133
votes

I'm using Django 1.6.5 with the setting:

DEBUG = True

When I change to DEBUG = False and run manage.py runserver, I get the following error:

CommandError: You must set settings.ALLOWED_HOSTS if DEBUG is False

I get the same error with the following setting:

ALLOWED_HOSTS = ['127.0.0.1', 'localhost']

How can I fix this?

11
Check if below you defined again DEBUG = True. It could be just a bad copypaste. I got here because I canceled DEBUG = False by accidentTms91

11 Answers

183
votes

Try

ALLOWED_HOSTS = ['*']

Less secure if you're not firewalled off or on a public LAN, but it's what I use and it works.

EDIT: Interestingly enough I've been needing to add this to a few of my 1.8 projects even when DEBUG = True. Very unsure why.

EDIT: This is due to a Django security update as mentioned in my comment.

65
votes

Your solution might be to add the original IP and/or hostname also:

ALLOWED_HOSTS = [
  'localhost',
  '127.0.0.1',
  '111.222.333.444',
  'mywebsite.com']

The condition to be satisfied is that the host header (or X-Forwarded-Host if USE_X_FORWARDED_HOST is enabled) should match one of the values in ALLOWED_HOSTS.

29
votes

Make sure it's not redefined again lower down in your settings.py. The default settings has:

ALLOWED_HOSTS = []

15
votes

From documentation: https://docs.djangoproject.com/en/1.10/ref/settings/

if DEBUG is False, you also need to properly set the ALLOWED_HOSTS setting. Failing to do so will result in all requests being returned as “Bad Request (400)”.

And from here: https://docs.djangoproject.com/en/1.10/ref/settings/#std:setting-ALLOWED_HOSTS

I am using something like this:

ALLOWED_HOSTS = ['localhost', '127.0.0.1', 'www.mysite.com']
5
votes

Use this:

ALLOWED_HOSTS =  ['localhost', '127.0.0.1']
1
votes

If you work in PyCharm, check the Environmental variables for your Django server. You should specify the proper module.settings file

1
votes

This works for me:

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = False

ALLOWED_HOSTS = ['localhost', '127.0.0.1']
0
votes

Try

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = ['*']

A value of '*' will match anything; in this case you are responsible to provide your own validation of the Host header.

0
votes

I also experienced this cmderror. After trying all the answers on here, I couldn't still figure out the problem, here is what I did:

  1. Cd into the project directory. e.g cd project-dir
  2. I migrated. e.g python manage.py migrate
  3. I created a super user. e.g python manage.py createsuperuser
  4. Enter the desired info like username, password, email etc
  5. You should get a "super user created successfully" response
  6. Now run the server. E.g python manage.py runserver
  7. Click on the URL displayed
  8. The URL on your browser should look like this, 127.0.0.1:8000/Quit
  9. Now edit the URL on your browser to this, 127.0.0.1:8000/admin
  10. You should see an administrative login page
  11. Login with the super user info you created earlier on
  12. You should be logged in to the Django administration
  13. Now click on "view site" at the top of the page
  14. You should see a page which shows "the install worked successfully..... Debug = True"
  15. Voila! your server is up and running
0
votes

I had set ALLOW_HOSTS, INTERNAL_IPS and DEBUG=TRUE

but still got this error. my problem was i had created a python package which its name was 'settings' in main app. and that package name interfered with 'settings.py' file.

-9
votes

Just simply comment out the line: ALLOWED_HOSTS = [...]