从虚拟环境运行Flask应用程序

Question

I have a simple flask app that i want to be accessible from internet. OS is debian7, and unfortunately it can't be changed.

What I did: - downloaded and installed Python3.4 into /usr/local/opt/python3.4.3 - installed wsgi lib for py3 - installed virtualenv and created new env in my flask project folder - installed flask together with some other packages that I need within this env - created VirtualHost as follows:

cat /etc/apache2/sites-available/Monitor
Listen 8080

<VirtualHost *:8080>
                ServerName {ip address}
                ServerAdmin {my email}
                WSGIScriptAlias / /var/www/Monitor/monitor.wsgi

                <Directory /var/www/Monitor/Monitor/>
                        Order allow,deny
                        Allow from all
                </Directory>

                Alias /static /var/www/Monitor/Monitor/static

                <Directory /var/www/Monitor/Monitor/static/>
                        Order allow,deny
                        Allow from all
                </Directory>

                ErrorLog ${APACHE_LOG_DIR}/error.log
                LogLevel warn
                CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

now when i try to access the app from the internet I see these errors in error.log

[Sat Nov 14 22:16:04 2015] [error] /usr/local/bin/python3
[Sat Nov 14 22:16:04 2015] [error] [client ip] mod_wsgi (pid=13450): Target WSGI script '/var/www/Monitor/monitor.wsgi' cannot be loaded as Python module.
[Sat Nov 14 22:16:04 2015] [error] [client ip] mod_wsgi (pid=13450): Exception occurred processing WSGI script '/var/www/Monitor/monitor.wsgi'.
[Sat Nov 14 22:16:04 2015] [error] [client ip] Traceback (most recent call last):
[Sat Nov 14 22:16:04 2015] [error] [client ip]   File "/var/www/Monitor/monitor.wsgi", line 21, in <module>
[Sat Nov 14 22:16:04 2015] [error] [client ip]     from Monitor import app as application
[Sat Nov 14 22:16:04 2015] [error] [client ip]   File "/var/www/Monitor/Monitor/__init__.py", line 4, in <module>
[Sat Nov 14 22:16:04 2015] [error] [client ip]     from flask import Flask, render_template, url_for
[Sat Nov 14 22:16:04 2015] [error] [client ip]   File "/var/www/Monitor/Monitor/venv/lib/python3.4/site-packages/flask/__init__.py", line 17, in <module>
[Sat Nov 14 22:16:04 2015] [error] [client ip]     from werkzeug.exceptions import abort
[Sat Nov 14 22:16:04 2015] [error] [client ip]   File "/var/www/Monitor/Monitor/venv/lib/python3.4/site-packages/werkzeug/__init__.py", line 152, in <module>
[Sat Nov 14 22:16:04 2015] [error] [client ip]     __import__('werkzeug.exceptions')
[Sat Nov 14 22:16:04 2015] [error] [client ip]   File "/var/www/Monitor/Monitor/venv/lib/python3.4/site-packages/werkzeug/exceptions.py", line 113
[Sat Nov 14 22:16:04 2015] [error] [client ip]     return u'<p>%s</p>' % escape(self.description)
[Sat Nov 14 22:16:04 2015] [error] [client ip]                       ^
[Sat Nov 14 22:16:04 2015] [error] [client ip] SyntaxError: invalid syntax

From what I could find in the internet, such errors appear when trying to start flask app with python version <= 3.3, which is not my case I think (how do i check?)

here is my wsgi that starts the app

#!/usr/bin/env python3

import os
import sys
import logging


logging.basicConfig(stream=sys.stderr)

PROJECT_DIR = '/var/www/Monitor/'
sys.path.insert(0, PROJECT_DIR)

def execfile(filename):
    globals = dict(__file__ = filename)
    exec(open(filename).read(), globals)


activate_this = '/var/www/Monitor/Monitor/venv/bin/activate_this.py'
execfile(activate_this)

from Monitor import app as application

Any help would be very much appreciated. Any additional information will be supplied if necessary.

Answer 1

Default Python3 on Debian 7 is 3.2.3, libapache2-mod-wsgi is in version 3.3.

You Apache run Your app with default Python because mod-wsgi has to be compiled against one and only one python version (in this case python 3.3).

mod-wsgi 3.3

If You want to run only one app (or many apps) with Python 3.4, try to recompile mod-wsgi with python 3.4

mod-wsgi 4.1.x or newer

This newer version of mod_wsgi provides a way of installing mod_wsgi against multiple Python versions and running up an Apache instance for each using a provided script. The script takes over all the setup of the Apache configuration so you do not need to worry about it.

https://pypi.python.org/pypi/mod_wsgi

old answer

To change Python version, set in Apache conf:

WSGIPythonHome /usr/local/opt/python3.4.3/
WSGIPythonPath /var/www/Monitor:/var/www/Monitor/Monitor/venv/lib/python3.4/site-packages:/usr/local/opt/python3.4.3/lib/site-packages

for details read https://code.google.com/p/modwsgi/wiki/ConfigurationDirectives#WSGIPythonHome