AWS SAM Local dotnetcore2.1 exception when running API Gateway - .net-core

Question

Setup
Windows 10
Docker for Windows v18.09.0
AWS SAM CLI v0.10.0
Python 3.7.0
AWS CLI v1.16.67
dotnet core sdk v2.1.403
Powershell v5.1.17134.407
Problem
I'm following the quickstart for AWS SAM Local (as well as the readme generated once the init command is executed below), using the dotnetcore2.1 runtime.
I've run the following command to initialise AWS SAM for use with dotnetcore2.1
sam init --runtime dtonetcore2.1
Then I created the package by running
build.ps1 --target=package
Finally I start the local API Gateway service by running
sam local start-api
I then open a browser and navigate to http://localhost:3000/hello where I'm presented with the following:
PS C:\Users\user_name\Documents\Workspace\messaround\aws-sam\sam-app> sam local start-api
2019-01-04 10:39:15 Found credentials in shared credentials file: ~/.aws/credentials
2019-01-04 10:39:15 Mounting HelloWorldFunction at http://127.0.0.1:3000/hello [GET]
2019-01-04 10:39:15 You can now browse to the above endpoints to invoke your functions. You do not need to restart/reload SAM CLI while working on your functions changes will be reflected instantly/automatically. You only need to restart SAM CLI if you update your AWS SAM template
2019-01-04 10:39:16 * Running on http://127.0.0.1:3000/ (Press CTRL+C to quit)
2019-01-04 10:40:10 Invoking HelloWorld::HelloWorld.Function::FunctionHandler (dotnetcore2.1)
2019-01-04 10:40:10 Decompressing C:\Users\user_name\Documents\Workspace\messaround\aws-sam\sam-app\artifacts\HelloWorld.zip
Fetching lambci/lambda:dotnetcore2.1 Docker container image......
2019-01-04 10:40:13 Mounting C:\Users\user_name\AppData\Local\Temp\tmpq0zka7a7 as /var/task:ro inside runtime container
2019-01-04 10:40:14 Exception on /hello [GET]
Traceback (most recent call last):
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\docker\api\client.py", line 246, in _raise_for_status
response.raise_for_status()
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\requests\models.py", line 940, in raise_for_status
raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 500 Server Error: Internal Server Error for url: http+docker://localnpipe/v1.35/containers/102dda11417068e01873242be2383c78c7ad4e2739fd4f8b42c1e0ea494d2bbb/start
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\flask\app.py", line 2292, in wsgi_app
response = self.full_dispatch_request()
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\flask\app.py", line 1815, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\flask\app.py", line 1718, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\flask\_compat.py", line 35, in reraise
raise value
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\flask\app.py", line 1813, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\flask\app.py", line 1799, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\samcli\local\apigw\local_apigw_service.py", line 153, in _request_handler
self.lambda_runner.invoke(route.function_name, event, stdout=stdout_stream_writer, stderr=self.stderr)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\samcli\commands\local\lib\local_lambda.py", line 85, in invoke
self.local_runtime.invoke(config, event, debug_context=self.debug_context, stdout=stdout, stderr=stderr)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\samcli\local\lambdafn\runtime.py", line 86, in invoke
self._container_manager.run(container)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\samcli\local\docker\manager.py", line 98, in run
container.start(input_data=input_data)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\samcli\local\docker\container.py", line 187, in start
real_container.start()
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\docker\models\containers.py", line 390, in start
return self.client.api.start(self.id, **kwargs)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\docker\utils\decorators.py", line 19, in wrapped
return f(self, resource_id, *args, **kwargs)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\docker\api\container.py", line 1075, in start
self._raise_for_status(res)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\docker\api\client.py", line 248, in _raise_for_status
raise create_api_error_from_http_exception(e)
File "C:\Users\user_name\AppData\Roaming\Python\Python37\site-packages\docker\errors.py", line 31, in create_api_error_from_http_exception
raise cls(e, response=response, explanation=explanation)
docker.errors.APIError: 500 Server Error: Internal Server Error ("error while creating mount source path '/host_mnt/c/Users/user_name/AppData/Local/Temp/tmpq0zka7a7': mkdir /host_mnt/c/Users/user_name/AppData: permission denied")
2019-01-04 10:40:14 127.0.0.1 - - [04/Jan/2019 10:40:14] "GET /hello HTTP/1.1" 502 -
2019-01-04 10:40:14 127.0.0.1 - - [04/Jan/2019 10:40:14] "GET /favicon.ico HTTP/1.1" 403 -
What I've tried
Resetting the shared drive credentials
Initially I though this was a permissioning error between my Windows drive and the VM running docker... After searching the docker forums I found this article which I've followed. However this doesn't seem to have changed the error message
Any suggestions would be greatly received. Thanks

Answer 1

That's how I fixed my problem:
When SAM CLI sees a zip, it unzip into a temp directory (looks to be C:/Users/user_name/AppData/Local/Temp/tmpq0zka7a7 in your case).
Docker must have access to that folder.
In my case, I've created a local user to give Docker access to shared drives and that local user didn't have access to C:/Users/user_name.
I gave it access and got my problem sorted. Maybe you can fix it the same way.
Try to run the following:
docker run --rm -v c:/Users/user_name:/data alpine ls /data
It should list c:/Users/user_name content if all is fine.
Good luck!