Python

Flask

Verifica la disponibilidad de Python, pip y Virtualenv:

[alumno@servidor ~]$ which python
/usr/bin/python
[alumno@servidor ~]$ python --version
Python 2.7.5
[alumno@servidor ~]$ which pip
/usr/bin/pip
[alumno@servidor ~]$ pip --version
pip 7.1.0 from /usr/lib/python2.7/site-packages (python 2.7)
[alumno@servidor ~]$ which virtualenv
which: no virtualenv in (/home/alumno/.local/bin:...)

Como usuario root, instala a Virtualenv:

[root@servidor ~]# pip install virtualenv
Collecting virtualenv
  Downloading virtualenv-13.1.0-py2.py3-none-any.whl (1.7MB)
Installing collected packages: virtualenv
Successfully installed virtualenv-13.1.0

Verifica la instalación de Virtualenv:

[alumno@servidor ~]$ which virtualenv
/usr/bin/virtualenv
[alumno@servidor ~]$ virtualenv --version
13.1.0

Crea el directorio para el proyecto (flask) y accede a él:

[alumno@servidor ~]$ mkdir -p $HOME/www/flask
[alumno@servidor ~]$ cd $HOME/www/flask

Crea un entorno virtual dentro de tu proyecto:

[alumno@servidor flask]$ virtualenv venv
New python executable in venv/bin/python
Installing setuptools, pip, wheel...done.

Activa el recien creado entorno virtual dentro de tu proyecto:
```
[alumno@servidor flask]$ . venv/bin/activate
(venv)[alumno@servidor flask]$
```
Observaciones: al activar el entorno virtual el prompt de la shell cambiará.

Instala a Flask de forma local, dentro de tu proyecto:

(venv)[alumno@servidor flask]$ pip install Flask
  InsecurePlatformWarning
Collecting Flask
  InsecurePlatformWarning
  Downloading Flask-0.10.1.tar.gz (544kB)
    100% |████████████████████████████████| 544kB 347kB/s 
Collecting Werkzeug>=0.7 (from Flask)
  Downloading Werkzeug-0.10.4-py2.py3-none-any.whl (293kB)
    100% |████████████████████████████████| 294kB 483kB/s 
Collecting Jinja2>=2.4 (from Flask)
  Downloading Jinja2-2.8-py2.py3-none-any.whl (263kB)
    100% |████████████████████████████████| 266kB 608kB/s 
Collecting itsdangerous>=0.21 (from Flask)
  Downloading itsdangerous-0.24.tar.gz (46kB)
    100% |████████████████████████████████| 49kB 770kB/s 
Collecting MarkupSafe (from Jinja2>=2.4->Flask)
  Downloading MarkupSafe-0.23.tar.gz
Building wheels for collected packages: Flask, itsdangerous, MarkupSafe
  Running setup.py bdist_wheel for Flask
  Stored in directory: /home/alumno/.cache/pip/wheels/d2/db/61/cb9b80526b8f3ba89248ec0a29d6da1bb6013681c930fca987
  Running setup.py bdist_wheel for itsdangerous
  Stored in directory: /home/alumno/.cache/pip/wheels/97/c0/b8/b37c320ff57e15f993ba0ac98013eee778920b4a7b3ebae3cf
  Running setup.py bdist_wheel for MarkupSafe
  Stored in directory: /home/alumno/.cache/pip/wheels/94/a7/79/f79a998b64c1281cb99fa9bbd33cfc9b8b5775f438218d17a7
Successfully built Flask itsdangerous MarkupSafe
Installing collected packages: Werkzeug, MarkupSafe, Jinja2, itsdangerous, Flask
Successfully installed Flask-0.10.1 Jinja2-2.8 MarkupSafe-0.23 Werkzeug-0.10.4 itsdangerous-0.24

Crea el archivo index.py (el punto de inicio de tu "aplicación") con el siguiente contenido:

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/')
def hello_world():
    return jsonify(mensaje="Hola mundo")

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8080)

Ejecuta tu aplicación:

(venv)[alumno@servidor flask]$ pwd
/home/alumno/www/flask
(venv)[alumno@servidor flask]$ python index.py 
 * Running on http://0.0.0.0:8080/ (Press CTRL+C to quit)

Con un cliente REST accede a http://localhost:8080

Python

Flask

Lecturas