Django catches wrong url, have to fix regex - django

I ended up like
www.ww.mywebsite.com/ urls with google search results,
I asked in google groups and They pointed the obvious that, www.ww.mywebsite.com, shouldnt be a 200 ok response.
(r'^$', myview), this is how I catch a url for my homepage,
I dont think this problem occurs cause of my url patterns cause, as far as I know, url patterns for to catch trailing words. www.wwww.example.com/test/, there would be 'test' to be our word to process, what about this wwww staff before my website name?

In the fully qualified URL www.example.com/test/, the Django URL matching only looks at the /test/ part. Here you need to filter the domain names, for which the ALLOWED_HOSTS setting was introduced. For example you can put in settings.yml:
ALLOWED_HOSTS = ['mywebsite.com', 'www.mywebsite.com']
Alternatively, you can use a custom middleware to redirect the user to the canonical URL. This is a better solution if the non-canonical URLs should still be accessible to the users:
class CanonicalDomainRedirectMiddleware(object):
def process_request(self, request):
if request.get_host() == 'mywebsite.com':
return None
if request.is_secure():
protocol = 'https'
else:
protocol = 'http'
return HttpResponsePermanentRedirect('%s://%s/%s' % (
protocol, 'mywebsite.com', request.get_full_path)

Related

Misconfigured custom HTTP error templates in Django project (404,500)

I am in Django HTTP error codes hell. Would be great if an expert can help me out of my misconfiguration.
My Django project runs with nginx as a reverse proxy coupled to a gunicorn application server.
Requirement:
I want a custom Page not found template to render (i.e. 404) when a url pattern is entered that doesn't exist in my urls.py. Sounds simple enough, and is well documented.
I have already gone ahead and implemented this.
The Problem:
Assume example.com is my live project.
1) If I try to access https://example.com/asdfasdf (i.e. unmatched, random gibberish) on my production server, it displays the 500 template instead of 404.
2) Next, if I try to curl the said url pattern via curl -I https://example.com/asdfasdf/, I see 200 OK instead of 404 or 500. Wth?
3) Moreover, if I try the same behavior with Debug = True on localhost, 404 is returned correctly (both template and HTTP error code are in consonance).
These 3 behaviors are quite perplexing.
My configuration:
I created error_views.py and inserted it in the folder where I keep my regular views.py. This error file contains:
from django.shortcuts import render
def server_error(request):
return render(request, '500.html')
def not_found(request):
return render(request, '404.html')
def permission_denied(request):
return render(request, '404.html')
def bad_request(request):
return render(request, '404.html')
In my urls.py (kept in the same folder as settings.py), I added the following after all url patterns:
handler404 = 'my_app.error_views.not_found'
handler500 = 'my_app.error_views.server_error'
handler403 = 'my_app.error_views.permission_denied'
handler400 = 'my_app.error_views.bad_request'
I created 404.html and 500.html, and inserted them in the default /templates/ directory.
In settings.py, I have ALLOWED_HOSTS = ['*']
Lastly, my nginx conf dealing with this is as follows (placed within the server block in the virtual host file):
# Error pages
error_page 500 502 503 504 /500.html;
location = /500.html {
root /home/ubuntu/this_proj/project_dir/templates/;
}
location = /too_bad.svg {
root /home/ubuntu/this_proj/project_dir/static/img/;
}
All of this is fairly regular stuff and I'm missing what I've misconfigured here. Can an expert guide me out of this mess?
Thanks in advance, and please ask for more information in case warranted.
Note: I tried solutions provided in similar questions on SO here and here. Needless to say, those misconfigurations were very different, displaying none of the symptoms I'm seeing.
If you use a custom handler, you have to explicitly set the proper http status for the response object. If you don't set the status, the default is 200 OK.
def not_found(request):
return render(request, '404.html', status=404)

ExtJS 5 application + Django rest framework CORS error when changing URL of store

