I have been running into this problem for a short while now and simply can't find a solution anywhere. I am using Google App Engine to run a default Python 2.7 app with Django 1.5 (via GAE SDK) created through PyCharm. I can upload the app successfully, but upon visiting the actual page, I get a Server Error. Then, checking the logs in Google App Engine, I see this:
ImportError: <module 'main' from '/base/data/home/apps/s~eloquent-ratio-109701/1.388053784931450315/main.pyc'> has no attribute application
After searching the internet for a while, I was able to find a few posts which address this issue, but attempting them never seemed to solve my problem. For example: This problem was solved by replacing "application" with "app" in the following lines:
application = django.core.handlers.wsgi.WSGIHandler()
util.run_wsgi_app(application)
In fact, I had run into this same issue before and this solution provided a fix for me in the past, however at that time I was running a separate app and it was not through the GAE.
I checked the Django documentation for version 1.5 here, but the code and suggestions there don't seem to conflict with what I currently have in my project.
I read a bit more about this type of problem, and saw another post that suggested checking the app's wsgi.py file to ensure that it is named 'application' or 'app' respectively, so that one could then use that same name throughout the rest of the application. However, upon checking those settings I saw that 'application' was used there too:
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
There's even a line in settings.py which uses the same nomenclature to declare the WSGI application:
WSGI_APPLICATION = 'Chimera.wsgi.application'
I'm really having trouble debugging this. I get the feeling it's really dumb and I just can't see it, but unfortunately I'm not particularly good at this kind of stuff -- I'm still a bit of a novice in this field.
Does anyone have any idea what I could try in an attempt to fix this issue?
UPDATE: I started making line by line changes and testing things, and eventually I found that the GAE log changes depending on the input for the "script" under app.yaml. So if I change the script under "handlers" between "main.app" and "main.application", it adjusts the log output to refer to "app" or "application" respectively. So that line in the app.yaml file tells the app what to look for, but I'm still not seeing why it can't be found. Not sure what else I could change to test it out. I wish I knew a bit more about the actual inner workings so that I could figure out why the app is confused about the attribute. Is it trying to run before it even gets instantiated or something?
Source code below:
main.py
import os, sys
os.environ['DJANGO_SETTINGS_MODULE'] = 'Chimera.settings'
from google.appengine.ext.webapp import util
from django.conf import settings
settings._target = None
import django.core.handlers.wsgi
import django.core.signals
import django.db
import django.dispatch.dispatcher
def main():
application = django.core.handlers.wsgi.WSGIHandler()
util.run_wsgi_app(application)
if __name__ == '__main__':
main()
app.yaml
application: eloquent-ratio-109701
version: 1
runtime: python27
api_version: 1
threadsafe: true
handlers:
- url: /.*
script: main.application
libraries:
- name: django
version: 1.5
wsgi.py
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "Chimera.settings")
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
Full log from GAE:
Traceback (most recent call last):
File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 240, in Handle
handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 302, in _LoadHandler
raise err
ImportError: <module 'main' from '/base/data/home/apps/s~eloquent-ratio-109701/1.388053784931450315/main.pyc'> has no attribute application
Thanks for helping me out.
In your main.py file (i.e. the main module) application is a variable inside the main() function, not an attribute of the main module. Basically you don't need a main() function.
GAE has some specific support for using Django, I'd strongly suggest going through the Django Support documentation and the Django App example.
Based on the comment made by #DanielRoseman I discovered that declaring the app inside of the main() function caused an issue because the app attribute was then only accessible at the main() function level, as it was a member variable of main() as opposed to a global variable. Although the default application files were structured this way by PyCharm, it seems that it was incorrect. I'm not sure if this is a compatibility issue, but regardless, moving the app declaration outside of the main() function adjusts the scope in a way which allows for other parts of the project to access it, solving my problem.
Thank you #DanielRoseman for the comment.
Related
I m new to django. I created a web with dajngo,and successfully deployed it in the server
The python app has been successfully setup and virtual environment has been setup.
but while running the web it gives me "Server Error (500)" I don't know whats the problem.
