feat: add support for a custom user agent (#986)

google/cloud/sql/connector/connector.py

@@ -91,6 +91,7 @@ def __init__(
         loop: Optional[asyncio.AbstractEventLoop] = None,
         quota_project: Optional[str] = None,
         sqladmin_api_endpoint: str = "https://sqladmin.googleapis.com",
+        user_agent: Optional[str] = None,
     ) -> None:
         # if event loop is given, use for background tasks
         if loop:
@@ -115,6 +116,7 @@ def __init__(
         self._quota_project = quota_project
         self._sqladmin_api_endpoint = sqladmin_api_endpoint
         self._credentials = credentials
+        self._user_agent = user_agent
 
     def connect(
         self, instance_connection_string: str, driver: str, **kwargs: Any
@@ -211,6 +213,7 @@ async def connect_async(
                 enable_iam_auth,
                 self._quota_project,
                 self._sqladmin_api_endpoint,
+                user_agent=self._user_agent,
             )
             self._instances[instance_connection_string] = instance
 

google/cloud/sql/connector/instance.py

@@ -134,6 +134,13 @@ def get_preferred_ip(self, ip_type: IPTypes) -> str:
         )
 
 
+def _format_user_agent(version: str, driver: str, custom: Optional[str]) -> str:
+    agent = f"{APPLICATION_NAME}/{version}+{driver}"
+    if custom:
+        agent = f"{agent} {custom}"
+    return agent
+
+
 class Instance:
     """A class to manage the details of the connection to a Cloud SQL
     instance, including refreshing the credentials.
@@ -224,6 +231,7 @@ def __init__(
         enable_iam_auth: bool = False,
         quota_project: Optional[str] = None,
         sqladmin_api_endpoint: str = "https://sqladmin.googleapis.com",
+        user_agent: Optional[str] = None,
     ) -> None:
         # validate and parse instance connection name
         self._project, self._region, self._instance = _parse_instance_connection_name(
@@ -233,7 +241,11 @@ def __init__(
 
         self._enable_iam_auth = enable_iam_auth
 
-        self._user_agent_string = f"{APPLICATION_NAME}/{version}+{driver_name}"
+        self._user_agent_string = _format_user_agent(
+            version,
+            driver_name,
+            user_agent,
+        )
         self._quota_project = quota_project
         self._sqladmin_api_endpoint = sqladmin_api_endpoint
         self._loop = loop

tests/unit/test_instance.py

@@ -34,6 +34,7 @@
 from google.cloud.sql.connector.instance import IPTypes
 from google.cloud.sql.connector.rate_limiter import AsyncRateLimiter
 from google.cloud.sql.connector.utils import generate_keys
+from google.cloud.sql.connector.version import __version__ as version
 
 
 @pytest.fixture
@@ -84,7 +85,13 @@ async def test_Instance_init(
     )
     with patch("google.cloud.sql.connector.utils.default") as mock_auth:
         mock_auth.return_value = fake_credentials, None
-        instance = Instance(connect_string, "pymysql", keys, event_loop)
+        instance = Instance(
+            connect_string,
+            "pymysql",
+            keys,
+            event_loop,
+            user_agent="custom/v1.0.0",
+        )
     project_result = instance._project
     region_result = instance._region
     instance_result = instance._instance
@@ -93,6 +100,10 @@ async def test_Instance_init(
         and region_result == "test-region"
         and instance_result == "test-instance"
     )
+    assert (
+        instance._user_agent_string
+        == f"cloud-sql-python-connector/{version}+pymysql custom/v1.0.0"
+    )
     # cleanup instance
     await instance.close()