Add gunicorn config file.

Author: GrahamDumpleton

.s2i/environment

@@ -0,0 +1 @@
+APP_CONFIG=config.py

README.md

@@ -10,6 +10,10 @@ This sample Python application relies on the support provided by the default S2I
 * The WSGI application entry point within the code file needs to be named ``application``.
 * The ``gunicorn`` package must be listed in the ``requirements.txt`` file for ``pip``.
 
+In addition, the ``.s2i/environment`` file has been created to allow environment variables to be set to override the behaviour of the default S2I builder for Python.
+
+* The environment variable ``APP_CONFIG`` has been set to declare the name of the config file for ``gunicorn``.
+
 ## Deployment Steps
 
 To deploy this sample Python web application from the OpenShift web console, you should select ``python:2.7``, ``python:3.3``, ``python:3.4`` or ``python:latest``, when using _Add to project_. Use of ``python:latest`` is the same as having selected the most up to date Python version available, which at this time is ``python:3.4``.

config.py

@@ -0,0 +1,7 @@
+import os
+
+workers = int(os.environ.get('GUNICORN_PROCESSES', '3'))
+threads = int(os.environ.get('GUNICORN_THREADS', '1'))
+
+forwarded_allow_ips = '*'
+secure_scheme_headers = { 'X-Forwarded-Proto': 'https' }