DJANGO-REST, MOD_WSGI and APACHE integration problems - apache

Question

I've been trying to integrate a DJANGO-REST WS into apache using MOD_WSGI, but after some long hours of trying to apply all debugging techniques and different wsgi scripts, I would appreciate some help.
Server version: Apache/2.2.22 (Ubuntu)
Python 2.7.3 (default, Feb 27 2014, 19:58:35)
MOD_WSGI Version: 3.3
Currently my WSGI file is the following:
"""
WSGI config for zighome_rest project.
It exposes the WSGI callable as a module-level variable named ``application``.
For more information on this file, see
https://docs.djangoproject.com/en/1.6/howto/deployment/wsgi/
"""
import os, sys
sys.path.append('/usr/local/ZigHomeWS')
sys.path.append('/usr/local/ZigHomeWS/zighome_rest')
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "zighome_rest.settings")
import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()
and my virtual host is configured as below:
<VirtualHost *:80>
ServerAdmin my.email#gmail.com
ServerName my.server.name
DocumentRoot /usr/local/DummyApp
WSGIDaemonProcess ZigHomeWS python-path=/usr/local/ZigHomeWS/zighome_rest:/usr/lib/python2.7:/usr/local/lib/python2.7/site-packages/django
WSGIProcessGroup ZigHomeWS
WSGIApplicationGroup %{GLOBAL}
WSGIScriptAlias /ZigHomeWS /usr/local/ZigHomeWS/zighome_rest/zighome_rest/WSGI/django.wsgi
WSGIPassAuthorization On
<Directory /usr/local/ZigHomeWS/zighome_rest>
<Files django.wsgi>
Order deny,allow
Allow from all
</Files>
</Directory>
<Directory /usr/local/DummyApp>
Order deny,allow
Allow from all
</Directory>
ErrorLog /var/log/apache2/error_ZigHomeWS.log
# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
LogLevel info
</VirtualHost>
The current settings.py file has the following configuration:
"""
Django settings for zighome_rest project.
For more information on this file, see
https://docs.djangoproject.com/en/1.6/topics/settings/
For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.6/ref/settings/
"""
# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os
BASE_DIR = os.path.dirname(os.path.dirname(__file__))
# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.6/howto/deployment/checklist/
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '6h34&#m=1t4!(axkhz1+%6%u8^o(7^ao500pl#*+=$sk(a846#'
# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True
TEMPLATE_DEBUG = True
ALLOWED_HOSTS = []
# Application definition
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'rest_framework',
'configuration',
'execution',
)
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
)
ROOT_URLCONF = 'zighome_rest.urls'
WSGI_APPLICATION = 'zighome_rest.wsgi.application'
# Database
# https://docs.djangoproject.com/en/1.6/ref/settings/#databases
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': '/usr/local/ZigHomeWS/zighome_rest/zighome.db',
'USER': '',
'PASSWORD': '',
'HOST': '',
'PORT': '',
}
}
# Internationalization
# https://docs.djangoproject.com/en/1.6/topics/i18n/
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_L10N = True
USE_TZ = True
# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.6/howto/static-files/
STATIC_URL = '/static/'
As soon as I call one of the services, with curl, like so:
curl -X POST http://my.server.name/ZigHomeWS/execution/start/ -u user:passwd
I get the following error logged:
[Sat Sep 27 19:15:28 2014] [info] mod_wsgi (pid=13351): Adding '/usr/local/ZigHomeWS/zighome_rest' to path.
[Sat Sep 27 19:15:28 2014] [info] mod_wsgi (pid=13351): Adding '/usr/lib/python2.7' to path.
[Sat Sep 27 19:15:28 2014] [info] mod_wsgi (pid=13351): Adding '/usr/local/lib/python2.7/site-packages/django' to path.
[Sat Sep 27 19:15:32 2014] [info] [client 46.189.221.224] mod_wsgi (pid=13351, process='ZigHomeWS', application=''): Loading WSGI script '/usr/local/ZigHomeWS/zighome_rest/zighome_rest/WSGI/django.wsgi'.
[Sat Sep 27 18:15:33 2014] [error] No handlers could be found for logger "django.request"
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] mod_wsgi (pid=13351): Exception occurred processing WSGI script '/usr/local/ZigHomeWS/zighome_rest/zighome_rest/WSGI/django.wsgi'.
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] Traceback (most recent call last):
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/wsgi.py", line 187, in __call__
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] response = self.get_response(request)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py", line 199, in get_response
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] response = self.handle_uncaught_exception(request, resolver, sys.exc_info())
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py", line 236, in handle_uncaught_exception
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return debug.technical_500_response(request, *exc_info)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/views/debug.py", line 91, in technical_500_response
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] html = reporter.get_traceback_html()
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/views/debug.py", line 350, in get_traceback_html
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return t.render(c)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/base.py", line 148, in render
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return self._render(context)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/base.py", line 142, in _render
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return self.nodelist.render(context)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/base.py", line 844, in render
