Django Invalid HTTP_HOST header: 'testserver'. You may need to add u'testserver' to ALLOWED_HOSTS

Question

I started learning Django, I’m in the middle of implementing “Test a view” functionality.
When I use test Client in the shell, the exception has occurred as follows.

Invalid HTTP_HOST header: ‘testserver’. You may need to add u’testserver’ to ALLOWED_HOSTS.

I run the command in the shell as follows.

>>> from django.test.utils import setup_test_environment
>>> setup_test_environment()
>>> from django.test import Client
>>> client = Client()
>>> response = client.get('/')
>>> response.status_code
400

In the tutorial, 404 should be appeared, but I get 400.
When I continue running the command as follows, same exception has occurred.

>>> response = client.get(reverse('polls:index'))
>>> response.status_code
400

but the result must be 200.I guess I should declare ALLOWED_HOSTS in the settings.py, but how can I?
I run the server on localhost using $python manage.py runserver.

I wanna know the reason and solution.

Here is settings.py as follows.

import os
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
SECRET_KEY = '8v57o6wyupthi^#41_yfg4vsx6s($1$x0xmu*95_u93wwy0_&u'
DEBUG = True
ALLOWED_HOSTS = [127.0.0.1,'localhost']
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'polls',
]
....    (MIDDLEWARE)
ROOT_URLCONF = 'tutorial.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'tutorial.wsgi.application'
....    (DATABASES, AUTH_PASSWORD_VALIDATORS)
LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

Asked By: Yuiry Kozlenko

||

Source

Answer 1

Edit the following line in your settings.py file:

ALLOWED_HOSTS = ['127.0.0.1', 'localhost']

Restart your server afterwards

Answered By: Exprator

Answer 2

ALLOWED_HOSTS = ['XXX.iptime.org', 'localhost', '127.0.0.1', 'testserver']


# Application definition

INSTALLED_APPS = [
    'polls.apps.PollsConfig',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

Answered By: khjoony

Answer 3

You should edit it like that:

ALLOWED_HOSTS = [
‘127.0.0.1’,
‘localhost’,
‘testserver’,
]

Answered By: Oussama Boumaad

Answer 4

settings.py is in read-only mode

ALLOWED_HOSTS = ['127.0.0.1', 'localhost']

this is how to save it

Answered By: Muhammad Shahid Rafi

Answer 5

Apart from the correct answers, there is an important check which you need to keep in mind. Setting ALLOWED_HOSTS with a single valued tuple will still give you same error, for example if you set it this way:

ALLOWED_HOSTS=('testserver')

It does not work, because you may wanted to make this a tuple but ACTUALLY it is a string in Python, yes thats strange but true! you can read more about tuples here: tuples.

If you want to make it a tuple, you need to add a comma like this:

ALLOWED_HOSTS=('testserver',)

This works as expected.

Answered By: Haziq

Answer 6

You can try for testing purpose

ALLOWED_HOSTS = ['*']

Answered By: Amit Panasara

Answer 7

Adding ‘testserver’, ‘localhost’, or ‘127.0.0.1’ did not work for me (Django >3.1).

What did was initiating the client with a different server name:

c = Client(SERVER_NAME='localhost')

Note that I got an error mentioning I needed to add ‘testserver’, but that I initiate the client with ‘localhost’.

Answered By: Raoul

Answer 8

This worked for me
you can try this:

ALLOWED_HOSTS += ['testserver']

Answered By: CodeView

Answer 9

In settings.py file, you can simply update ALLOWED_HOSTS = ['*']. But yes, you can also use solutions provided by others too but to keep it short and simple you can go with this

Answered By: Rajeshwar Sharma

Django Invalid HTTP_HOST header: 'testserver'. You may need to add u'testserver' to ALLOWED_HOSTS

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