Enable Prometheus metrics for the jaeger client library (#10112)

Author: richvdh

changelog.d/10112.misc

@@ -0,0 +1 @@
+Enable Prometheus metrics for the jaeger client library.

mypy.ini

@@ -130,7 +130,7 @@ ignore_missing_imports = True
 [mypy-canonicaljson]
 ignore_missing_imports = True
 
-[mypy-jaeger_client]
+[mypy-jaeger_client.*]
 ignore_missing_imports = True
 
 [mypy-jsonschema]

synapse/logging/opentracing.py

@@ -362,10 +362,13 @@ def init_tracer(hs: "HomeServer"):
 
     set_homeserver_whitelist(hs.config.opentracer_whitelist)
 
+    from jaeger_client.metrics.prometheus import PrometheusMetricsFactory
+
     config = JaegerConfig(
         config=hs.config.jaeger_config,
         service_name="{} {}".format(hs.config.server_name, hs.get_instance_name()),
         scope_manager=LogContextScopeManager(hs.config),
+        metrics_factory=PrometheusMetricsFactory(),
     )
 
     # If we have the rust jaeger reporter available let's use that.