I am developing a ExtJS application that uses a Django-rest-framework service. I am using CORS headers to allow fetching the data from the service (https://github.com/OttoYiu/django-cors-headers).
What happens is that at a point in time I want to change the URL from the store. And when I do that I get the following error:
XMLHttpRequest cannot load http://10.98.0.241:8000/reacsearch/as?_dc=1418831884352&page=1&start=0&limit=25. The request was redirected to 'http://10.98.0.241:8000/reacsearch/as/?_dc=1418831884352&page=1&start=0&limit=25', which is disallowed for cross-origin requests that require preflight.
In the settings.oy I define the following properties for the CORS
CORS_ALLOW_METHODS = (
'GET',
'OPTIONS'
)
CORS_ORIGIN_ALLOW_ALL = True
This works fine when I use URLs to list all the elements in my database, however when I change the store for another URL I get the error above. Also the link works fine in the browser.
The store url change is made this way:
var store = Ext.getStore(storeName);
store.getProxy().setUrl(newURL);
store.load();
The difference between the views, is that the two that work on the application are viewsets, while the other is just a generic list
class Example1viewset(viewsets.ModelViewSet):
"""
API endpoing that allows metabolites to be viewed.
"""
queryset = examples1.objects.all()
serializer_class = Example1Serializer
class Example1SearchList(generics.ListAPIView):
serializer_class = Example1Serializer
def get_queryset(self):
queryset = Example.objects.all()
if 'attr' in self.kwargs:
queryset = queryset.filter(Q(attribute1__contains=self.kwargs['attr']) | Q(attribute2__contains=self.kwargs['abbr']))
return queryset
Like I mentioned both examples work fine in the browser (even accessing through other computers in the network), however in the application when changing the URL of the store I get the CORS error. Does anyone has any idea why this is happening?
Thank you.
Edit:
Just for clarification, the problem is not in changing the url of the store. As I tried to set those urls as defaults, but they are not working when accessing from the application.
My urls.py file:
router = routers.DefaultRouter()
router.register(r'example', views.Example1ViewSet)
# Wire up our API using automatic URL routing.
# Additionally, we include login URLs for the browsable API.
urlpatterns = [
url(r'^', include(router.urls)),
url(r'^reacsearch/(?P<attr>.+)/$', Example1SearchList.as_view()),
url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
Can it be that the problem is related with the fact that I am not adding the search list to the router?
Edit2
Problem solved since I was trying to fetch data from a different domain. I changed the type of store to jsonp in Extjs, and I also allowed my rest service to render data as jsonp.
Just a reminder if anyone comes accross this same problem, it is necessary to add ?format=jsonp to the store url:
http://my/url/?format=jsonp
Since it looks like an alternate solution was found, I'll explain what the issue appeared to be as well as why the alternative works.
XMLHttpRequest cannot load first url. The request was redirected to 'second url', which is disallowed for cross-origin requests that require preflight.
The issue here is that you are telling Django to enforce the trailing slash, which makes it automatically redirect urls without a trailing slash to urls with a trailing slash, assuming that one exists. This is why, as stated in the error, the request was redirected to the second url, which you can tell has the missing trailing slash. This is controlled by the APPEND_SLASH Django setting which is True by default.
The problem is that when CORS is doing a preflight request, which is what allows it to determine if the request can be made, there must be a valid response at the requested URL. Because you are redirecting the request, the preflight request fails and you're stuck without your information.
You can fix this by adding the trailing slash in your code. There appear to be a few solutions for doing this with ext, but I personally can't recommend a specific one. You can also manually set the url to use the trailing slash, which sounds like what you were doing previously.
Or you can use JSONP...
You've found the alternative solution, which is to use JSONP to make the request instead of relying on CORS. This gets around the preflight issue and works in all major browsers, but there are some drawbacks to consider. You can find more information on CORS vs JSONP by looking around.
You're going to need CORS if you want to push any changes to your API, as JSONP only supports GET requests. There are other advantages, such as the ability to abort requests, that also comes with CORS.

In django, how to redirect the website to the url of higher layer

How should i write the url so that it can direct me to previous layer?
For example, we know that in view function, if currently we are at www.example.com/users, HttpResponseRedirect('thanks/') would redirect us to www.example.com/users/thanks/ instead of www.example.com/thanks/. How can have it redirect to to www.example.com?
Use a leading /. If you are at www.example.com/users and you return HttpResponseRedirect('thanks/') the client will go to www.example.com/users/thanks/, but if you return HttpResponseRedirect('/thanks/') then the client will go to www.example.com/thanks/
You should be using Django's namespaced URL capabilities: e.g. HttpResponseRedirect(reverse('thanks')), which in this example references a defined URL named thanks.
See Django's URL dispatcher for more details.

