Simple webapps with ngnix, uwsgi emperor

and bottle

Jordi Soucheiron - @jordixouBackend engineer & sysadmin @ DEXMA

@ The Barcelona Python Meetup Group 2014.02.20

What is nginx

HTTP and reverse proxy server

Event driven

Very fast

Easy to configure

What is uWSGI

WSGI compatible server

VERY flexible

Little overhead

Compatible with many frameworks like: bottle, flask, django, …

What is bottle

Bottle is a fast, simple and lightweight WSGI web microframework

No additional dependencies

Uses decorators: @route, @get, @post, etc…

Bottle Hello World

mkdir –p /opt/uwsgiApps/apps/

cd /opt/uwsgiApps/apps/

virtualenv bottle-hello

cd bottle-hello

pip install bottle

Bottle Hello World

vi bottle-hello.py:

from bottle import route, run

@route('/hello')def hello(): return "Hello World!"

if __name__ == '__main__': run(port=8080, debug=True)else: application = app

Bottle Hello World

python bottle-hello.py

Try to access http://localhost:8080/

Bottle Hello World v2

Add this (after the initial imports) to bottle-hello.py:

python bottle-hello.py

Try to access http://localhost:8080/hello/yourname

from bottle import template@route('/hello/<name>')def greet(name='Stranger'): return template('Hello {{name}}, how are you?', name=name)

uWSGI installation

pip install uwsgi

vi /etc/init/uwsgi.conf:# uWSGI - manage uWSGI application server description "uWSGI Emperor"

start on (filesystem and net-device-up IFACE=lo)stop on runlevel [!2345]

respawn

env LOGTO=/var/log/uwsgi/uwsgi.logenv BINPATH=/usr/local/bin/uwsgi

exec $BINPATH --emperor /opt/uwsgiApps/conf.d/ --logto $LOGTO

uWSGI emperor

One of many uWSGI configuration options

One master process

Many independent child processes

Each application has a config file

Touch or modify the config file to restart the application

uWSGI example config

vi /opt/uwsgiapps/conf.d/bottle-hello.xml:

<uwsgi><master>true</master><processes>1</processes><vaccum>true</vaccum><chmod-socket>600</chmod-socket><socket>/tmp/%n.sock</socket><uid>www-data</uid><gid>www-data</gid><pythonpath>/opt/uwsgiApps/apps/%n/src/</pythonpath><module>scatterapp</module>

</uwsgi>

nginx configuration

vi /etc/nginx/conf.d/subdomain1.domain.com.conf:

server {listen 80;server_name subdomain1.domain.com.conf;

location / {include uwsgi_params;uwsgi_pass unix://tmp/bottle-example.py;

}}

System overview

nginx acts as a reverse proxy

nginx redirects the requests based on the domain name or any other parameter (ip address, url path, cookies, etc)

uWSGI starts and stops the applications

bottle is used to program the application

Questions

Links

http://nginx.org/

http://uwsgi-docs.readthedocs.org/

http://bottlepy.org/