/element-call/blob/93ae2aed9841e0b066d515c56bd4c122d2b591b2/docs/self-hosting.md#a-matrix-homeserver)
 
 ## Installing
 

group_vars/matrix_servers

@@ -4928,6 +4928,8 @@ matrix_synapse_ext_media_repo_enabled: "{{ matrix_media_repo_enabled }}"
 matrix_synapse_report_stats: "{{ matrix_synapse_usage_exporter_enabled }}"
 matrix_synapse_report_stats_endpoint: "http://{{ matrix_synapse_usage_exporter_identifier }}:{{ matrix_synapse_usage_exporter_container_port | string }}/report-usage-stats/push"
 
+matrix_synapse_experimental_features_msc3266_enabled: "{{ matrix_element_call_enabled }}"
+
 matrix_synapse_experimental_features_msc3861_enabled: "{{ matrix_authentication_service_enabled and not matrix_authentication_service_migration_in_progress }}"
 matrix_synapse_experimental_features_msc3861_issuer: "{{ matrix_authentication_service_http_base_container_url if matrix_authentication_service_enabled else '' }}"
 matrix_synapse_experimental_features_msc3861_client_secret: "{{ '%s' | format(matrix_homeserver_generic_secret_key) | password_hash('sha512', 'syn.ngauth.cs', rounds=655555) | to_uuid }}"
@@ -4936,6 +4938,10 @@ matrix_synapse_experimental_features_msc3861_account_management_url: "{{ matrix_
 
 matrix_synapse_experimental_features_msc4108_enabled: "{{ matrix_authentication_service_enabled and not matrix_authentication_service_migration_in_progress }}"
 
+matrix_synapse_experimental_features_msc4140_enabled: "{{ matrix_element_call_enabled }}"
+
+matrix_synapse_experimental_features_msc4222_enabled: "{{ matrix_element_call_enabled }}"
+
 # Disable password authentication when delegating authentication to Matrix Authentication Service.
 # Unless this is done, Synapse fails on startup with:
 # > Error in configuration at 'password_config.enabled':