CDK: Add base pydantic model for connector config and schemas (airbyt…

…ehq#8485)

* add base spec model

* fix usage of state_checkpoint_interval in case it is dynamic

* add schema base models, fix spelling, signatures and polishing

Co-authored-by: Eugene Kulak <kulak.eugene@gmail.com>

airbyte-cdk/python/CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## 0.1.42
+Add base pydantic model for connector config and schemas.
+
 ## 0.1.41
 Fix build error
 

airbyte-cdk/python/airbyte_cdk/destinations/destination.py

@@ -92,7 +92,7 @@ def run_cmd(self, parsed_args: argparse.Namespace) -> Iterable[AirbyteMessage]:
             return
         config = self.read_config(config_path=parsed_args.config)
         if self.check_config_against_spec or cmd == "check":
-            check_config_against_spec_or_exit(config, spec, self.logger)
+            check_config_against_spec_or_exit(config, spec)
 
         if cmd == "check":
             yield self._run_check(config=config)

airbyte-cdk/python/airbyte_cdk/entrypoint.py

@@ -84,7 +84,7 @@ def run(self, parsed_args: argparse.Namespace) -> Iterable[str]:
                 # jsonschema's additionalProperties flag wont fail the validation
                 config, internal_config = split_config(config)
                 if self.source.check_config_against_spec or cmd == "check":
-                    check_config_against_spec_or_exit(config, source_spec, self.logger)
+                    check_config_against_spec_or_exit(config, source_spec)
                 # Put internal flags back to config dict
                 config.update(internal_config.dict())
 

airbyte-cdk/python/airbyte_cdk/sources/abstract_source.py

@@ -171,7 +171,6 @@ def _read_incremental(
         if stream_state:
             logger.info(f"Setting state of {stream_name} stream to {stream_state}")
 
-        checkpoint_interval = stream_instance.state_checkpoint_interval
         slices = stream_instance.stream_slices(
             cursor_field=configured_stream.cursor_field, sync_mode=SyncMode.incremental, stream_state=stream_state
         )
@@ -186,6 +185,7 @@ def _read_incremental(
             for record_counter, record_data in enumerate(records, start=1):
                 yield self._as_airbyte_record(stream_name, record_data)
                 stream_state = stream_instance.get_updated_state(stream_state, record_data)
+                checkpoint_interval = stream_instance.state_checkpoint_interval
                 if checkpoint_interval and record_counter % checkpoint_interval == 0:
                     yield self._checkpoint_state(stream_name, stream_state, connector_state, logger)
 

airbyte-cdk/python/airbyte_cdk/sources/config.py

@@ -0,0 +1,65 @@
+#
+# Copyright (c) 2021 Airbyte, Inc., all rights reserved.
+#
+
+from typing import Any, Dict, List, MutableMapping, Optional
+
+from jsonschema import RefResolver
+from pydantic import BaseModel
+
+
+class BaseConfig(BaseModel):
+    """Base class for connector spec, adds the following behaviour:
+
+    - resolve $ref and replace it with definition
+    - replace all occurrences of anyOf with oneOf
+    - drop description
+    """
+
+    @classmethod
+    def _rename_key(cls, schema: Any, old_key: str, new_key: str) -> None:
+        """Iterate over nested dictionary and replace one key with another. Used to replace anyOf with oneOf. Recursive."
+
+        :param schema: schema that will be patched
+        :param old_key: name of the key to replace
+        :param new_key: new name of the key
+        """
+        if not isinstance(schema, MutableMapping):
+            return
+
+        for key, value in schema.items():
+            cls._rename_key(value, old_key, new_key)
+            if old_key in schema:
+                schema[new_key] = schema.pop(old_key)
+
+    @classmethod
+    def _expand_refs(cls, schema: Any, ref_resolver: Optional[RefResolver] = None) -> None:
+        """Iterate over schema and replace all occurrences of $ref with their definitions. Recursive.
+
+        :param schema: schema that will be patched
+        :param ref_resolver: resolver to get definition from $ref, if None pass it will be instantiated
+        """
+        ref_resolver = ref_resolver or RefResolver.from_schema(schema)
+
+        if isinstance(schema, MutableMapping):
+            if "$ref" in schema:
+                ref_url = schema.pop("$ref")
+                _, definition = ref_resolver.resolve(ref_url)
+                cls._expand_refs(definition, ref_resolver=ref_resolver)  # expand refs in definitions as well
+                schema.update(definition)
+            else:
+                for key, value in schema.items():
+                    cls._expand_refs(value, ref_resolver=ref_resolver)
+        elif isinstance(schema, List):
+            for value in schema:
+                cls._expand_refs(value, ref_resolver=ref_resolver)
+
+    @classmethod
+    def schema(cls, **kwargs) -> Dict[str, Any]:
+        """We're overriding the schema classmethod to enable some post-processing"""
+        schema = super().schema(**kwargs)
+        cls._rename_key(schema, old_key="anyOf", new_key="oneOf")  # UI supports only oneOf
+        cls._expand_refs(schema)  # UI and destination doesn't support $ref's
+        schema.pop("definitions", None)  # remove definitions created by $ref
+        schema.pop("description", None)  # description added from the docstring
+        return schema

