Better error handling in Repos (#428)

In current version, we have "catch-all" error handling that efficiently hides the actual
reason for the error. It's not possible to understand the reason for error, for example,
when IP Access List is used. This patch improves the error reporting:

Without patch

```
Error: RuntimeError: Can't find repo ID for /Repos/user/repo
```

With patch:

```
Error: RuntimeError: Error fetching repo ID for /Repos/user/repo: HTTP code: 403, Unauthorized access to Org: 1234567890
```

Author: alexott

databricks_cli/repos/api.py

@@ -40,14 +40,22 @@ def get_repo_id(self, path):
             status = self.ws_client.get_status(path)
             if status['object_type'] == 'REPO':
                 return status['object_id']
-        except requests.exceptions.HTTPError:
-            pass
+        except requests.exceptions.HTTPError as ex:
+            if ex.response.status_code != 404:
+                jsn = ex.response.json()
+                if 'message' in jsn:
+                    msg = jsn['message']
+                else:
+                    msg = ex.response.reason
+                raise RuntimeError(
+                    "Error fetching repo ID for {path}: HTTP code: {code}, {ex}".format(
+                        path=path, code=ex.response.status_code, ex=msg))
 
         raise RuntimeError("Can't find repo ID for {path}".format(path=path))
 
     def list(self, path_prefix, next_page_token):
         """
-        List repos that the caller has Manage permissions on. Results are 
+        List repos that the caller has Manage permissions on. Results are
         paginated with each page containing twenty repos.
         """
         return self.client.list_repos(path_prefix, next_page_token)
@@ -66,7 +74,7 @@ def get(self, repo_id):
 
     def update(self, repo_id, branch, tag):
         """
-        Checks out the repo to the given branch or tag. Only one of ``branch`` 
+        Checks out the repo to the given branch or tag. Only one of ``branch``
         or ``tag`` should be provided.
         """
         assert bool(branch is not None) ^ bool(tag is not None)

tests/repos/test_api.py

@@ -22,10 +22,12 @@
 # limitations under the License.
 
 # pylint:disable=redefined-outer-name
+import json
 
 import mock
 
 import pytest
+import requests
 
 import databricks_cli.repos.api as api
 import databricks_cli.workspace.api as workspace_api
@@ -44,6 +46,10 @@
     'created_at': 124,
     'object_id': TEST_ID,
 }
+TEST_ERROR_JSON_RESPONSE = {
+    'error': "Permission Denied",
+    'message': "Unauthorized access to Org: 123456",
+}
 
 
 @pytest.fixture()
@@ -72,4 +78,13 @@ def test_get_id_path_not_in_repos(self, repos_api_with_ws_service):
     def test_get_id_not_a_repo(self, repos_api_with_ws_service):
         repos_api_with_ws_service.ws_client.get_status.return_value = TEST_NON_REPO_JSON_RESPONSE
         with pytest.raises(RuntimeError):
-            repos_api_with_ws_service.get_repo_id(TEST_PATH)
+            repos_api_with_ws_service.get_repo_id(TEST_PATH)
+
+    def test_get_id_other_error(self, repos_api_with_ws_service):
+        response = requests.Response()
+        response.status_code = 403
+        response._content = json.dumps(TEST_ERROR_JSON_RESPONSE).encode() #  NOQA
+        repos_api_with_ws_service.ws_client.get_status.side_effect = mock.Mock(
+            side_effect=requests.exceptions.HTTPError(response=response))
+        with pytest.raises(RuntimeError):
+            repos_api_with_ws_service.get_repo_id(TEST_PATH)

tests/repos/test_cli.py

@@ -139,4 +139,4 @@ def test_delete_validation(repos_api_mock):
                   ["--repo-id", TEST_ID])
     repos_api_mock.delete.assert_called_once_with(
         TEST_ID,
-    )
+    )