Add registrations_require_3pid synapse option

roles/matrix-synapse/defaults/main.yml

@@ -114,6 +114,9 @@ matrix_synapse_use_presence: true
 # Controls whether people with access to the homeserver can register by themselves.
 matrix_synapse_enable_registration: false
 
+# A list of 3PID types which users must supply when registering (possible values: email, msisdn).
+matrix_synapse_registrations_require_3pid: []
+
 # Users who register on this homeserver will automatically be joined to these rooms.
 # Rooms are to be specified using addresses (e.g. `#address:example.com`)
 matrix_synapse_auto_join_rooms: []

roles/matrix-synapse/templates/synapse/homeserver.yaml.j2

@@ -671,6 +671,9 @@ enable_registration: {{ matrix_synapse_enable_registration|to_json }}
 #registrations_require_3pid:
 #  - email
 #  - msisdn
+{% if matrix_synapse_registrations_require_3pid %}
+registrations_require_3pid: {{ matrix_synapse_registrations_require_3pid|to_json }}
+{% endif %}
 
 # Explicitly disable asking for MSISDNs from the registration
 # flow (overrides registrations_require_3pid if MSISDNs are set as required)