How to enable https in Django-auth generated pages?

Using the Django-auth application (Django version 1.3), I want to have my login page go to https://mysite.com/login/. Currently, I'm using:
# urls.py
from django.contrib.auth.views import login
urlpatterns = patterns('', url(r'^login/$', login, name='login-view'),)
# navbar.html
<li id="nav-login"><a href="{% url login-view %}" ><b>Login</b></a></li>
which works nicely, but goes to http://mysite.com/login/.
Is there some way to tell Django-auth what prefix (https) to use, when it reverses the view name? I've read the entire manual page, and haven't found anything that covers it. Or maybe some way to tell the url tag to go to https?
Or is the only option to specify the entire URL manually? I hope not :) And given how powerful Django has been so far, I can't believe it wouldn't have that ability - I must be overlooking it. :)
Set OS environmental variable HTTPS to on
You need to enable the OS environmental variable HTTPS to 'on' so django will prepend https to fully generated links (e.g., like with HttpRedirectRequests). If you are using mod_wsgi, you can add the line:
os.environ['HTTPS'] = "on"
to your wsgi script. You can see the need for this by reading django/http/__init__.py:
def build_absolute_uri(self, location=None):
"""
Builds an absolute URI from the location and the variables available in
this request. If no location is specified, the absolute URI is built on
``request.get_full_path()``.
"""
if not location:
location = self.get_full_path()
if not absolute_http_url_re.match(location):
current_uri = '%s://%s%s' % (self.is_secure() and 'https' or 'http',
self.get_host(), self.path)
location = urljoin(current_uri, location)
return iri_to_uri(location)
def is_secure(self):
return os.environ.get("HTTPS") == "on"
Secure your cookies
In settings.py put the lines
SESSION_COOKIE_SECURE = True
CSRF_COOKIE_SECURE = True
and cookies will only be sent via HTTPS connections. Additionally, you probably also want SESSION_EXPIRE_AT_BROWSER_CLOSE=True. Note if you are using older versions of django (less than 1.4), there isn't a setting for secure CSRF cookies. As a quick fix, you can just have CSRF cookie be secure when the session cookie is secure (SESSION_COOKIE_SECURE=True), by editing django/middleware/csrf.py:
class CsrfViewMiddleware(object):
...
def process_response(self, request, response):
...
response.set_cookie(settings.CSRF_COOKIE_NAME,
request.META["CSRF_COOKIE"], max_age = 60 * 60 * 24 * 7 * 52,
domain=settings.CSRF_COOKIE_DOMAIN,
secure=settings.SESSION_COOKIE_SECURE or None)
Direct HTTP requests to HTTPS in the webserver
Next you want a rewrite rule that redirects http requests to https, e.g., in nginx
server {
listen 80;
rewrite ^(.*) https://$host$1 permanent;
}
Django's reverse function and url template tags only return relative links; so if you are on an https page your links will keep you on the https site.
As seen in other StackOverflow questions, you could implement middleware that would automatically redirect the login page to a secure version.
If you are really serious about security, you should probably migrate the entire website to SSL. From the EFF's How to Deploy HTTPS Correctly:
You must serve the entire application domain over HTTPS. Redirect HTTP requests with HTTP 301 or 302 responses to the equivalent HTTPS resource.
Some site operators provide only the login page over HTTPS, on the theory that only the user’s password is sensitive. These sites’ users are vulnerable to passive and active attack.

Django redirecting to external url that contains parameters (for development)

When developing with Django without a web server (serving directly from Django) I have a problem with external urls that lack the domain part and have parameters.
Let's say I'm using a javascript library that does an ajax call to "/prefix/foo/bar?q=1" (the url is not something I can change). It is not a problem for the production server but only a problem when not using a web server. I can redirect by adding the following pattern to my urlpatters:
(r'^prefix/(?P<path>.*)$', 'django.views.generic.simple.redirect_to', {'url': 'htttp://example.com/prefix/%(path)s'}),
but of course %(path)s will only contain "foo/bar" not "foo/bar?q=1".
Is there a way to handle this problem with Django?
You'll have to write your own redirect:
def redirect_get(request, url, **kwargs):
if request.META['QUERY_STRING']:
url += '?%s' % request.META['QUERY_STRING']
return redirect_to(request, url, **kwargs)