I think error is in "wsgi.py" file but i'm unable to idenify it.
My wsgi file:
import os
from django.core.wsgi import get_wsgi_application
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'karan_web.settings')
application = get_wsgi_application()
my "passenger_wsgi.py" file is:
import imp
import os
import sys
sys.path.insert(0, os.path.dirname(__file__))
wsgi = imp.load_source('wsgi', 'karan_web/wsgi.py')
application = wsgi.application
can someone help me with it;
Sorry for the late answer, I had figured out the as to this just forgot to post it.
As I stated in my question, the actual problem was in passenger_wsgi.py, the django server starts with the wsgi.py and act as the gate way to the Django server.
So whenever a Django project is uploaded on the hosting server, It creates a passenger_wsgi.py file and one default wsgi.py, address of which is provided in passenger_wsgi.py by default.
So we just need to change that address and provide the address of our own wsgi.py in the project
In my case it was
import os
import sys
from karan_web import wsgi
application = wsgi.application
just edit in passenger_wsgi.py the following code.
from karan_web.wsgi import application
You need to check if your code syntax is correct and running properly. If its still doesn't work try to delete and recreate your database in cpanel and check if you have made all necessary migrations, don't forget to restart your python app. If after all these it still doesn't work check if all your files have the correct file permission(766).
Deploying my django website with S3 as storage which runs fine locally to pythonanywhere gives a strange error I can't google a solution for:
"TypeError: a bytes-like object is required, not 'str'"
What I'm doing wrong?
I've tried to put my environment variables out of settings.env (aws keys, secret_key, etc) ad set them directly in my settings.py app. + every suggestion I could find but it's still the same :(
here's my /var/www/username_pythonanywhere_com_wsgi.py:
# +++++++++++ DJANGO +++++++++++
# To use your own Django app use code like this:
import os
import sys
from dotenv import load_dotenv
project_folder = os.path.expanduser('~/portfolio_pa/WEB') # adjust as appropriate
load_dotenv(os.path.join(project_folder, 'settings.env'))
# assuming your Django settings file is at '/home/myusername/mysite/mysite/settings.py'
path = '/home/corebots/portfolio_pa'
if path not in sys.path:
sys.path.insert(0, path)
os.environ['DJANGO_SETTINGS_MODULE'] = 'WEB.settings'
## Uncomment the lines below depending on your Django version
###### then, for Django >=1.5:
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
###### or, for older Django <=1.4
#import django.core.handlers.wsgi
#application = django.core.handlers.wsgi.WSGIHandler()
I'd expect the website to run fine just like it does locally.
Boto library doesn't have a good Python3 support. This particular issue is known in the boto bugtracker: https://github.com/boto/boto/issues/3837
The best way of fixing this is to use boto3 which has decent Python3 support and is a generally most supported AWS SDK for Python.
The reason why it works on your local machine and doesn't work on production is that pythonanywhere setup seems to be using proxy which triggers this incompatible boto code. See the actual calling code: https://github.com/boto/boto/blob/master/boto/connection.py#L747
Your error traceback confirms this.
Unfortunately, I'm not familliar with the django-photologue, but a brief look doesn't suggest that it strongly depends on boto3. Maybe I'm wrong.
I still think that the best way is to go with boto3. As a backup strat you can fork boto with a fix for this issue and install that instead of the official one from PyPI: https://github.com/boto/boto/pull/3699
I'm trying to separate out Django's secret key and DB pass into environmental variables, as widely suggested, so I can use identical code bases between local/production servers.
The problem I am running into is correctly setting and then reading the environmental vars on the production server running Apache + mod_wsgi.
Vars set in my user profile aren't available because Apache isn't run as that user. Vars set in the Virtual Hosts file with SetEnv are not available because the scope is somehow different.
I've read a couple 1,2 of SO answers, which leads to this blog with a solution.
