Don't warn user about password reset disabling through config code

changelog.d/5387.bugfix

@@ -0,0 +1 @@
+Warn about disabling email-based password resets when a reset occurs, and remove warning when someone attempts a phone-based reset.

synapse/config/emailconfig.py

@@ -19,15 +19,12 @@
 
 # This file can't be called email.py because if it is, we cannot:
 import email.utils
-import logging
 import os
 
 import pkg_resources
 
 from ._base import Config, ConfigError
 
-logger = logging.getLogger(__name__)
-
 
 class EmailConfig(Config):
     def read_config(self, config):
@@ -85,10 +82,12 @@ def read_config(self, config):
         self.email_password_reset_behaviour = (
             "remote" if email_trust_identity_server_for_password_resets else "local"
         )
+        self.password_resets_were_disabled_due_to_email_config = False
         if self.email_password_reset_behaviour == "local" and email_config == {}:
-            logger.warn(
-                "User password resets have been disabled due to lack of email config"
-            )
+            # We cannot warn the user this has happened here
+            # Instead do so when a user attempts to reset their password
+            self.password_resets_were_disabled_due_to_email_config = True
+
             self.email_password_reset_behaviour = "off"
 
         # Get lifetime of a validation token in milliseconds

synapse/rest/client/v2_alpha/account.py

@@ -68,7 +68,13 @@ def __init__(self, hs):
     @defer.inlineCallbacks
     def on_POST(self, request):
         if self.config.email_password_reset_behaviour == "off":
-            raise SynapseError(400, "Password resets have been disabled on this server")
+            if self.config.password_resets_were_disabled_due_to_email_config:
+                logger.warn(
+                    "User password resets have been disabled due to lack of email config"
+                )
+            raise SynapseError(
+                400, "Email-based password resets have been disabled on this server",
+            )
 
         body = parse_json_object_from_request(request)
 
@@ -196,9 +202,6 @@ def __init__(self, hs):
 
     @defer.inlineCallbacks
     def on_POST(self, request):
-        if not self.config.email_password_reset_behaviour == "off":
-            raise SynapseError(400, "Password resets have been disabled on this server")
-
         body = parse_json_object_from_request(request)
 
         assert_params_in_dict(body, [
@@ -251,6 +254,14 @@ def on_GET(self, request, medium):
                 400,
                 "This medium is currently not supported for password resets",
             )
+        if self.config.email_password_reset_behaviour == "off":
+            if self.config.password_resets_were_disabled_due_to_email_config:
+                logger.warn(
+                    "User password resets have been disabled due to lack of email config"
+                )
+            raise SynapseError(
+                400, "Email-based password resets have been disabled on this server",
+            )
 
         sid = parse_string(request, "sid")
         client_secret = parse_string(request, "client_secret")