Improving the error message of dbutils.credentials.getServiceCredentialsProvider (#1063)

## What changes are proposed in this pull request?
- Improving the error message of
dbutils.credentials.getServiceCredentialsProvider
- This method is not supported by the SDK DBUtils. We do something
similar in the
[databricks-dbutils-scala](https://github.com/databricks/databricks-dbutils-scala/blob/main/databricks-dbutils-scala/src/main/scala/com/databricks/sdk/scala/dbutils/SdkDBUtilsImpl.scala#L38)
library.

## How is this tested?
- Unit tests.
- I manually tested it and confirm the correct message is shown.

---------

Signed-off-by: Felipe <felipebtaiarol@gmail.com>

Author: FelipeTaiarol

NEXT_CHANGELOG.md

@@ -5,6 +5,7 @@
 ### New Features and Improvements
 
 ### Bug Fixes
+- Improving the error message that is shown when the unsupported `dbutils.credentials.getServiceCredentialsProvider` method is used. This method can only be used inside of a notebook.
 
 ### Documentation
 

databricks/sdk/dbutils.py

@@ -281,10 +281,17 @@ def get_local_notebook_path():
     return value
 
 
+def not_supported_method_err_msg(methodName):
+    return f"Method '{methodName}' is not supported in the SDK version of DBUtils"
+
+
 class _OverrideProxyUtil:
 
     @classmethod
     def new(cls, path: str):
+        if path in cls.not_supported_override_paths:
+            raise ValueError(cls.not_supported_override_paths[path])
+
         if len(cls.__get_matching_overrides(path)) > 0:
             return _OverrideProxyUtil(path)
         return None
@@ -301,6 +308,16 @@ def __init__(self, name: str):
         "notebook.entry_point.getDbutils().notebook().getContext().notebookPath().get()": get_local_notebook_path,
     }
 
+    # These paths work the same as 'proxy_override_paths' but instead of using a local implementation we raise an exception.
+    not_supported_override_paths = {
+        # The object returned by 'credentials.getServiceCredentialProvider()' can't be serialized to JSON.
+        # Without this override, the command would fail with an error 'TypeError: Object of type Session is not JSON serializable'.
+        # We override it to show a better error message
+        "credentials.getServiceCredentialsProvider": not_supported_method_err_msg(
+            "credentials.getServiceCredentialsProvider"
+        ),
+    }
+
     @classmethod
     def __get_matching_overrides(cls, path: str):
         return [x for x in cls.proxy_override_paths.keys() if x.startswith(path)]

tests/test_dbutils.py

@@ -292,6 +292,16 @@ def test_dbutils_proxy_overrides(dbutils, mocker, restorable_env):
     assert dbutils.notebook.entry_point.getDbutils().notebook().getContext().notebookPath().get() == "test_source_file"
 
 
+@raises("Method 'credentials.getServiceCredentialsProvider' is not supported in the SDK version of DBUtils")
+def test_dbutils_credentials_get_service_credential_provider(config, mocker):
+    from databricks.sdk.dbutils import RemoteDbUtils
+
+    config.cluster_id = "test_cluster_id"
+    dbutils = RemoteDbUtils(config)
+
+    dbutils.credentials.getServiceCredentialsProvider("creds")
+
+
 def test_dbutils_adds_user_agent(config):
     from databricks.sdk.dbutils import RemoteDbUtils