Fix: VM connector does not start when run locally (#287)

* Fix: remove documentation of `use_latest`

Problem: the field does not appear in the VM connector API functions.

* Fix: FastAPI exception when launching the VM connector

Problem: launching the VM connector with `run_vm_connector.sh` yields
an exception because of issues with the return types of the API
endpoints.

Solution: remove `Response` and `StreamingResponse` type hints from
return values as they are not Pydantic models.

vm_connector/main.py

@@ -64,44 +64,43 @@ async def stream_url_chunks(url):
 
 
 @app.get("/download/message/{ref}")
-async def download_message(ref: str) -> Union[Dict, Response]:
+async def download_message(ref: str) -> Dict:
  """
  Fetch on Aleph and return a VM function message, after checking its validity.
  Used by the VM Supervisor run the code.
 
  :param ref: item_hash of the code file
- :param use_latest: should the last amend to the code be used
  :return: a file containing the code file
  """
 
  msg = await get_message(hash_=ref)
 
- # TODO: Validate the validity of the message (signature, hashes)
+ # TODO: Validate the message (signature, hashes)
+ if not msg:
+ raise HTTPException(status_code=404, detail="Hash not found")
 
- return msg or Response(status_code=404, content="Hash not found")
+ return msg
 
 
 @app.get("/download/code/{ref}")
-async def download_code(ref: str) -> Union[StreamingResponse, Response]:
+async def download_code(ref: str):
  """
  Fetch on Aleph and return a VM code file, after checking its validity.
  Used by the VM Supervisor to download function source code.
 
  :param ref: item_hash of the code file
- :param use_latest: should the last amend to the code be used
  :return: a file containing the code file
  """
  return await download_data(ref=ref)
 
 
 @app.get("/download/data/{ref}")
-async def download_data(ref: str) -> Union[StreamingResponse, Response]:
+async def download_data(ref: str):
  """
  Fetch on Aleph and return a VM data file, after checking its validity.
  Used by the VM Supervisor to download state data.
 
  :param ref: item_hash of the data
- :param use_latest: should the last amend to the data be used
  :return: a file containing the data
  """
 
@@ -122,13 +121,12 @@ async def download_data(ref: str) -> Union[StreamingResponse, Response]:
 
 
 @app.get("/download/runtime/{ref}")
-async def download_runtime(ref: str) -> Union[StreamingResponse, Response]:
+async def download_runtime(ref: str):
  """
  Fetch on Aleph and return a VM runtime, after checking its validity.
  Used by the VM Supervisor to download a runtime.
 
  :param ref: item_hash of the runtime
- :param use_latest: should the last amend to the runtime be used
  :return: a file containing the runtime
  """
  return await download_data(ref=ref)