ModelCreator: check early if model exists

.travis.yml

@@ -59,13 +59,13 @@ script: tox
 env:
     global:
       # DAR_CLIENT_ID
-      - secure: "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"
+      - secure: "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"
       # DAR_CLIENT_SECRET
-      - secure: "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"
+      - secure: "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"
       # DAR_AUTH_URL
-      - secure: "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"
+      - secure: "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"
       # DAR_URL
-      - secure: "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"
+      - secure: "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"
 
 jobs:
   include:
@@ -76,28 +76,28 @@ jobs:
     script:
     - pyenv global 3.7.1
     - pre-commit run --all-files
-#  - stage: system tests
-#    os: windows
-#    language: shell       # 'language: python' is an error on Travis CI Windows
-#    before_install:
-#      - choco install python --version 3.8.2
-#      - python -m pip install --upgrade pip
-#    env: PATH=/c/Python38:/c/Python38/Scripts:$PATH
-#    # use install: from global test stage, since system tests are
-#    # also handled via tox
-#    script:
-#      - tox -e system_tests
-#    deploy:
-#      - provider: releases
-#        skip_cleanup: true
-#        api_key:
-#          # API key for a machine user specifically created for this task:
-#          # https://github.com/dar-sdk-machine-user
-#          secure: "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"
-#        file: "system_test_results/traceability.html"
-#        on:
-#          tags: true
-#          condition:  $TRAVIS_TAG =~ ^rel/.*$
+  - stage: system tests
+    os: windows
+    language: shell       # 'language: python' is an error on Travis CI Windows
+    before_install:
+      - choco install python --version 3.8.2
+      - python -m pip install --upgrade pip
+    env: PATH=/c/Python38:/c/Python38/Scripts:$PATH
+    # use install: from global test stage, since system tests are
+    # also handled via tox
+    script:
+      - tox -e system_tests
+    deploy:
+      - provider: releases
+        skip_cleanup: true
+        api_key:
+          # API key for a machine user specifically created for this task:
+          # https://github.com/dar-sdk-machine-user
+          secure: "m0kXSf53vJY95nb7lrM4N4KTiSmNuSoHfS3swxhjuoEdCPuaYHkpkHjPYH6ZNIjBbFEMGw4YENEcUdyzlshPe/WIX5IQ1LjFTZ1U9wP8Iup0VNW9NAHn32Q9oRUFKdD5IeCtjvQwGdVZbAoJM7+IwX19qqhgkPf1VEPPcq3zW+J/aZNg1ayfH+79x60vybapeG7a8QNvxNATrHaO07+xuWIoDaSKZA0ggDn2zxdaDGk/1SJRZsu67YA0DqFAYB8CtspgewJg7MIrLQcHps9yq+vp1sPHiWy9SH87CDyG9+NMXBb2rnvsmRwxXI659wFOQqMWmCgSs/L3IMPBCGziSqgw7MG5hLVpyrmExINuag2yricm0RDPYVxnJKBz3a7J4pl1zudpdfudich8WDinJk7TJHR3tTgIFx1ASmA20RiY22NUvHWpRL88jNJn5LXDyOaT5bT7c6i9VwxpUq234DXLQ9iUMrbs5P576x/Px71dfJ8RLv52D4TmwQYVzgRdFeFI/TOvyvIKA4dYfGylpsueIScZTn5G0p9srzqpRT8gr1sOlIsBHjISppeyEG6C3uTuhaP/zu7o+soQtiMHWm7G2/5BpUBz7JwMODMnK1f4B4stQJYo7Kx+KsGPUrkJVst07klya44EYGS7Ik8Dm6YsNhvc0safYxxNK71cqGY="
+        file: "system_test_results/traceability.html"
+        on:
+          tags: true
+          condition:  $TRAVIS_TAG =~ ^rel/.*$
   - stage: test
     name: "Python: 3.8 on Windows"
     # https://docs.travis-ci.com/user/languages/python/#running-python-tests-on-multiple-operating-systems

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 * Documentation: add link to SAP community [#58]
+* `ModelCreator.create` performs an initial check if the model name is already used
+  and raises `ModelAlreadyExists` in this case [#60], [#64]
 
 ### Fixed
 
@@ -21,7 +23,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#46]: https://github.com/SAP/data-attribute-recommendation-python-sdk/issues/46
 [#58]: https://github.com/SAP/data-attribute-recommendation-python-sdk/pull/58
 [#59]: https://github.com/SAP/data-attribute-recommendation-python-sdk/pull/59
+[#60]: https://github.com/SAP/data-attribute-recommendation-python-sdk/issues/60
 [#63]: https://github.com/SAP/data-attribute-recommendation-python-sdk/pull/63
+[#64]: https://github.com/SAP/data-attribute-recommendation-python-sdk/pull/64
 
