title: gevent not valid running Docker Registry
body: <p>I am attempting to run a Docker registry on Ubuntu 14 using the following command:</p>
  
  <pre><code>sudo gunicorn --access-logfile - --debug -k gevent -b 0.0.0.0:5000 -w 1 docker_registry.wsgi:application
  </code></pre>
  
  <p>Unfortunately, when I attempt this I get the following failure message:</p>
  
  <pre><code>Error: class uri 'gevent' invalid or not found:
  
  
  
  [Traceback (most recent call last):
  
    File "/usr/local/lib/python2.7/dist-packages/gunicorn/util.py", line 139, in load_class
  
      mod = import_module('.'.join(components))
  
    File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
  
      __import__(name)
  
    File "/usr/local/lib/python2.7/dist-packages/gunicorn/workers/ggevent.py", line 24, in &lt;module&gt;
  
      from gevent.server import StreamServer
  
    File "/usr/local/lib/python2.7/dist-packages/gevent/server.py", line 6, in &lt;module&gt;
  
      from gevent.socket import EWOULDBLOCK, socket
  
    File "/usr/local/lib/python2.7/dist-packages/gevent/socket.py", line 659, in &lt;module&gt;
  
      from gevent.ssl import sslwrap_simple as ssl, SSLError as sslerror, SSLSocket as SSLType
  
    File "/usr/local/lib/python2.7/dist-packages/gevent/ssl.py", line 386, in &lt;module&gt;
  
      def get_server_certificate(addr, ssl_version=PROTOCOL_SSLv3, ca_certs=None):
  
  NameError: name 'PROTOCOL_SSLv3' is not defined
  </code></pre>
  
  <p>I did some searching and discovered something that told me to install python-gevent in order to get the gevent:</p>
  
  <pre><code>sudo apt-get install python-gevent
  </code></pre>
  
  <p>I did this and a subsequent invocation of dpkg:</p>
  
  <pre><code>dpkg -l|grep python
  </code></pre>
  
  <p>shows that python-gevent is installed.</p>
  
  <p>Unfortunately, the install has not resolved the problem. I am still getting the same failure message saying that gevent isn't valid or found.</p>
  
  <p>Does anyone know how to resolve this problem??? Please advise...</p>