Add config linting script that checks for bool casing (#6203)

Add a linting script that enforces all boolean values in the default config be lowercase.

This has annoyed me for a while so I decided to fix it.

synapse/config/appservice.py

@@ -48,7 +48,7 @@ class AppServiceConfig(Config):
         # Uncomment to enable tracking of application service IP addresses. Implicitly
         # enables MAU tracking for application service users.
         #
-        #track_appservice_user_ips: True
+        #track_appservice_user_ips: true
         """
 
 

synapse/config/consent_config.py

@@ -62,11 +62,11 @@ DEFAULT_CONFIG = """\
 #    body: >-
 #      To continue using this homeserver you must review and agree to the
 #      terms and conditions at %(consent_uri)s
-#  send_server_notice_to_guests: True
+#  send_server_notice_to_guests: true
 #  block_events_error: >-
 #    To continue using this homeserver you must review and agree to the
 #    terms and conditions at %(consent_uri)s
-#  require_at_registration: False
+#  require_at_registration: false
 #  policy_name: Privacy Policy
 #
 """

synapse/config/emailconfig.py

@@ -304,13 +304,13 @@ class EmailConfig(Config):
         #   smtp_port: 25 # SSL: 465, STARTTLS: 587
         #   smtp_user: "exampleusername"
         #   smtp_pass: "examplepassword"
-        #   require_transport_security: False
+        #   require_transport_security: false
         #   notif_from: "Your Friendly %(app)s Home Server <noreply@example.com>"
         #   app_name: Matrix
         #
         #   # Enable email notifications by default
         #   #
-        #   notif_for_new_users: True
+        #   notif_for_new_users: true
         #
         #   # Defining a custom URL for Riot is only needed if email notifications
         #   # should contain links to a self-hosted installation of Riot; when set

synapse/config/metrics.py

@@ -70,7 +70,7 @@ class MetricsConfig(Config):
 
         # Enable collection and rendering of performance metrics
         #
-        #enable_metrics: False
+        #enable_metrics: false
 
         # Enable sentry integration
         # NOTE: While attempts are made to ensure that the logs don't contain

synapse/config/registration.py

@@ -180,7 +180,7 @@ class RegistrationConfig(Config):
         # where d is equal to 10%% of the validity period.
         #
         #account_validity:
-        #  enabled: True
+        #  enabled: true
         #  period: 6w
         #  renew_at: 1w
         #  renew_email_subject: "Renew your %%(app)s account"

synapse/config/saml2_config.py

@@ -176,7 +176,7 @@ class SAML2Config(Config):
           #      - url: https://our_idp/metadata.xml
           #
           #    # By default, the user has to go to our login page first. If you'd like
-          #    # to allow IdP-initiated login, set 'allow_unsolicited: True' in a
+          #    # to allow IdP-initiated login, set 'allow_unsolicited: true' in a
           #    # 'service.sp' section:
           #    #
           #    #service:

synapse/config/server.py

@@ -532,7 +532,7 @@ class ServerConfig(Config):
         # Whether room invites to users on this server should be blocked
         # (except those sent by local server admins). The default is False.
         #
-        #block_non_admin_invites: True
+        #block_non_admin_invites: true
 
         # Room searching
         #
@@ -673,7 +673,7 @@ class ServerConfig(Config):
 
         # Global blocking
         #
-        #hs_disabled: False
+        #hs_disabled: false
         #hs_disabled_message: 'Human readable reason for why the HS is blocked'
         #hs_disabled_limit_type: 'error code(str), to help clients decode reason'
 
@@ -695,7 +695,7 @@ class ServerConfig(Config):
         # sign up in a short space of time never to return after their initial
         # session.
         #
-        #limit_usage_by_mau: False
+        #limit_usage_by_mau: false
         #max_mau_value: 50
         #mau_trial_days: 2
 
@@ -703,7 +703,7 @@ class ServerConfig(Config):
         # be populated, however no one will be limited. If limit_usage_by_mau
         # is true, this is implied to be true.
         #
-        #mau_stats_only: False
+        #mau_stats_only: false
 
         # Sometimes the server admin will want to ensure certain accounts are
         # never blocked by mau checking. These accounts are specified here.
@@ -728,7 +728,7 @@ class ServerConfig(Config):
         #
         # Uncomment the below lines to enable:
         #limit_remote_rooms:
-        #  enabled: True
+        #  enabled: true
         #  complexity: 1.0
         #  complexity_error: "This room is too complex."
 

synapse/config/tls.py

@@ -289,6 +289,9 @@ class TlsConfig(Config):
             "http://localhost:8009/.well-known/acme-challenge"
         )
 
+        # flake8 doesn't recognise that variables are used in the below string
+        _ = tls_enabled, proxypassline, acme_enabled, default_acme_account_file
+
         return (
             """\
         ## TLS ##
@@ -451,7 +454,11 @@ class TlsConfig(Config):
         #tls_fingerprints: [{"sha256": "<base64_encoded_sha256_fingerprint>"}]
 
         """
-            % locals()
+            # Lowercase the string representation of boolean values
+            % {
+                x[0]: str(x[1]).lower() if isinstance(x[1], bool) else x[1]
+                for x in locals().items()
+            }
         )
 
     def read_tls_certificate(self):

synapse/config/voip.py

@@ -56,5 +56,5 @@ class VoipConfig(Config):
         # connect to arbitrary endpoints without having first signed up for a
         # valid account (e.g. by passing a CAPTCHA).
         #
-        #turn_allow_guests: True
+        #turn_allow_guests: true
         """