I can't figure out how to apply the solution to current versions of Django which use a wsgi.py file, which looks like:
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
How can I apply that blog solution to the wsgi.py file, or is there a better place to store env-vars where Django can get at them?
If anyone else is frustrated by Graham's answer, here is a solution that actually works for the original question. I personally find setting environmental variables from Apache to be extremely useful and practical, especially since I configure my own hosting environment and can do whatever I want.
wsgi.py (tested in Django 1.5.4)
from django.core.handlers.wsgi import WSGIHandler
class WSGIEnvironment(WSGIHandler):
def __call__(self, environ, start_response):
os.environ['SETTINGS_CONFIG'] = environ['SETTINGS_CONFIG']
return super(WSGIEnvironment, self).__call__(environ, start_response)
application = WSGIEnvironment()
Of minor note, you lose the future-proof method of django.core.wsgi.get_wsgi_application, which currently only returns WSGIHandler(). If the WSGIHandler.__call__ method is ever updated and you update Django also, you may have to update the WSGIEnvironment class if the arguments change. I consider this a very small penalty to pay for the convenience.
FWIW. Relying on environment variables for fine grained configuration settings are in general not a good idea. This is because not all WSGI hosting environments or commercial PaaS offerings support the concept. Using environment variables for fine grained settings can also effectively lock you into a specific PaaS offering where you have directly embedded a lookup of a specifically named environment variable directly into your code, where the naming convention of that environment variable is specific to that hosting service. So although use of environment variables is pushed by certain services, always be careful of being dependent on environment variables as it will reduce the portability of your WSGI application and make it harder to move between deployment mechanisms.
That all said, the blog post you mention will not usually help. This is because it is using the nasty trick of setting the process environment variables on each request based on the per request WSGI environ settings set using SetEnv in Apache. This can cause various issues in a multi threading configuration if the values of the environment variables can differ based on URL context. For the case of Django, it isn't helpful because the Django settings module would normally be imported before any requests had been handled, which means that the environment variables would not be available at the time required.
This whole area of deployment configuration is in dire need of a better way of doing things, but frankly it is mostly a lost cause because hosting services will not change things to accommodate a better WSGI deployment strategy. They have done their work, have their customers locked into the way they have done it already and aren't about to create work for themselves and change things even if a better way existed.
Anyway, 'all problems in computer science can be solved by another level of indirection'. (http://en.wikipedia.org/wiki/Indirection) and that is what you can do here.
Don't have your application lookup environment variables. Have it import a deployment specific Python configuration module which contains a means of using an API to get the configuration settings. This configuration module would implement different ways of getting the actual settings based on the deployment mechanism. In some cases it could grab the values from environment variables. For other such as with Apache/mod_wsgi, the values could be in that configuration module, or read from a separate configuration file which could be an ini, json or yaml format. In providing a API, it can also map names of configuration settings to different names used by different PaaS offerings.
This configuration module doesn't need to be a part of your application code, but could be manually place into a subdirectory of '/etc/' on the target system. You just then need to set the Python module search path so your application can see it. The whole system could be made quite elegant as part of a wider better standard for WSGI deployment, but as I said, little incentive to do the hard work of creating such a thing when existing PaaS offerings are highly unlikely to change to use such a standard.
Here's an alternative solution that's as future-proof as get_wsgi_application. It even lets you set environment variables to use in your Django initialization.
# in wsgi.py
KEYS_TO_LOAD = [
# A list of the keys you'd like to load from the WSGI environ
# into os.environ
]
def loading_app(wsgi_environ, start_response):
global real_app
import os
for key in KEYS_TO_LOAD:
try:
os.environ[key] = wsgi_environ[key]
except KeyError:
# The WSGI environment doesn't have the key
pass
from django.core.wsgi import get_wsgi_application
real_app = get_wsgi_application()
return real_app(wsgi_environ, start_response)
real_app = loading_app
application = lambda env, start: real_app(env, start)
I'm not 100% clear how mod_wsgi manages its processes, but I assume it doesn't re-load the WSGI app very often. If so, the performance penalty from initializing Django will only happen once, inside the first request.
