Functions hangs when trying to read stream from URL

[priyaananthasankar]

This issue happens on my Mac locally. I am unable to isolate the cause.
Attached is the zip file of my function, it inferences Tensorflow InceptionV3 model

Added sample code in init.py to read from img url (followed predict shark example) but when running the function, it hangs - breakpoint revealed it hangs while trying to do urllib read:

image_url = req.params.get('img')
image_data = urllib.request.urlopen(image_url).read()

Unzip the attached file and just create a virtual environment and pip install to see the results.
TEST.zip

This problem was steadily reproducible if a wrong file path was given to tensorflow's File open method,

outside of functions it fails, but within functions it hangs.

[priyaananthasankar]

Identified issue as being 403 forbidden when trying to read an image url without proper headers. I identified this by trying this out with Python shell which clearly tells me 403 forbidden, but python functions just hangs. Here is a snippet of code to try out:
Scenario 1

user_agent_header = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/535.19 (KHTML, like Gecko) Ubuntu/12.04 Chromium/18.0.1025.168 Chrome/18.0.1025.168 Safari/535.19'
**req_img = urllib.request.Request(image_url, headers={'User-Agent': user_agent_header})**
response_img = urllib.request.urlopen(req_img)
image_data = response_img.read()

Now remove the user_agent header in the line in bold above and function hangs.

Scenario 2

Try to read a file with wrong path using Tensorflow:

For eg: model_file is the absolute path to a model, just make it an invalid path. Function hangs.

with tf.gfile.FastGFile(model_file, 'rb') as f:
    graph_def = tf.GraphDef()
    graph_def.ParseFromString(f.read())
    _ = tf.import_graph_def(graph_def, name='')

[elprans]

@priyaananthasankar Can you elaborate on what you mean by "function hangs". The scenarios you listed generate a Python exception, which is propagated to the host as a Microsoft.Azure.WebJobs.Host.FunctionInvocationException, and the function execution is terminated. We have a test for that in the suite:

azure-functions-python-worker/tests/http_functions/unhandled_error/main.py

Lines 1 to 5 in 659c977

	import azure.functions as azf
	def main(req: azf.HttpRequest):
	1 / 0

[priyaananthasankar]

@elprans : No errors are thrown. Last seen log will be "Python HTTP trigger function processed a request" Basically nothing happens. The Postman or CURL will just be executing saying "Loading" etc without any response (good/bad). Run the same thing outside of functions, then I get an error saying this path does not exist etc.

[elprans]

This is indeed a bug in the worker. Certain user exceptions crash the worker. #225 should fix this.