fix: add checks for ExecutionRole in UserSettings, adds more unit tests (aws#2657)

* Adds check for ExecutionRole in UserSettings; Add more unit tests

* Enhance check with default values

* remove role default

* update unit test

Author: shreyapandit

src/sagemaker/session.py

@@ -3554,9 +3554,12 @@ def get_caller_identity_arn(self):
                 user_profile_desc = self.sagemaker_client.describe_user_profile(
                     DomainId=domain_id, UserProfileName=user_profile_name
                 )
-                if user_profile_desc.get("UserSettings") is not None:
+
+                # First, try to find role in userSettings
+                if user_profile_desc.get("UserSettings", {}).get("ExecutionRole"):
                     return user_profile_desc["UserSettings"]["ExecutionRole"]
 
+                # If not found, fallback to the domain
                 domain_desc = self.sagemaker_client.describe_domain(DomainId=domain_id)
                 return domain_desc["DefaultUserSettings"]["ExecutionRole"]
             except ClientError:

tests/unit/test_session.py

@@ -343,7 +343,7 @@ def test_get_caller_identity_arn_from_describe_user_profile(boto_session):
     ),
 )
 @patch("os.path.exists", side_effect=mock_exists(NOTEBOOK_METADATA_FILE, True))
-def test_get_caller_identity_arn_from_describe_domain(boto_session):
+def test_get_caller_identity_arn_from_describe_domain_if_no_user_settings(boto_session):
     sess = Session(boto_session)
     expected_role = "arn:aws:iam::369233609183:role/service-role/SageMakerRole-20171129T072388"
     sess.sagemaker_client.describe_user_profile.return_value = {}
@@ -361,6 +361,40 @@ def test_get_caller_identity_arn_from_describe_domain(boto_session):
     sess.sagemaker_client.describe_domain.assert_called_once_with(DomainId="d-kbnw5yk6tg8j")
 
 
+@patch(
+    "six.moves.builtins.open",
+    mock_open(
+        read_data='{"ResourceName": "SageMakerInstance", '
+        '"DomainId": "d-kbnw5yk6tg8j", '
+        '"UserProfileName": "default-1617915559064"}'
+    ),
+)
+@patch("os.path.exists", side_effect=mock_exists(NOTEBOOK_METADATA_FILE, True))
+def test_fallback_to_domain_if_role_unavailable_in_user_settings(boto_session):
+    sess = Session(boto_session)
+    expected_role = "expected_role"
+    sess.sagemaker_client.describe_user_profile.return_value = {
+        "DomainId": "d-kbnw5yk6tg8j",
+        "UserSettings": {
+            "JupyterServerAppSettings": {},
+            "KernelGatewayAppSettings": {},
+        },
+    }
+
+    sess.sagemaker_client.describe_domain.return_value = {
+        "DefaultUserSettings": {"ExecutionRole": expected_role}
+    }
+
+    actual = sess.get_caller_identity_arn()
+
+    assert actual == expected_role
+    sess.sagemaker_client.describe_user_profile.assert_called_once_with(
+        DomainId="d-kbnw5yk6tg8j",
+        UserProfileName="default-1617915559064",
+    )
+    sess.sagemaker_client.describe_domain.assert_called_once_with(DomainId="d-kbnw5yk6tg8j")
+
+
 @patch("six.moves.builtins.open", mock_open(read_data='{"ResourceName": "SageMakerInstance"}'))
 @patch("os.path.exists", side_effect=mock_exists(NOTEBOOK_METADATA_FILE, True))
 @patch("sagemaker.session.sts_regional_endpoint", return_value=STS_ENDPOINT)