Alternatively, if you don't need to set the environment variables before initializing Django, you can use the following :
# in wsgi.py
KEYS_TO_LOAD = [
# A list of the keys you'd like to load from the WSGI environ
# into os.environ
]
from django.core.wsgi import get_wsgi_application
django_app = get_wsgi_application()
def loading_app(wsgi_environ, start_response):
global real_app
import os
for key in KEYS_TO_LOAD:
try:
os.environ[key] = wsgi_environ[key]
except KeyError:
# The WSGI environment doesn't have the key
pass
real_app = django_app
return real_app(wsgi_environ, start_response)
real_app = loading_app
application = lambda env, start: real_app(env, start)
For Django 1.11:
Apache config:
<VirtualHost *:80 >
...
SetEnv VAR_NAME VAR_VALUE
</VirtualHost>
wsgi.py:
import os
import django
from django.core.handlers.wsgi import WSGIHandler
class WSGIEnvironment(WSGIHandler):
def __call__(self, environ, start_response):
os.environ["VAR_NAME"] = environ.get("VAR_NAME", "")
return super(WSGIEnvironment, self).__call__(environ, start_response)
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")
django.setup(set_prefix=False)
application = WSGIEnvironment()
I ran into the same problem of separating production and development code while tracking both of them into version control. I solved the problem using different wsgi scripts, one for production server and one for development server. Create two different setting files as mentioned here. And reference them in wsgi scripts. For example the following is wsgi_production.py file
...
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings.production")
...
and in wsgi_development.py file
...
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings.development")
...
I seem to have run into a bit of an issue.
I am busy creating an app, and over the last few weeks setup my server to use Git, mod_wsgi to host this app.
Since deploying it, everything seems to be running smoothly however, I had to go through all my files and insert the absolute url of the project to make sure it works fine.
on my local machine
from registration.models import UserRegistration
on server
from myapp.registration.models import UserRegistration
Am I doing something wrong?
And this has also caused an issue for me where I cannot access my django admin interface.
All i get is this: Caught an exception while rendering: No module named registration
Exception Value: Caught an exception while rendering: No module named registration
As far as I am concerned my app has all the relevant urls, but it does not seem to work.
Thank you in advance
The problem is occurring because somehow your local machine is adding the myapp directory to the PYTHONPATH, as well as its parent directory. The way to fix this is to modify your .wsgi script to add both these directories to sys.path:
import sys
sys.path.insert(0, '/path/to/parent')
sys.path.insert(0, '/path/to/parent/myapp')
Read and use improved WSGI script in:
http://blog.dscpl.com.au/2010/03/improved-wsgi-script-for-use-with.html
This will set up environment to better match Django built in development server and you shoud hopefully not see a difference between the two, especially in respect of how Python module search path is handled.
I am trying to setup django with fastcgi on apache. Django is installed and seems to be running correctly but I am having problems with setting up fastcgi.
I decided to test out my dispatch.fcgi script in the interactive python shell line by line and the following line:
from django.core.servers.fastcgi import runfastcgi
results in the following error:
ImportError: No module named core.servers.fastcgi
I can import django with no problem but import django.core gives yet another ImportError (No module named core).
How can I go about ensuring that I can import django.core. If I can import django then in must be on my path, and so why can I not import core?
You probably have a file/folder called django somewhere in your path, that isn't the actual path.
try this
import sys
sys.path
And then check everything in that output to see if there is a file/folder called django(.py) somewhere.
If so, change the path (sys.path = ['/path/to/directory/below/django/install'] + sys.path) or move/rename the file.
Probably you have django.py module in your working directory or in any other that is in python path.
For anyone having this problem and coming across this question like I did, it turns out that fastcgi support has been removed as of Django 1.9, thus you will get this import error if trying to import it. Refer Using Django with virtualenv, get error ImportError: No module named 'django.core.servers.fastcgi'