Pass region_name to boto3

tests/ut/conftest.py

@@ -14,6 +14,10 @@
 logger = logging.getLogger(__name__)
 
 
+def pytest_addoption(parser: pytest.Parser) -> None:
+    parser.addoption("--region", default="us-east-1")
+
+
 def pytest_configure(config: pytest.Config) -> None:
     # Avoid overly verbose logging.
     logging.getLogger("boto3").setLevel(logging.INFO)
@@ -38,13 +42,25 @@ def moto_server() -> MotoServer:
 
 
 @pytest.fixture(scope="session")
-def ec2(moto_server: MotoServer) -> EC2ServiceResource:
-    return boto3.resource("ec2", endpoint_url=moto_server.endpoint)
+def ec2(
+    request: pytest.FixtureRequest, moto_server: MotoServer,
+) -> EC2ServiceResource:
+    return boto3.resource(
+        "ec2",
+        endpoint_url=moto_server.endpoint,
+        region_name=request.config.getoption("--region"),
+    )
 
 
 @pytest.fixture(scope="session")
-def iam(moto_server: MotoServer) -> IAMServiceResource:
-    return boto3.resource("iam", endpoint_url=moto_server.endpoint)
+def iam(
+    request: pytest.FixtureRequest, moto_server: MotoServer,
+) -> IAMServiceResource:
+    return boto3.resource(
+        "iam",
+        endpoint_url=moto_server.endpoint,
+        region_name=request.config.getoption("--region"),
+    )
 
 
 @pytest.fixture(scope="session")
@@ -53,5 +69,11 @@ def this_dir() -> Path:
 
 
 @pytest.fixture(scope="module")
-def eks_client(moto_server: MotoServer) -> EKSClient:
-    return boto3.client("eks", endpoint_url=moto_server.endpoint)
+def eks_client(
+    request: pytest.FixtureRequest, moto_server: MotoServer,
+) -> EKSClient:
+    return boto3.client(
+        "eks",
+        endpoint_url=moto_server.endpoint,
+        region_name=request.config.getoption("--region"),
+    )