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] bit = self.render_node(node, context)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py", line 80, in render_node
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return node.render(context)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py", line 90, in render
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] output = self.filter_expression.resolve(context)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/base.py", line 624, in resolve
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] new_obj = func(obj, *arg_vals)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/template/defaultfilters.py", line 769, in date
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return format(value, arg)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/dateformat.py", line 343, in format
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return df.format(format_string)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/dateformat.py", line 35, in format
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] pieces.append(force_text(getattr(self, piece)()))
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/dateformat.py", line 268, in r
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return self.format('D, j M Y H:i:s O')
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/dateformat.py", line 35, in format
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] pieces.append(force_text(getattr(self, piece)()))
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/encoding.py", line 85, in force_text
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] s = six.text_type(s)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/functional.py", line 144, in __text_cast
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return func(*self.__args, **self.__kw)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/translation/__init__.py", line 83, in ugettext
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return _trans.ugettext(message)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/translation/trans_real.py", line 325, in ugettext
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] return do_translate(message, 'ugettext')
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/translation/trans_real.py", line 306, in do_translate
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] _default = translation(settings.LANGUAGE_CODE)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/translation/trans_real.py", line 209, in translation
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] default_translation = _fetch(settings.LANGUAGE_CODE)
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] File "/usr/local/lib/python2.7/dist-packages/django/utils/translation/trans_real.py", line 189, in _fetch
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] "The translation infrastructure cannot be initialized before the "
[Sat Sep 27 18:15:33 2014] [error] [client 46.189.221.224] AppRegistryNotReady: The translation infrastructure cannot be initialized before the apps registry is ready. Check that you don't make non-lazy gettext calls at import time.
I must confess that adding "/usr/local/lib/python2.7/site-packages/django" was just a measure of desperation, which end-up by resulting on nothing.
One thing I should probably mention, although it shouldn't make any difference to the solution, is that the core system is actually a C++ system which I wrapped up with SWIG.
Needless to say, it's working on the Django-REST development environment.
Last but not least, if in the WSGI script file I change these two lines:
import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()
by these:
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
It will crash instead of providing the stack trace in the log file:
[Sat Sep 27 19:44:10 2014] [error] [client X.X.X.X] Premature end of script headers: django.wsgi
I end up applying the recommended debugging techniques but unfortunately it wasn't very helpful, since the stack-trace of gdb just gave me:
(gdb) cont
Continuing.
[New Thread 0x7fc6d4de9700 (LWP 9312)]
[New Thread 0x7fc6d45e8700 (LWP 9313)]
[Thread 0x7fc6dde3a700 (LWP 9242) exited]
[Thread 0x7fc6d45e8700 (LWP 9313) exited]
[Thread 0x7fc6d4de9700 (LWP 9312) exited]
[Thread 0x7fc6dd639700 (LWP 9245) exited]
[Thread 0x7fc6e364a740 (LWP 9216) exited]
[Inferior 1 (process 9216) exited with code 01]
Investigation:
So... I've just realized something.
From what I read from several sites on the web, I should be really using this call:
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
on the WSGI script. Since I was getting nowhere fast with these two lines of code, which were crashing all the time, I remembered to call any other web-service that I have created and VOILA!! It works. (Don't know why I haven't try this before...stubbornness I guess)
Now, one of the major differences between the two web-services, is that one, only parses some XML file and adds data to the sqlite3 database and the other one (the one that crashes), starts the whole system, which implies the creation of multiple threads and so forth.
Thus, I'm now looking for any threads related documented issue I can find with modwsgi.
I hope you can provide me with some help
Thank you

Answer 1

I've updated my wsgi.py file from:
from django.core.handlers.wsgi import WSGIHandler
application = WSGIHandler()
To:
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()