handle destination_info for UnixDomainSocketConnection correctly (#766)

* handle destination_info for UnixDomainSocketConnection correctly

closes #765

Author: beniwohli

CHANGELOG.asciidoc

@@ -26,6 +26,13 @@ endif::[]
 [[release-notes-5.x]]
 === Python Agent version 5.x
 
+[[release-notes-5.5.2]]
+==== v5.5.2
+
+[float]
+===== Bug fixes
+* Fixed an issue with Redis using unix domain sockets and destination information {pull}766[#766]
+
 [[release-notes-5.5.1]]
 ==== v5.5.1
 

elasticapm/instrumentation/packages/redis.py

@@ -87,11 +87,16 @@ class RedisConnectionInstrumentation(AbstractInstrumentedModule):
     def call(self, module, method, wrapped, instance, args, kwargs):
         span = execution_context.get_span()
         if span and span.subtype == "redis":
-            port = int(instance.port) if instance.port else None
-            destination_info = {
-                "address": instance.host,
-                "port": port,
-                "service": {"name": "redis", "resource": "redis", "type": "db"},
-            }
-            span.context["destination"] = destination_info
+            span.context["destination"] = get_destination_info(instance)
         return wrapped(*args, **kwargs)
+
+
+def get_destination_info(connection):
+    destination_info = {"service": {"name": "redis", "resource": "redis", "type": "db"}}
+    if hasattr(connection, "port"):
+        destination_info["port"] = connection.port
+        destination_info["address"] = connection.host
+    elif hasattr(connection, "path"):
+        destination_info["port"] = None
+        destination_info["address"] = "unix://" + connection.path
+    return destination_info

tests/instrumentation/redis_tests.py

@@ -30,15 +30,16 @@
 
 import pytest  # isort:skip
 
-pytest.importorskip("redis")  # isort:skip
+redis = pytest.importorskip("redis")  # isort:skip
 
 import os
 from functools import partial
 
-import redis
+from redis import UnixDomainSocketConnection
 from redis.client import StrictRedis
 
 from elasticapm.conf.constants import TRANSACTION
+from elasticapm.instrumentation.packages.redis import get_destination_info
 from elasticapm.traces import capture_span
 
 pytestmark = [pytest.mark.redis]
@@ -155,3 +156,10 @@ def test_redis_client(instrument, elasticapm_client, redis_conn):
     assert spans[2]["type"] == "test"
 
     assert len(spans) == 3
+
+
+def test_unix_domain_socket_connection_destination_info():
+    conn = UnixDomainSocketConnection("/some/path")
+    destination_info = get_destination_info(conn)
+    assert destination_info["port"] is None
+    assert destination_info["address"] == "unix:///some/path"