airbyte-cdk/python/airbyte_cdk/sources/utils/schema_helpers.py

@@ -10,13 +10,49 @@
 from typing import Any, ClassVar, Dict, Mapping, Tuple
 
 import jsonref
-from airbyte_cdk.logger import AirbyteLogger
 from airbyte_cdk.models import ConnectorSpecification
 from jsonschema import validate
 from jsonschema.exceptions import ValidationError
 from pydantic import BaseModel, Field
 
 
+class JsonFileLoader:
+    """
+    Custom json file loader to resolve references to resources located in "shared" directory.
+    We need this for compatability with existing schemas cause all of them have references
+    pointing to shared_schema.json file instead of shared/shared_schema.json
+    """
+
+    def __init__(self, uri_base: str, shared: str):
+        self.shared = shared
+        self.uri_base = uri_base
+
+    def __call__(self, uri: str) -> Dict[str, Any]:
+        uri = uri.replace(self.uri_base, f"{self.uri_base}/{self.shared}/")
+        return json.load(open(uri))
+
+
+def resolve_ref_links(obj: Any) -> Dict[str, Any]:
+    """
+    Scan resolved schema and convert jsonref.JsonRef object to JSON serializable dict.
+
+    :param obj - jsonschema object with ref field resolved.
+    :return JSON serializable object with references without external dependencies.
+    """
+    if isinstance(obj, jsonref.JsonRef):
+        obj = resolve_ref_links(obj.__subject__)
+        # Omit existing definitions for external resource since
+        # we dont need it anymore.
+        obj.pop("definitions", None)
+        return obj
+    elif isinstance(obj, dict):
+        return {k: resolve_ref_links(v) for k, v in obj.items()}
+    elif isinstance(obj, list):
+        return [resolve_ref_links(item) for item in obj]
+    else:
+        return obj
+
+
 class ResourceSchemaLoader:
     """JSONSchema loader from package resources"""
 
@@ -42,10 +78,8 @@ def get_schema(self, name: str) -> dict:
             raise IOError(f"Cannot find file {schema_filename}")
         try:
             raw_schema = json.loads(raw_file)
-        except ValueError:
-            # TODO use proper logging
-            print(f"Invalid JSON file format for file {schema_filename}")
-            raise
+        except ValueError as err:
+            raise RuntimeError(f"Invalid JSON file format for file {schema_filename}") from err
 
         return self.__resolve_schema_references(raw_schema)
 
@@ -57,58 +91,20 @@ def __resolve_schema_references(self, raw_schema: dict) -> dict:
         :return JSON serializable object with references without external dependencies.
         """
 
-        class JsonFileLoader:
-            """
-            Custom json file loader to resolve references to resources located in "shared" directory.
-            We need this for compatability with existing schemas cause all of them have references
-            pointing to shared_schema.json file instead of shared/shared_schema.json
-            """
-
-            def __init__(self, uri_base: str, shared: str):
-                self.shared = shared
-                self.uri_base = uri_base
-
-            def __call__(self, uri: str) -> Dict[str, Any]:
-                uri = uri.replace(self.uri_base, f"{self.uri_base}/{self.shared}/")
-                return json.load(open(uri))
-
         package = importlib.import_module(self.package_name)
         base = os.path.dirname(package.__file__) + "/"
-
-        def resolve_ref_links(obj: Any) -> Dict[str, Any]:
-            """
-            Scan resolved schema and convert jsonref.JsonRef object to JSON
-            serializable dict.
-
-            :param obj - jsonschema object with ref field resovled.
-            :return JSON serializable object with references without external dependencies.
-            """
-            if isinstance(obj, jsonref.JsonRef):
-                obj = resolve_ref_links(obj.__subject__)
-                # Omit existance definitions for extenal resource since
-                # we dont need it anymore.
-                obj.pop("definitions", None)
-                return obj
-            elif isinstance(obj, dict):
-                return {k: resolve_ref_links(v) for k, v in obj.items()}
-            elif isinstance(obj, list):
-                return [resolve_ref_links(item) for item in obj]
-            else:
-                return obj
-
         resolved = jsonref.JsonRef.replace_refs(raw_schema, loader=JsonFileLoader(base, "schemas/shared"), base_uri=base)
         resolved = resolve_ref_links(resolved)
         return resolved
 
 
-def check_config_against_spec_or_exit(config: Mapping[str, Any], spec: ConnectorSpecification, logger: AirbyteLogger):
+def check_config_against_spec_or_exit(config: Mapping[str, Any], spec: ConnectorSpecification):
     """
     Check config object against spec. In case of spec is invalid, throws
     an exception with validation error description.
 
