A simple messenger based on WebSockets

Spark relies on the support provided by the default S2I builder for deploying a WSGI application using the gunicorn WSGI server. The requirements which need to be satisfied for this to work are:

• The WSGI application code file needs to be named wsgi.py.
• 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.
• The environment variable GUNICORN_CMD_ARGS has been set worker_class to tornado for gunicorn.

To run the project you will need:

• Python 3.5.2 or later
• Tornado 4.5.2
• Gunicorn 19.7.1
• virtualenv - optional

Creating a virtual environment:

virtualenv -p python3 ~/envs/env #choose a suitable place for a new environment

Activation of the virtual environment:

source ~/envs/env/bin/activate

cd PROJECT_PATH
pip install -r requirements.txt

Preparatory actions:

• In the file spark_app.py change the variable HOST to http://127.0.0.1:8000
• In the file static/scripts/main.js also change the variable wsHOST to ws://127.0.0.1:8000/ws

Run development server:

cd PROJECT_PATH
gunicorn -k tornado wsgi:application

For check, go to the address http://127.0.0.1:8000 in your browser on several tabs and try to send yourself a message

To deploy from the OpenShift web console, you should select python:3.5 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:3.5.

The HTTPS URL of this code repository which should be supplied to the Git Repository URL field when using Add to project is:

• https://github.com/melnik-ivan/spark.git

If using the oc command line tool instead of the OpenShift web console, to deploy, you can run:

oc new-app https://github.com/melnik-ivan/spark.git

In this case, because no language type was specified, OpenShift will determine the language by inspecting the code repository. Because the code repository contains a requirements.txt, it will subsequently be interpreted as including a Python application. When such automatic detection is used, python:latest will be used.

If needing to select a specific Python version when using oc new-app, you should instead use the form:

oc new-app python:3.5~https://github.com/melnik-ivan/spark.git

See more:

• os-sample-python
• nodejs-ex

• Tornado - The non-blocking web server and web application framework

• Melnik Ivan - github profile