Python Lover(4)Django Doc - CSS and Deployment

Python Lover(4)Django Doc - CSS and Deployment

1. Easy Way to Serve the Static Files
Have the static resources under here
easypoll/polls/static/polls/style.css
li a {
    color: green;
}

Adding this on the html template, for example, index.html
{% load staticfiles %}

<link rel="stylesheet" type="text/css" href="{% static 'polls/style.css' %}" />

2. Deploying Django

I used to use nginx + fastcgi, fastcgi implementation is FLUP. I would like to try WSGI this time.(Python Web Server Gateway Interface)

2.1 Choose to Try gunicorn
Install pip first
https://pip.pypa.io/en/latest/installing.html#install-or-upgrade-pip

>wget https://bootstrap.pypa.io/get-pip.py
>sudo python get-pip.py
Password: Requirement already up-to-date: pip in /Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages Cleaning up...

The problem is that when I install python, I only soft link the python command. Actually I should link this directory to class path.
/Library/Frameworks/Python.framework/Versions/3.4/bin

Soft link in that directory
>sudo ln -s python3 python
>sudo ln -s pip3 pip

>pip -V
pip 1.5.6 from /Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages (python 3.4)

Install gunicorn
http://docs.gunicorn.org/en/latest/install.html

>pip install gunicorn
Downloading/unpacking gunicorn  Downloading gunicorn-19.1.1-py2.py3-none-any.whl (104kB): 104kB downloaded Installing collected packages: gunicorn Successfully installed gunicorn Cleaning up...

Install greenlet
>pip install greenlet

2 Options here
http://eventlet.net/
It uses epoll or kqueue or libevent for highly scalable non-blocking I/O
>pip install eventlet

http://gevent.org/
Fast event loop based on libev (epoll on Linux, kqueue on FreeBSD)
>pip install gevent

It runs on my machine
>gunicorn easypoll.wsgi

Settings 
http://docs.gunicorn.org/en/latest/settings.html#settings
http://docs.gunicorn.org/en/latest/configure.html

Example of the configuration file
https://github.com/rdegges/django-skel/blob/master/gunicorn.py.ini
https://github.com/benoitc/gunicorn/blob/master/examples/example_config.py

>sudo gunicorn -c gunicorn.py.ini easypoll.wsgi
my configuration file should be as follow:
>cat gunicorn.py.ini 
"""gunicorn WSGI server configuration."""

import multiprocessing

bind = "127.0.0.1:8000"

workers = multiprocessing.cpu_count() * 2 + 1


2.2 Install on ubuntu
Actually I should run it on ubuntu system or similar
>sudo apt-get install python-software-properties
>sudo apt-add-repository ppa:gunicorn/ppa
>sudo apt-get update

Not working on ubuntu14.04
>sudo add-apt-repository --remove ppa:gunicorn/ppa
>sudo apt-get install gunicorn

>sudo apt-get install python-pip

>sudo pip install greenlet
>sudo pip install eventlet
>sudo pip install gevent

>sudo gunicorn -c gunicorn.py.ini easypoll.wsgi

Error Message
ImportError: No module named django.core.wsgi

Solution:
>python -V
Python 2.7.6

>sudo rm -fr python
>sudo ln -s python3 python

Download the django package
>wget https://www.djangoproject.com/m/releases/1.7/Django-1.7.tar.gz

>sudo python setup.py install

Error Message
ImportError: No module named 'setuptools'

Solution:
Install setuptools
https://pypi.python.org/pypi/setuptools

>wget https://pypi.python.org/packages/source/s/setuptools/setuptools-5.7.tar.gz
>cd /home/carl/download/install/setuptools-5.7
>sudo python setup.py install

>cd /home/carl/download/install/Django-1.7
>sudo python setup.py install

Error Message
>gunicorn -c gunicorn.py.ini easypoll.wsgi
Traceback (most recent call last):  File "/usr/bin/gunicorn", line 5, in <module>    from pkg_resources import load_entry_point  File "<frozen importlib._bootstrap>", line 2214, in _find_and_load  File "<frozen importlib._bootstrap>", line 2203, in _find_and_load_unlocked  File "<frozen importlib._bootstrap>", line 1191, in _load_unlocked  File "<frozen importlib._bootstrap>", line 1161, in _load_backward_compatible  File "/usr/local/lib/python3.4/dist-packages/setuptools-5.7-py3.4.egg/pkg_resources.py", line 2872, in <module>  File "/usr/local/lib/python3.4/dist-packages/setuptools-5.7-py3.4.egg/pkg_resources.py", line 449, in _build_master  File "/usr/local/lib/python3.4/dist-packages/setuptools-5.7-py3.4.egg/pkg_resources.py", line 745, in require  File "/usr/local/lib/python3.4/dist-packages/setuptools-5.7-py3.4.egg/pkg_resources.py", line 639, in resolve pkg_resources.DistributionNotFound: gunicorn==17.5

Solution:
>sudo easy_install --upgrade pip
>sudo apt-get install python3.4-dev

>sudo pip install greenlet
>sudo pip install eventlet
>sudo pip install gevent

Should install Gunicorn like this.
>sudo pip install git+https://github.com/benoitc/gunicorn.git

>sudo apt-get install python3-pip

It works then.
>gunicorn -c gunicorn.py.ini easypoll.wsgi

But when I visit the admin page, I get some problem with the static pages.

Static Configuration on easypoll/settings.py
# Static files (CSS, JavaScript, Images)

# https://docs.djangoproject.com/en/1.7/howto/static-files/

STATIC_URL = '/static/'

STATIC_ROOT = "/home/carl/work/easy/easypoll/static/"

STATICFILES_FINDERS = ( 'django.contrib.staticfiles.finders.AppDirectoriesFinder', 'django.contrib.staticfiles.finders.FileSystemFinder', )

Copy and Collect all the static files to directly
>python manage.py collectstatic

We can point the nginx to that place if we want.

Command to clean the PYC files.
>pyclean .

 

Finally, I found it is fine to using python 2.7.6.

And we can change the conf file like this.
carl@ubuntu-slave2:~/work/easy/easypoll$ cat gunicorn.py.ini

"""gunicorn WSGI server configuration."""

import multiprocessing

bind = "0.0.0.0:8000"

workers = multiprocessing.cpu_count() * 2 + 1

#worker_class = 'eventlet'

#worker_class = 'sync'

worker_class = 'gevent'

References:
More Topic
https://docs.djangoproject.com/en/1.7/topics/

Look and Feel
https://docs.djangoproject.com/en/1.7/intro/tutorial06/

How to deploy
https://docs.djangoproject.com/en/1.7/howto/deployment/

Spawn-fcgi, wsgi, fastcgi, cgi
http://lihuipeng.blog.51cto.com/3064864/890573
http://sillycat.iteye.com/blog/582074
http://lutaf.com/141.htm

http://docs.gunicorn.org/en/latest/deploy.html
https://pip.pypa.io/en/latest/installing.html#install-or-upgrade-pip
http://stackoverflow.com/questions/20181121/django-admin-not-working-ugly-serving-with-nginx-and-gunicorn