sapientcoffee / simple-app

Simple non-boring "Hello World" Python Flask App

Big Rob Coffee Flask Application

Introduction

Over the last year or so I have testing and running demos on a number of platforms and environments. While a basic 'Hello Word' app would do its a little bit boring. As a result I have created a number of examples that I can use to learn or highlight the capabilities of these environments.

The idea ia that the appication can be deployed standalone to show how thinsg are packaged up and configured for use on the differnet platforms, it can also use used to show interaction with other compoenets like Redis or MySQL etc.

The thoughts that I had around deployments where using traditional server/virtual machine deployments and also container based making use of microservices. The platforms that I had in mind;

• Pivotal Cloud Foundry (PCF)
• Pivotal Web Services
• OSS Cloud Foundry
• Cisco Shipped
• Cisco Mantl
• Cisco Cloud Center
• Cisco Metacloud
• Docker
• Traditional Application
• Mircoservice Application

What is the app

When the application is running you will be presented with a simple web page with the option to vote for you favourite coffee bean (the vote function doesnt work yet!). It will also provide information about what container/host the page is being serverd by, this is useful when scaling the application out.

Configuration

The directory structure is;

.
├── Dockerfile
├── Procfile
├── README.md
├── app.py
├── requirements.txt
├── static
│   ├── images
│   │   ├── bigrob.png
│   │   ├── el-salvador.jpg
│   │   ├── ethiopia.jpg
│   │   └── rwanda.jpg
│   ├── js
│   │   ├── freelancer.js
│   │   └── freelancer.min.js
│   └── stylesheets
│       ├── bootstrap.min.css
│       ├── cover.css
│       ├── font-awesome.min.css
│       ├── freelancer.css
│       ├── freelancer.min.css
│       └── style.css
└── templates
    └── index.html

The static/ directory contains the images, javascript and CSS files used by the application. The templates/ directory contains the basis for the HTML page.

The app.py is the main code for the applicaton.

Getting started

Cloud Foundry

To run on Cloud Foundry, I tested on PWS

git clone https://github.com/clijockey/vote-app-flask.git
cd vote-ap-flask
cf push br-coffee

You obviously need to be logged into your cloud foundry instance. The cf CLI should then kick of the process to deploy your application on Cloud Foundry.

The important file in the directory for this is the Procfile file, it specifies what command is required to run the Python application in the container.

Running

Browse to the URL presented back you after the cf push command has complete.

To check it's running issue the cf apps command;

tmp/vote-app-flask [ cf apps                                                                                                                             master ] 3:44 PM
Getting apps in org ######## / space redwards as ##########...
OK

name        requested state   instances   memory   disk   urls
br-coffee   started           1/1         512M     512M   br-coffee.cfapps.io

To get more detail about the running app use the cf app <app name> command;

tmp/vote-app-flask [ cf app br-coffee                                                                                                                    master ] 3:44 PM
Showing health and status for app br-coffee in org ####### / space redwards as #########...
OK

requested state: started
instances: 1/1
usage: 512M x 1 instances
urls: br-coffee.cfapps.io
last uploaded: Wed Feb 1 14:51:03 UTC 2017
stack: cflinuxfs2
buildpack: python 1.5.14

     state     since                    cpu    memory          disk           details
#0   running   2017-02-01 03:16:01 PM   0.0%   16.5M of 512M   116M of 512M

Remove

To remove the application if you no longer need it run cf delete <app name>;

tmp/vote-app-flask [ cf delete br-coffee             master ] 3:41 PM

Really delete the app br-coffee?> y
Deleting app br-coffee in org ####### / space redwards as ##########...
OK

Docker

NOTE: Since migrating the voting component to an individual repo this need to be be retested. A working version is here.

Download Docker for Mac or Windows.

git clone https://github.com/clijockey/vote-app-flask.git
cd vote-ap-flask
docker build -t br-coffee .

The app will be running at http://localhost:5000.

Architecture

This repo holds the front-end voting compoents however the following architecture is what I had in mind. You can see a single repo here

• A Python webapp which lets you vote between two options
• A Redis queue which collects new votes
• A .NET worker which consumes votes and stores them in…
• A Postgres database backed by a Docker volume
• A Node.js webapp which shows the results of the voting in real time

Credit

I have to give credit to a number of different sources. Firstly I used as the base of my voting app something that Docker created and adapted a bootstrap theme called freelancer.

simple-app's Issues

Resdis

Not yet got the Redis configuration done

Running with Docker

Doesn't run on Docker any more.