feat: additional interpolation contexts for download step of async job (#757)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: dbgold17

airbyte_cdk/sources/declarative/declarative_component_schema.yaml

@@ -3797,7 +3797,6 @@ definitions:
       - polling_requester
       - download_requester
       - status_extractor
-      - download_target_extractor
     properties:
       type:
         type: string

airbyte_cdk/sources/declarative/models/declarative_component_schema.py

@@ -2852,8 +2852,8 @@ class AsyncRetriever(BaseModel):
     status_extractor: Union[DpathExtractor, CustomRecordExtractor] = Field(
         ..., description="Responsible for fetching the actual status of the async job."
     )
-    download_target_extractor: Union[DpathExtractor, CustomRecordExtractor] = Field(
-        ...,
+    download_target_extractor: Optional[Union[DpathExtractor, CustomRecordExtractor]] = Field(
+        None,
         description="Responsible for fetching the final result `urls` provided by the completed / finished / ready async job.",
     )
     download_extractor: Optional[

airbyte_cdk/sources/declarative/parsers/model_to_component_factory.py

@@ -3467,6 +3467,11 @@ def create_async_retriever(
         transformations: List[RecordTransformation],
         **kwargs: Any,
     ) -> AsyncRetriever:
+        if model.download_target_requester and not model.download_target_extractor:
+            raise ValueError(
+                f"`download_target_extractor` required if using a `download_target_requester`"
+            )
+
         def _get_download_retriever(
             requester: Requester, extractor: RecordExtractor, _decoder: Decoder
         ) -> SimpleRetriever:
@@ -3624,11 +3629,15 @@ def _get_job_timeout() -> datetime.timedelta:
         status_extractor = self._create_component_from_model(
             model=model.status_extractor, decoder=decoder, config=config, name=name
         )
-        download_target_extractor = self._create_component_from_model(
-            model=model.download_target_extractor,
-            decoder=decoder,
-            config=config,
-            name=name,
+        download_target_extractor = (
+            self._create_component_from_model(
+                model=model.download_target_extractor,
+                decoder=decoder,
+                config=config,
+                name=name,
+            )
+            if model.download_target_extractor
+            else None
         )
 
         job_repository: AsyncJobRepository = AsyncHttpJobRepository(

airbyte_cdk/sources/declarative/requesters/README.md

@@ -1,8 +1,19 @@
+# Download Target and Download Requester
+
+- The `creation_response` and `polling_response` interpolation contexts are always available during the job download step of the process.
+
+- The`download_target` interpolation context is generated by the `download_target_extractor` and made available to the job download step as well.
+  - if `download_target_requester` is not provided, `download_target_extractor` will get urls from the `polling_response`
+  - if `download_target_requester` is provided, an additional request will be made to fetch job download targets and `download_target_extractor` will operate on that response
+
+## Some important considerations
+
+- **Note:** If the `download_target_extractor` and `download_target_requester` are not defined, a single job download request will be made without the `download_target` context.
+- **Note:** The `download_target_extractor` is required (not optional) if using a `download_target_requester`
+
 # AsyncHttpJobRepository sequence diagram
 
 - Components marked as optional are not required and can be ignored.
-- if `download_target_requester` is not provided, `download_target_extractor` will get urls from the `polling_response`
-- interpolation_context, e.g. `creation_response` or `polling_response` can be obtained from stream_slice
 
 ```mermaid
 ---
@@ -37,7 +48,7 @@ sequenceDiagram
         UrlRequester -->> AsyncHttpJobRepository: Download URLs
 
         AsyncHttpJobRepository ->> DownloadRetriever: Download reports
-        DownloadRetriever ->> Reporting Server: Retrieve report data (interpolation_context: `url`)
+        DownloadRetriever ->> Reporting Server: Retrieve report data (interpolation_context: `download_target`, `creation_response`, `polling_response`)
         Reporting Server -->> DownloadRetriever: Report data
         DownloadRetriever -->> AsyncHttpJobRepository: Report data
     else Status: Failed

airbyte_cdk/sources/declarative/requesters/http_job_repository.py

@@ -43,7 +43,7 @@ class AsyncHttpJobRepository(AsyncJobRepository):
     delete_requester: Optional[Requester]
     status_extractor: DpathExtractor
     status_mapping: Mapping[str, AsyncJobStatus]
-    download_target_extractor: DpathExtractor
+    download_target_extractor: Optional[DpathExtractor]
 
     # timeout for the job to be completed, passed from `polling_job_timeout`
     job_timeout: Optional[timedelta] = None
@@ -213,14 +213,16 @@ def fetch_records(self, job: AsyncJob) -> Iterable[Mapping[str, Any]]:
 
         """
 
-        for target_url in self._get_download_targets(job):
+        for download_target in self._get_download_targets(job):
             job_slice = job.job_parameters()
             stream_slice = StreamSlice(
                 partition=job_slice.partition,
                 cursor_slice=job_slice.cursor_slice,
                 extra_fields={
                     **job_slice.extra_fields,
-                    "download_target": target_url,
+                    "download_target": download_target,
+                    "creation_response": self._get_creation_response_interpolation_context(job),
+                    "polling_response": self._get_polling_response_interpolation_context(job),
                 },
             )
             for message in self.download_retriever.read_records({}, stream_slice):
@@ -330,9 +332,27 @@ def _get_create_job_stream_slice(self, job: AsyncJob) -> StreamSlice:
         )
 
     def _get_download_targets(self, job: AsyncJob) -> Iterable[str]:
-        if not self.download_target_requester:
-            url_response = self._polling_job_response_by_id[job.api_job_id()]
-        else:
+        """Returns an iterable of strings to help target requests for downloading async jobs."""
+        # If neither download_target_extractor nor download_target_requester are provided, yield a single empty string
+        # to express the need to make a single download request without any download_target value
+        if not self.download_target_extractor:
+            if not self.download_target_requester:
+                lazy_log(
+                    LOGGER,
+                    logging.DEBUG,
+                    lambda: "No download_target_extractor or download_target_requester provided. Will attempt a single download request without a `download_target`.",
+                )
+                yield ""
+                return
+            else:
+                raise AirbyteTracedException(
+                    internal_message="Must define a `download_target_extractor` when using a `download_target_requester`.",
+                    failure_type=FailureType.config_error,
+                )
+
+        # We have a download_target_extractor, use it to extract the donload_target
+        if self.download_target_requester:
+            # if a download_target_requester if defined, we extract from the response of a request specifically for download targets.
             stream_slice: StreamSlice = StreamSlice(
                 partition={},
                 cursor_slice={},
@@ -346,5 +366,8 @@ def _get_download_targets(self, job: AsyncJob) -> Iterable[str]:
                     internal_message="Always expect a response or an exception from download_target_requester",
                     failure_type=FailureType.system_error,
                 )
+        else:
+            # if no download_target_requester is defined, we extract from the polling response
+            url_response = self._polling_job_response_by_id[job.api_job_id()]
 
         yield from self.download_target_extractor.extract_records(url_response)  # type: ignore # we expect download_target_extractor to always return list of strings