nginx+gunicorn+django+aws bad request - django

Question

I was following a tutorial at https://ashokfernandez.wordpress.com/2014/03/11/deploying-a-django-app-to-amazon-aws-with-nginx-gunicorn-git/
on deploying a django application. This is my current situation:
fab spawn instance created the aws instance with nginx and gunicorn installed but when I tried accessing the site on that machine I got a 400 Bad Request. I checked the nginx-error log but that was empty and the nginx-access log showed that it had received the requests. The supervisor log had the following:
[2015-01-31 21:26:20 +0000] [15823] [INFO] Starting gunicorn 19.2.0
[2015-01-31 21:26:20 +0000] [15823] [INFO] Listening at: http://127.0.0.1:8002/ (15823)
[2015-01-31 21:26:20 +0000] [15823] [INFO] Using worker: sync
[2015-01-31 21:26:20 +0000] [15832] [INFO] Booting worker with pid: 15832
[2015-01-31 21:26:20 +0000] [15833] [INFO] Booting worker with pid: 15833
[2015-01-31 21:26:20 +0000] [15834] [INFO] Booting worker with pid: 15834
[2015-01-31 21:26:20 +0000] [15835] [INFO] Booting worker with pid: 15835
[2015-01-31 21:26:20 +0000] [15836] [INFO] Booting worker with pid: 15836
[2015-01-31 21:26:31 +0000] [15837] [INFO] Starting gunicorn 19.2.0
[2015-01-31 21:26:31 +0000] [15837] [ERROR] Connection in use: (‘127.0.0.1′, 8002)
[2015-01-31 21:26:31 +0000] [15837] [ERROR] Retrying in 1 second.
[2015-01-31 21:26:32 +0000] [15837] [ERROR] Connection in use: (‘127.0.0.1′, 8002)
[2015-01-31 21:26:32 +0000] [15837] [ERROR] Retrying in 1 second.
[2015-01-31 21:26:33 +0000] [15837] [ERROR] Connection in use: (‘127.0.0.1′, 8002)
[2015-01-31 21:26:33 +0000] [15837] [ERROR] Retrying in 1 second.
[2015-01-31 21:26:34 +0000] [15837] [ERROR] Connection in use: (‘127.0.0.1′, 8002)
[2015-01-31 21:26:34 +0000] [15837] [ERROR] Retrying in 1 second.
[2015-01-31 21:26:35 +0000] [15837] [ERROR] Connection in use: (‘127.0.0.1′, 8002)
[2015-01-31 21:26:35 +0000] [15837] [ERROR] Retrying in 1 second.
[2015-01-31 21:26:36 +0000] [15837] [ERROR] Can’t connect to (‘127.0.0.1′, 8002)
[2015-01-31 21:26:37 +0000] [15846] [INFO] Starting gunicorn 19.2.0
[2015-01-31 21:26:37 +0000] [15846] [INFO] Listening at: http://127.0.0.1:8002 (15846)
[2015-01-31 21:26:37 +0000] [15846] [INFO] Using worker: sync
[2015-01-31 21:26:37 +0000] [15855] [INFO] Booting worker with pid: 15855
[2015-01-31 21:26:37 +0000] [15856] [INFO] Booting worker with pid: 15856
[2015-01-31 21:26:37 +0000] [15857] [INFO] Booting worker with pid: 15857
[2015-01-31 21:26:38 +0000] [15858] [INFO] Booting worker with pid: 15858
[2015-01-31 21:26:38 +0000] [15859] [INFO] Booting worker with pid: 15859
I changed ALLOWED_HOSTS from [] to ["*"] and then '*'
When I changed it to the string, I got "The requested URL / was not found on this server." On other instances, I got 400 bad request.
This is the first time I am deploying a django app on nginx and I can’t figure out what the problem might be. Could you please help me debug this error?
Thanks in advance!!
PS: Please let me know if I need to post any config files. So far I have just followed the tutorial and I have not changed any configurations.
UPDATE:
common.py
import os
BASE_DIR = os.path.dirname(os.path.dirname(__file__))
SECRET_KEY = 'blah'
ALLOWED_HOSTS = []
# Application definition
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
)
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
)
ROOT_URLCONF = 'mosaic.urls'
WSGI_APPLICATION = 'mosaic.wsgi.application'
# Internationalization
# https://docs.djangoproject.com/en/1.7/topics/i18n/
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_L10N = True
USE_TZ = True
prod.py
from mosaic.settings.common import *
DEBUG = True #Change this after the project starts working
TEMPLATE_DEBUG = True
ALLOWED_HOSTS = []
# Database
# https://docs.djangoproject.com/en/1.6/ref/settings/#databases
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'mosaic',
'USER' : 'adminuser',
'PASSWORD' : '****',
'HOST' : 'abcd.cjcgmgnogsvc.us-west-1.rds.amazonaws.com',
'PORT' : '5432',
}
}
# Static files via Amazon S3 (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.6/howto/static-files/
INSTALLED_APPS += ('storages',)
AWS_STORAGE_BUCKET_NAME = "xyz"
STATICFILES_STORAGE = 'storages.backends.s3boto.S3BotoStorage'
S3_URL = 'http://%s.s3.amazonaws.com/' % AWS_STORAGE_BUCKET_NAME
STATIC_URL = S3_URL
Also in my project config files I have
fabconf['DOMAINS'] = ""
I thought this might be relevant as well

Answer 1

The allowed hosts has to match the host names you'll be using. So put the ALLOWED_HOSTS = [] in a settings file specific to your environment (Dev or production). On the dev side set it to ALLOWED_HOSTS = ['localhost', '127.0.0.1'] and on production set it go your domain & server IPs.
From the docs:
Values in this list can be fully qualified names (e.g. 'www.example.com'), in which case they will be matched against the request’s Host header exactly (case-insensitive, not including port). A value beginning with a period can be used as a subdomain wildcard: '.example.com' will match example.com, www.example.com, and any other subdomain of example.com. A value of '*' will match anything; in this case you are responsible to provide your own validation of the Host header (perhaps in a middleware; if so this middleware must be listed first in MIDDLEWARE_CLASSES).
The status 400 response you get is due to a SuspiciousOperation exception being raised when your host header doesn't match any values in that list.