Hosting flask with mod_wsgi, Apache

Question

I've written a small app in Flask, and I'm trying to get it to work on a Linode server. But currently, if I enter the server IP address in my browser, I get a list of files.

I have python installed not in a virtualenv (currently), checked, it's working.

I've been mostly following this tutorial: https://www.digitalocean.com/community/articles/how-to-deploy-a-flask-application-on-an-ubuntu-vps

My app structure is this (the top folder is located in /var/www/):

|--mythmuff/
|----mythmuff/
|------__init__.py
|------app.db
|------config.py
|------models.py
|------templates/
|--------index.html
|------views.py
|--mythmuff.wsgi

Here's my init.py:

from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy
from flask.ext.mail import Mail
import os
basedir = os.path.abspath(os.path.dirname(__file__))


app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'app.db')
# app email settings go here
mail = Mail(app)
db = SQLAlchemy(app)

import views
import models

Here's my mythmuff.wsgi:

import sys
sys.path.insert(0, '/var/www/mythmuff')
from mythmuff import app as application

And here's my /etc/apache2/sites-available/mythmuff.ru.conf (I 'pointed' Apache to the file).

<VirtualHost *:80>
    ServerName mythmuff.ru

    WSGIDaemonProcess mythmuff user=www-data group=www-data threads=5
    WSGIScriptAlias / /var/www/mythmuff/mythmuff.wsgi

    <Directory var/www/mythmuff/mythmuff>
        Order allow,deny
        Allow from all
    </Directory>
    Alias /static /var/www/mythmuff/mythmuff/static
    <Directory /var/www/mythmuff/mythmuff/static>
        Order allow,deny
        Allow from all
    </Directory>
    ErrorLog ${APACHE_LOG_DIR}/error.log
    LogLevel warn
</VirtualHost>

I'm quite new in the area of setting up Apache/wsgi, but I think the fact that when I go to the IP address and get just a list of files and folders in the /var/www/ directory means that I'm missing an app.run() somewhere. I tried adding this to __init__.py:

if __name__ == "__main__":
    app.run()

But I get an error when running __init__.py on my home computer:

  File "/Users/georgeoblapenko/Dropbox/University/Python/flask/MythMuff/mythmuff/mythmuff/__init__.py", line 18, in <module>
    import views
  File "/Users/georgeoblapenko/Dropbox/University/Python/flask/MythMuff/mythmuff/mythmuff/views.py", line 5, in <module>
    from models import Product
  File "/Users/georgeoblapenko/Dropbox/University/Python/flask/MythMuff/mythmuff/mythmuff/models.py", line 6, in <module>
    class Product(db.Model):
  File "/Users/georgeoblapenko/anaconda/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 510, in __init__
    DeclarativeMeta.__init__(self, name, bases, d)
  File "/Users/georgeoblapenko/anaconda/lib/python2.7/site-packages/sqlalchemy/ext/declarative/api.py", line 53, in __init__
    _as_declarative(cls, classname, cls.__dict__)
  File "/Users/georgeoblapenko/anaconda/lib/python2.7/site-packages/sqlalchemy/ext/declarative/base.py", line 246, in _as_declarative
    **table_kw)
  File "/Users/georgeoblapenko/anaconda/lib/python2.7/site-packages/sqlalchemy/sql/schema.py", line 342, in __new__
    "existing Table object." % key)
sqlalchemy.exc.InvalidRequestError: Table 'product' is already defined for this MetaData instance.  Specify 'extend_existing=True' to redefine options and columns on an existing Table object.

At home, I ran a runserver.py script from the top mythmuff folder for testing (as documented here: http://flask.pocoo.org/docs/patterns/packages/).

So, what do I need to add to actually make the whole thing work?

Update: I decided to run a simple wsgi hello world test. So I replaced everything in mythmuff.wsgi with

import os
import sys
sys.path.append('/var/www/mythmuff/mythmuff')

def application(environ, start_response):
        status = '200 OK'
        output = 'Hello World!'

        response_headers = [('Content-type', 'text/plain'),
                                        ('Content-Length', str(len(output)))]
        start_response(status, response_headers)
        return [output]

However, I still get the files/folder list, instead of the "Hello World!" page. So it seems the request doesn't get passed to the WSGI for some reason.

Answer 1

OK, I managed to figure it out. Turns out, I deleted the default apache index.html file, and didn't disable the 000-default.conf (via dissite), so that's why it showing the folder. Everything works now.

Answer 2

Yeah. If you want to access the server via the external IP address, you have to disable the default site configuration first.

sudo a2dissite 000-default.conf
service apache2 restart