Empty file Content-type error

[IgnacioHeredia]

When a module has an predict arg which is a file (eg. image), but the arg is not required, deepaas fails to run:

        "demo-image": fields.Field(
            required=False,
            type="file",
            location="form",
            description="image",  # description needed to be parsed by UI
        ),

Seems to be related to the Content-type header in the aiohttp call. I opened a branch in the demo-app to test this: empty-file-form.

This issue was originally raised by @emvollmer (Nov. 2023)

Error logs

2024-04-30 15:46:17.946 162826 ERROR aiohttp.server [-] Error handling request: ValueError: boundary missed for Content-Type: multipart/form-data
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server Traceback (most recent call last):
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_protocol.py", line 435, in _handle_request
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     resp = await request_handler(request)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_app.py", line 504, in _handle
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     resp = await handler(request)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_middlewares.py", line 117, in impl
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     return await handler(request)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_middlewares.py", line 108, in impl
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     return await handler(request)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_middlewares.py", line 117, in impl
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     return await handler(request)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/ignacio/projects/deephdc/deepaas/deepaas/api/v2/predict.py", line 66, in post
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     args = await aiohttpparser.parser.parse(handler_args, request)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/webargs/asyncparser.py", line 87, in parse
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     parsed = await self._parse_request(
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/webargs/asyncparser.py", line 59, in _parse_request
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     parsed_value = await self.parse_arg(
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/webargs/asyncparser.py", line 206, in parse_arg
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     value = await self._get_value(name, field, req=req, location=location)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/webargs/asyncparser.py", line 217, in _get_value
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     value = await function(req, name, argobj)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/webargs/aiohttpparser.py", line 89, in parse_form
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     self._cache["post"] = await req.post()
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_request.py", line 689, in post
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     multipart = await self.multipart()
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/web_request.py", line 667, in multipart
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     return MultipartReader(self._headers, self._payload)
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/multipart.py", line 537, in __init__
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     self._boundary = ("--" + self._get_boundary()).encode()
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server   File "/home/iheredia/anaconda3/lib/python3.8/site-packages/aiohttp/multipart.py", line 636, in _get_boundary
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server     raise ValueError(
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server ValueError: boundary missed for Content-Type: multipart/form-data
2024-04-30 15:46:17.946 162826 ERROR aiohttp.server 
2024-04-30 15:46:17.948 162826 INFO aiohttp.access [-] 127.0.0.1 [30/Apr/2024:13:46:17 +0000] "POST /v2/models/ai4os_demo_app/predict/?demo-str=some-string&demo-str-choice=choice2&demo-int=1&demo-int-range=50&demo-float=0.1&demo-bool=true&demo-dict=%7B%22a%22%3A%200%2C%20%22b%22%3A%201%7D&demo-list-of-floats=0.1&demo-list-of-floats=0.2&demo-list-of-floats=0.3 HTTP/1.1" 500 244 "http://0.0.0.0:5000/api" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36"

[IgnacioHeredia]

Tried to inspect this but at that point args are already parsed by aiohttp.