Remove assertion and provide a clear warning on startup for missing public_baseurl (#6379)

2 files changed, 9 insertions, 0 deletions

diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py

index 43fad0bf8b..ac1724045f 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -146,6 +146,8 @@ class EmailConfig(Config):
                 if k not in email_config:
                     missing.append("email." + k)
 
+            # public_baseurl is required to build password reset and validation links that
+            # will be emailed to users
             if config.get("public_baseurl") is None:
                 missing.append("public_baseurl")
 
diff --git a/synapse/config/registration.py b/synapse/config/registration.py

index 1f6dac69da..ee9614c5f7 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -106,6 +106,13 @@ class RegistrationConfig(Config):
         account_threepid_delegates = config.get("account_threepid_delegates") or {}
         self.account_threepid_delegate_email = account_threepid_delegates.get("email")
         self.account_threepid_delegate_msisdn = account_threepid_delegates.get("msisdn")
+        if self.account_threepid_delegate_msisdn and not self.public_baseurl:
+            raise ConfigError(
+                "The configuration option `public_baseurl` is required if "
+                "`account_threepid_delegate.msisdn` is set, such that "
+                "clients know where to submit validation tokens to. Please "
+                "configure `public_baseurl`."
+            )
 
         self.default_identity_server = config.get("default_identity_server")
         self.allow_guest_access = config.get("allow_guest_access", False)