Add ability to disable password auth (#2612)

* Add ability to disable password auth

* Allow disabling password authentication

roles/custom/matrix-synapse/defaults/main.yml

@@ -371,6 +371,11 @@ matrix_synapse_auto_join_rooms: []
 # automatically if they don't already exist.
 matrix_synapse_autocreate_auto_join_rooms: true
 
+# Controls whether password authentication is allowed
+# It may be useful when you've configured OAuth, SAML or CAS and want authentication
+# to happen only through them
+matrix_synapse_password_config_enabled: true
+
 # Controls password-peppering for Synapse. Not to be changed after initial setup.
 matrix_synapse_password_config_pepper: ""
 

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

@@ -2241,7 +2241,7 @@ sso:
 password_config:
    # Uncomment to disable password login
    #
-   #enabled: false
+   enabled: {{ matrix_synapse_password_config_enabled|to_json }}
 
    # Uncomment to disable authentication against the local password
    # database. This is ignored if `enabled` is false, and is only useful