title: Docker build error "Cannot fetch index base URL http://pypi.python.org/simple/"
body: <p>I am building a dockerfile with the <code>docker build .</code> command. While building, I am experiencing the following error:</p>
  
  <pre><code>Downloading/unpacking requests
     Cannot fetch index base URL http://pypi.python.org/simple/
     Could not find any downloads that satisfy the requirement requests
     No distributions at all found for requests
  </code></pre>
  
  <p>Here is the dockerfile:</p>
  
  <pre><code>FROM jonasbonno/rpi-grovepi
  RUN pip install requests
  RUN git clone https://github.com/keyban/fogservice.git #update
  ENTRYPOINT ["python"]
  CMD ["fogservice/service.py"]
  </code></pre>
  
  <p>What might be the problem?</p>