 ## [0.6.8]
 

sap/aibus/dar/client/exceptions.py

@@ -107,6 +107,31 @@ class DeploymentFailed(DARException):
     pass
 
 
+class ModelAlreadyExists(DARException):
+    """
+    Model already exists and must be deleted first.
+
+    Note that this is not really used by the :class:`ModelManagerClient`, but
+    rather by higher-level methods in :class:`ModelCreator` and similar.
+
+    For methods interacting directly with the API, a request which will
+    conflict will instead raise a :class:`DARHTTPException` with an appropriate code.
+    """
+
+    def __init__(self, model_name: str):
+        """
+        Constructor.
+
+        :param: model_name: Name of the model which alreadx exists
+        """
+        msg = "Model '%s' already exists." % model_name
+        msg += (
+            "To re-use the name, please delete the model"
+            " first or choose a different name."
+        )
+        super(ModelAlreadyExists, self).__init__(msg)
+
+
 class DARHTTPException(DARException):
     """
     Error occured when talking to the DAR service over HTTP.

sap/aibus/dar/client/workflow/model.py

@@ -6,6 +6,7 @@
 
 from sap.aibus.dar.client.base_client import BaseClient
 from sap.aibus.dar.client.data_manager_client import DataManagerClient
+from sap.aibus.dar.client.exceptions import ModelAlreadyExists, DARHTTPException
 from sap.aibus.dar.client.model_manager_client import ModelManagerClient
 from sap.aibus.dar.client.util.credentials import CredentialsSource
 
@@ -62,8 +63,21 @@ def create(
         :raises: DatasetValidationTimeout: if validation takes too long
         :raises: DatasetValidationFailed: if validation does not finish in state
                 *SUCCEEDED*
+        :raises: ModelAlreadyExists: if model already exists at start of process
         :return:
         """
+
+        self.log.info("Checking if model exists")
+        try:
+            self.model_manager_client.read_model_by_name(model_name=model_name)
+        except DARHTTPException as exception:
+            if exception.status_code == 404:
+                pass
+            else:
+                raise
+        else:
+            raise ModelAlreadyExists(model_name)
+
         self.log.info("Creating DatasetSchema.")
         response_dataset_schema = self.data_manager_client.create_dataset_schema(
             dataset_schema

system_tests/workflow/test_end_to_end.py

@@ -5,15 +5,15 @@
 import pytest
 
 from sap.aibus.dar.client.data_manager_client import DataManagerClient
-from sap.aibus.dar.client.exceptions import DARHTTPException
+from sap.aibus.dar.client.exceptions import DARHTTPException, ModelAlreadyExists
 from sap.aibus.dar.client.inference_client import InferenceClient
 from sap.aibus.dar.client.model_manager_client import ModelManagerClient
 from sap.aibus.dar.client.workflow.model import ModelCreator
 
 logger = logging.getLogger("test")
 
 
-@pytest.mark.requirements(issues=["42"])
+@pytest.mark.requirements(issues=["42", "60"])
 class TestEndToEnd:
     """
     Tests an end-to-end scenario:
@@ -86,6 +86,17 @@ def test_create(
         assert resp["name"] == model_name
         assert "validationResult" in resp
 
+        # Now that the model exists, a second, identical call should
+        # raise a ModelAlreadyExists exception.
+
+        with pytest.raises(ModelAlreadyExists):
+            model_creator.create(
+                model_template_id="d7810207-ca31-4d4d-9b5a-841a644fd81f",
+                dataset_schema=new_schema,
+                model_name=model_name,
+                data_stream=data_stream,
+            )
+
         # Check if model is indeed there
         self._assert_model_exists(model_manager_client, model_name)
 

tests/sap/aibus/dar/client/test_exceptions.py

@@ -1,7 +1,7 @@
 import datetime
 from unittest.mock import PropertyMock
 
-from sap.aibus.dar.client.exceptions import DARHTTPException
+from sap.aibus.dar.client.exceptions import DARHTTPException, ModelAlreadyExists
 from tests.sap.aibus.dar.client.test_dar_session import create_mock_response
 
 # TODO: test __str__
@@ -153,3 +153,14 @@ def test_reason_works_unicode_object(self):
 
         exception = DARHTTPException.create_from_response(url, mock_response)
         assert exception.response_reason == "ÄÖÜ"
+
+
+class TestModelAlreadyExists:
+    def test_message(self):
+        e = ModelAlreadyExists(model_name="a-name")
+        expected_message = "Model 'a-name' already exists."
+        expected_message += (
+            "To re-use the name, please delete the model"
+            " first or choose a different name."
+        )
+        assert str(e) == expected_message

tests/sap/aibus/dar/workflow/test_model.py

@@ -7,6 +7,7 @@
 
 from sap.aibus.dar.client.base_client import BaseClient
 from sap.aibus.dar.client.data_manager_client import DataManagerClient
+from sap.aibus.dar.client.exceptions import ModelAlreadyExists, DARHTTPException
 from sap.aibus.dar.client.util.credentials import (
     StaticCredentialsSource,
     CredentialsSource,
@@ -37,6 +38,31 @@ def csv_data_stream():
     return data_stream
 
