This talk will show you how to create a really simple Flask API application. Keep its source code on Github and have wercker CI to automatically deploy successful commits to an OpenShift application CODE on github: https://github.com/rochacbruno/flask-openshift-wercker

2. Python & Flask
on OpenShift
deployed by
wercker CI

3. 1. Flask creating an API
2. Github and webhooks
3. OpenShift what is and how it works w/ Python
4. Wercker CI and deployment targets

4. Objective:
This talk will show you how to create a really
simple Flask API application. Keep its source
code on Github and have wercker CI to
automatically deploy successful commits to
an OpenShift application.

5. pip install -r requirements.txt
# The Flask Framework
flask
# A helper to run wsgi apps on OPenShift
shiftpy
# Test runner
pytest
pytest-flask

6. '/calc/<string:op>/<int:number>/<int:other>'
"sum", "sub", "mul", "div"
$ python api.py - running on localhost:5000

7. api.py
from flask import Flask, jsonify
api = Flask(__name__)
@api.route('/calc/<string:op>/<int:number>/<int:other>')
def calc(op, number, other):
operations = {"sum": lambda a, b: a + b,
"mul": lambda a, b: a * b,
"sub": lambda a, b: a - b,
"div": lambda a, b: a / b}
return jsonify({"result": operations[op](number, other)})
if __name__ == "__main__":
api.run(debug=True)

8. tests.py
import pytest
from flask import jsonify
from api import calc, api
@pytest.fixture
def app():
return api
def test_sum(app):
assert calc('sum', 1, 2).data == jsonify({'result': 3}).data
def test_mul(app):
assert calc('mul', 5, 3).data == jsonify({'result': 15}).data
def test_sub(app):
assert calc('sub', 10, 5).data == jsonify({'result': 5}).data
def test_div(app):
assert calc('div', 10, 2).data == jsonify({'result': 5}).data

9. py.test tests.py
====== test session starts =======
plugins: flask
collected 4 items
tests.py ....
==== 4 passed in 0.13 seconds ====

10. STEP 1: Create a github repository

11. Push to github:
$ ls api_project
.. api.py tests.py requirements.txt
$ git init
$ git remote add origin https://github.com/username/repo
$ git commit -am"first commit"
$ git push -u origin master

12. DEPLOY:
$ ssh user@yourserver.com
$ sudo apt-get install <all_deps>
$ git clone https://github.com/repo
$ # run tests on production environment
$ # setup paths and virtualenv
$ # setup webserver
$ # setup firewall

13. DEPLOY IN 1997:
$ ssh user@yourserver.com
$ sudo apt-get install <all_deps>
$ git clone https://github.com/repo
$ # run tests on production environment
$ # setup paths and virtualenv
$ # setup webserver
$ # setup firewall

16. wercker.yml
box: wercker/python
build:
steps:
- virtualenv:
name: My virtualenv
install_wheel: false
- script:
name: Install main requirements
code: pip install -r requirements.txt
- script:
name: Run Tests
code: py.test tests.py

18. Add wercker to project:
$ git add wercker.yml
$ git commit -m"added wercker CI"
$ git push -u origin master

20. wsgi.py or app.py
from app import app
from shiftpy.wsgi_utils import envify
app = application = envify(app)

21. .openshift/action_hooks/deploy
#!/bin/bash
source ${OPENSHIFT_PYTHON_DIR}virtenv/bin/activate
cd $OPENSHIFT_REPO_DIR
echo "installing requirements"
pip install -r requirements.txt --upgrade

22. Add OpenShift to project:
$ git add wsgi.py
$ git add .openshift
$ git commit -m"added openshift"
$ git push -u origin master

26. box: wercker/python
build:
steps:
- virtualenv:
name: My virtualenv
install_wheel: false
- script:
name: Install main requirements
code: pip install -r requirements.txt
- script:
name: Run Tests
code: py.test tests.py
deploy:
steps:
- script:
name: production
code: fab -R prod_server deploy
Custom Deploy Target - fabric, ansible, chef, puppet etc

27. DEPLOY TO

30. seunome

31. https://openshift.redhat.com/app/console/keys/new

33. Lets break the tests
@api.route('/calc/<string:op>/<int:number>/<int:other>')
def calc(op, number, other):
operations = {"sum": lambda a, b: a + b,
"mul": lambda a, b: a * b,
"sub": lambda a, b: a - b,
"div": lambda a, b: a / b}
# return jsonify({"result": operations[op](number, other)})
# Break the tests!!!
return jsonify({"result": "error"})

34. $ git commit -m"Breaking the tests!!!"
$ git push -u origin master

39. Fix it!
@api.route('/calc/<string:op>/<int:number>/<int:other>')
def calc(op, number, other):
operations = {"sum": lambda a, b: a + b,
"mul": lambda a, b: a * b,
"sub": lambda a, b: a - b,
"div": lambda a, b: a / b}
return jsonify({"result": operations[op](number, other)})
$ git commit -m"Fixing the tests!!!"
$ git push -u origin master

43. http://calculator-quokkaproject.rhcloud.com/calc/sum/2/2
http://calculator-quokkaproject.rhcloud.com/apidocs/index.html

44. https://github.com/rochacbruno/flask-openshift-wercker