Accessing a URL in Windows machine from Docker Container - python-2.7

Question

I am a newbie to Docker and this is what I am trying out.
I have a Windows machine on which I have installed Docker using Virtual Box as per this link. I have built a base Ubuntu Image. Now in the Windows Machine I have a Rest Service running that has to be accessed by the docker container. I am accessing it via Python Requests module. What IP should I give to the requests module's get method?
I have tried following
r = requests.get('http://172.17.42.1:8090/app/rest/names');
and
r = requests.get('http://172.17.0.2:8090/app/rest/names');
172.17.0.2 is the IP of Docker Container and 172.17.42.1 is the Bridge IP.
In both cases the error is Connection Refused
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 55, in get
return request('get', url, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 44, in request
return session.request(method=method, url=url, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 383, in reques
t
resp = self.send(prep, **send_kwargs)
File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 486, in send
r = adapter.send(request, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/requests/adapters.py", line 378, in send
raise ConnectionError(e)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='172.17.0.2', port=8090): Ma
x retries exceeded with url: /app/rest/names(Caused by <class 'socket.error'>:
[Errno 111] Connection refused)
However I can access a public URL available.

Answer 1

The bridge IP address should work. If it doesn't, it might be because the application on the Windows machine is not listening on all IP addresses, or maybe there is some kind of firewalling.
You can check that the application is listening on the right port (and on all addresses!) with netstat -a -n -o (on the Windows machine), as explained here.
Maybe the Windows machine is only listening on 127.0.0.1 …?