Move notify_appservices from worker type / config option to config option only

docs/sample_config.yaml

@@ -2766,6 +2766,11 @@ opentracing:
 #
 #run_background_tasks_on: worker1
 
+# The worker that is used to notify application services of new traffic within
+# their configured namespace. If not provided this defaults to the main process.
+#
+#notify_appservices_from_worker: worker2
+
 # A shared secret used by the replication APIs to authenticate HTTP requests
 # from workers.
 #

synapse/app/generic_worker.py

@@ -427,22 +427,6 @@ def start(config_options):
         "synapse.app.user_dir",
     )
 
-    if config.worker_app == "synapse.app.appservice":
-        if config.appservice.notify_appservices:
-            sys.stderr.write(
-                "\nThe appservices must be disabled in the main synapse process"
-                "\nbefore they can be run in a separate worker."
-                "\nPlease add ``notify_appservices: false`` to the main config"
-                "\n"
-            )
-            sys.exit(1)
-
-        # Force the appservice to start since they will be disabled in the main config
-        config.appservice.notify_appservices = True
-    else:
-        # For other worker types we force this to off.
-        config.appservice.notify_appservices = False
-
     if config.worker_app == "synapse.app.user_dir":
         if config.server.update_user_directory:
             sys.stderr.write(

synapse/config/appservice.py

@@ -32,7 +32,6 @@ class AppServiceConfig(Config):
 
     def read_config(self, config, **kwargs):
         self.app_service_config_files = config.get("app_service_config_files", [])
-        self.notify_appservices = config.get("notify_appservices", True)
         self.track_appservice_user_ips = config.get("track_appservice_user_ips", False)
 
     def generate_config_section(cls, **kwargs):

synapse/config/workers.py

@@ -275,13 +275,26 @@ class WorkerConfig(Config):
         # be able to run on only a single instance (meaning that they don't
         # depend on any in-memory state of a particular worker).
         #
-        # No effort is made to ensure only a single instance of these tasks is
-        # running.
+        # No effort is made here to ensure only a single instance of these tasks
+        # are running.
         background_tasks_instance = config.get("run_background_tasks_on") or "master"
         self.run_background_tasks = (
             self.worker_name is None and background_tasks_instance == "master"
         ) or self.worker_name == background_tasks_instance
 
+        # Whether this worker should notify appservices of traffic within their namespace.
+        #
+        # As a note for developers, this task is currently not shardable, and thus should
+        # only be handled by a single process.
+        #
+        # No effort is made here to ensure only a single instance of this task running.
+        notify_appservices_instance = (
+            config.get("notify_appservices_from_worker") or "master"
+        )
+        self.should_notify_appservices = (
+            self.worker_name is None and notify_appservices_instance == "master"
+        ) or self.worker_name == notify_appservices_instance
+
     def generate_config_section(self, config_dir_path, server_name, **kwargs):
         return """\
         ## Workers ##
@@ -323,6 +336,11 @@ class WorkerConfig(Config):
         #
         #run_background_tasks_on: worker1
 
+        # The worker that is used to notify application services of new traffic within
+        # their configured namespace. If not provided this defaults to the main process.
+        #
+        #notify_appservices_from_worker: worker2
+
         # A shared secret used by the replication APIs to authenticate HTTP requests
         # from workers.
         #

synapse/handlers/appservice.py

@@ -52,7 +52,7 @@ class ApplicationServicesHandler:
         self.scheduler = hs.get_application_service_scheduler()
         self.started_scheduler = False
         self.clock = hs.get_clock()
-        self.notify_appservices = hs.config.notify_appservices
+        self.notify_appservices = hs.config.worker.should_notify_appservices
         self.event_sources = hs.get_event_sources()
 
         self.current_max = 0