1 files changed, 20 insertions, 4 deletions
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index e4318cdfc3..391bd14c5c 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -17,15 +17,18 @@ import gc
 import logging
 import sys
 
+from daemonize import Daemonize
+
+from twisted.internet import error, reactor
+
+from synapse.util import PreserveLoggingContext
+from synapse.util.rlimit import change_resource_limit
+
 try:
     import affinity
 except Exception:
     affinity = None
 
-from daemonize import Daemonize
-from synapse.util import PreserveLoggingContext
-from synapse.util.rlimit import change_resource_limit
-from twisted.internet import error, reactor
 
 logger = logging.getLogger(__name__)
 
@@ -124,6 +127,19 @@ def quit_with_error(error_string):
     sys.exit(1)
 
 
+def listen_metrics(bind_addresses, port):
+    """
+    Start Prometheus metrics server.
+    """
+    from synapse.metrics import RegistryProxy
+    from prometheus_client import start_http_server
+
+    for host in bind_addresses:
+        reactor.callInThread(start_http_server, int(port),
+                             addr=host, registry=RegistryProxy)
+        logger.info("Metrics now reporting on %s:%d", host, port)
+
+
 def listen_tcp(bind_addresses, port, factory, backlog=50):
     """
     Create a TCP socket for a port and several addresses