 
+@pytest.fixture()
+def create_model():
+    create_model = ModelCreator.construct_from_jwt("https://abcd/", token="54321")
+    create_model.data_manager_client = create_autospec(DataManagerClient, instance=True)
+    create_model.model_manager_client = create_autospec(
+        ModelManagerClient, instance=True
+    )
+    return create_model
+
+
+@pytest.fixture()
+def model_resource():
+    return {
+        "jobId": "522de4e6-2609-4972-8f75-61e9262b86de",
+        "name": "my-model",
+        "createdAt": "2018-08-31T11:45:54+00:00",
+        "validationResult": {
+            "accuracy": 0.9,
+            "f1Score": 0.9,
+            "precision": 0.9,
+            "recall": 0.9,
+        },
+    }
+
+
 a_timestamp = datetime.datetime(
     2011, 11, 4, 0, 5, 23, 283000, tzinfo=datetime.timezone.utc
 )
@@ -108,7 +134,7 @@ def test_format_dataset_name_excessive_length_is_truncated(self):
         # First part is still all a's
         assert formatted[:-uuid_len] == input_str[0 : 255 - uuid_len]
 
-    def test_create_model(self, csv_data_stream):
+    def test_create_model(self, csv_data_stream, create_model, model_resource):
         # inputs
         # model_name: str,
 
@@ -145,23 +171,22 @@ def test_create_model(self, csv_data_stream):
             "datasetSchemaId": new_dataset_schema_id,
         }
 
-        create_model = ModelCreator.construct_from_jwt("https://abcd/", token="54321")
-        create_model.data_manager_client = create_autospec(
-            DataManagerClient, instance=True
-        )
-        create_model.model_manager_client = create_autospec(
-            ModelManagerClient, instance=True
-        )
-
         create_model.format_dataset_name = Mock(return_value=dataset_name)
 
-        dm = create_model.data_manager_client
+        create_model.data_manager_client.create_dataset_schema.return_value = (
+            dataset_schema_created
+        )
+        create_model.data_manager_client.create_dataset.return_value = dataset_created
 
-        dm.create_dataset_schema.return_value = dataset_schema_created
-        dm.create_dataset.return_value = dataset_created
+        dm = create_model.data_manager_client
 
         mm = create_model.model_manager_client
 
+        mm.read_model_by_name.side_effect = [
+            DARHTTPException(url="https://abcd/", response=Mock(status_code=404)),
+            model_resource,
+        ]
+
         # act
         result = create_model.create(
             data_stream=csv_data_stream,
@@ -170,7 +195,7 @@ def test_create_model(self, csv_data_stream):
             model_name=model_name,
         )
 
-        assert result == mm.read_model_by_name.return_value
+        assert result == model_resource
 
         # Expected calls
         expected_create_dataset_schema = call(dataset_schema)
@@ -205,5 +230,59 @@ def test_create_model(self, csv_data_stream):
         expected_call_to_read_model_by_name = call(model_name=model_name)
 
         assert mm.read_model_by_name.call_args_list == [
-            expected_call_to_read_model_by_name
+            expected_call_to_read_model_by_name,
+            expected_call_to_read_model_by_name,
+        ]
+
+    def test_create_model_checks_for_existing_model(self, create_model, model_resource):
+        """
+        If the model already exists, this should be an error.
+        """
+        model_name = "my-model"
+
+        create_model.model_manager_client.read_model_by_name.return_value = (
+            model_resource
+        )
+
+        with pytest.raises(ModelAlreadyExists) as context:
+            create_model.create(
+                data_stream=Mock(),
+                model_template_id=Mock(),
+                dataset_schema=Mock(),
+                model_name=model_name,
+            )
+
+        assert "Model 'my-model' already exists" in str(context.value)
+
+        assert create_model.model_manager_client.read_model_by_name.call_args_list == [
+            call(model_name=model_name)
+        ]
+
+    def test_create_model_forwards_exception(self, create_model, model_resource):
+        """
+        If ModelManagerClient.read_model_by_name raises a 404 in the initial check,
+        this means that the model is not there and execution and proceed. This is
+        tested in test_create_model above.
+
+        For all other status code, the exception should be re-raised as is.
+        This is tested here.
+        """
+        model_name = "my-model"
+
+        exc = DARHTTPException(url="https://abcd/", response=Mock(status_code=429))
+
+        create_model.model_manager_client.read_model_by_name.side_effect = exc
+
+        with pytest.raises(DARHTTPException) as context:
+            create_model.create(
+                data_stream=Mock(),
+                model_template_id=Mock(),
+                dataset_schema=Mock(),
+                model_name=model_name,
+            )
+
+        assert context.value == exc
+
+        assert create_model.model_manager_client.read_model_by_name.call_args_list == [
+            call(model_name=model_name)
         ]