     :param config - config loaded from file specified over command line
     :param spec - spec object generated by connector
-    :param logger - Airbyte logger for reporting validation error
     """
     spec_schema = spec.connectionSpecification
     try:
@@ -122,8 +118,10 @@ class InternalConfig(BaseModel):
     limit: int = Field(None, alias="_limit")
     page_size: int = Field(None, alias="_page_size")
 
-    def dict(self):
-        return super().dict(by_alias=True, exclude_unset=True)
+    def dict(self, *args, **kwargs):
+        kwargs["by_alias"] = True
+        kwargs["exclude_unset"] = True
+        return super().dict(*args, **kwargs)
 
 
 def split_config(config: Mapping[str, Any]) -> Tuple[dict, InternalConfig]:

airbyte-cdk/python/airbyte_cdk/sources/utils/schema_models.py

@@ -0,0 +1,76 @@
+#
+# Copyright (c) 2021 Airbyte, Inc., all rights reserved.
+#
+
+from typing import Any, Dict, Optional, Type
+
+from pydantic import BaseModel, Extra
+from pydantic.main import ModelMetaclass
+from pydantic.typing import resolve_annotations
+
+
+class AllOptional(ModelMetaclass):
+    """
+    Metaclass for marking all Pydantic model fields as Optional
+    Here is example of declaring model using this metaclass like:
+    '''
+            class MyModel(BaseModel, metaclass=AllOptional):
+                a: str
+                b: str
+    '''
+    it is an equivalent of:
+    '''
+            class MyModel(BaseModel):
+                a: Optional[str]
+                b: Optional[str]
+    '''
+    It would make code more clear and eliminate a lot of manual work.
+    """
+
+    def __new__(mcs, name, bases, namespaces, **kwargs):
+        """
+        Iterate through fields and wrap then with typing.Optional type.
+        """
+        annotations = resolve_annotations(namespaces.get("__annotations__", {}), namespaces.get("__module__", None))
+        for base in bases:
+            annotations = {**annotations, **getattr(base, "__annotations__", {})}
+        for field in annotations:
+            if not field.startswith("__"):
+                annotations[field] = Optional[annotations[field]]
+        namespaces["__annotations__"] = annotations
+        return super().__new__(mcs, name, bases, namespaces, **kwargs)
+
+
+class BaseSchemaModel(BaseModel):
+    """
+    Base class for all schema models. It has some extra schema postprocessing.
+    Can be used in combination with AllOptional metaclass
+    """
+
+    class Config:
+        extra = Extra.allow
+
+        @classmethod
+        def schema_extra(cls, schema: Dict[str, Any], model: Type[BaseModel]) -> None:
+            """Modify generated jsonschema, remove "title", "description" and "required" fields.
+
+            Pydantic doesn't treat Union[None, Any] type correctly when generate jsonschema,
+            so we can't set field as nullable (i.e. field that can have either null and non-null values),
+            We generate this jsonschema value manually.
+
+            :param schema: generated jsonschema
+            :param model:
+            """
+            schema.pop("title", None)
+            schema.pop("description", None)
+            schema.pop("required", None)
+            for name, prop in schema.get("properties", {}).items():
+                prop.pop("title", None)
+                prop.pop("description", None)
+                allow_none = model.__fields__[name].allow_none
+                if allow_none:
+                    if "type" in prop:
+                        prop["type"] = ["null", prop["type"]]
+                    elif "$ref" in prop:
+                        ref = prop.pop("$ref")
+                        prop["oneOf"] = [{"type": "null"}, {"$ref": ref}]

airbyte-cdk/python/setup.py

@@ -15,7 +15,7 @@
 
 setup(
     name="airbyte-cdk",
-    version="0.1.41",
+    version="0.1.42",
     description="A framework for writing Airbyte Connectors.",
     long_description=README,
     long_description_content_type="text/markdown",

airbyte-cdk/python/unit_tests/destinations/test_destination.py

@@ -172,7 +172,7 @@ def test_run_check(self, mocker, destination: Destination, tmp_path):
         # Affirm to Mypy that this is indeed a method on this mock
         destination.check.assert_called_with(logger=ANY, config=dummy_config)  # type: ignore
         # Check if config validation has been called
-        validate_mock.assert_called_with(dummy_config, spec_msg, destination.logger)
+        validate_mock.assert_called_with(dummy_config, spec_msg)
 
         # verify output was correct
         assert _wrapped(expected_check_result) == returned_check_result
@@ -224,7 +224,7 @@ def test_run_write(self, mocker, destination: Destination, tmp_path, monkeypatch
             input_messages=OrderedIterableMatcher(mocked_input),
         )
         # Check if config validation has been called
-        validate_mock.assert_called_with(dummy_config, spec_msg, destination.logger)
+        validate_mock.assert_called_with(dummy_config, spec_msg)
 
         # verify output was correct
         assert expected_write_result == returned_write_result